USACE / NAVFAC / AFCESA / NASA UFGS-23 52 33.02 20 (November 2008)
-----------------------------------
Preparing Activity: NAVFAC Superseding
UFGS-23 52 33.02 20 (July 2007)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 23 52 33.02 20
STEAM HEATING PLANT WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL
11/08
NOTE: This guide specification covers the requirements for steam heating plants
from 7 1/2 to 60 1/2 kg/sec 60,000 to 480,000 lbs/hr steam capacity using a
field erected watertube boiler.
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
NOTE: This guide specification covers requirements for equipment for a steam
heating plant which will generate from 7 1/2 to 60 1/2 kg of steam per second
60,000 to 480,000 pounds of steam per hour. This specification is intended
to be used in the procurement and installation of heating plant equipment.
Requirements for materials and procedures for special or unusual design shall
be added to and modifications made to this specification as necessary to fit
specific projects. This guide specification shall be used in conjunction with
the following NAVFAC definitive drawings:
NAVFAC NO./DRAWING TITLE
1429345 - STEAM HEATING PLANT NO.5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL SITE PLAN
1429346 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL MAIN FLOOR PLAN
1429347 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL BASEMENT FLOOR PLAN
1429348 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL LONGITUDINAL SECTION
1429349 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL TRANSVERSE SECTION
1429350 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL PIPING SCHEMATIC
1429351 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL PIPING SCHEMATIC
1429352 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED)
1429353 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL CONTROL SCHEMATIC
1429354 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL HANDLING CONTROLS
1429355 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL DETAILS
1429357 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL FUEL OIL UNLOADING
1429358 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL FUEL OIL STORAGE
1429359 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL SITE DETAILS-COAL HANDLING
1429360 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL RESERVE COAL STORAGE
1429361 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL SITE PLAN - ELECTRICAL
1429362 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL BASEMENT FLOOR PLAN - ELECTRICAL
1429363 - STEAM HEATING PLANT NO. 5 7 12/ - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL MAIN FLOOR PLAN - ELECTRICAL
1429364 - STEAM HEATING PLANT NO. 5 7 1/2 - 34 kg/sec 60,000 - 270,000 POUNDS
PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL ONE-LINE DIAGRAM - ELECTRICAL
1429366 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL SITE PLAN
1429367 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL MAIN FLOOR PLAN
1429368 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL BASEMENT FLOOR PLAN
1429369 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL LONGITUDINAL SECTION
1429370 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL TRANSVERSE SECTION
1429371 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL PIPING SCHEMATIC
1429372 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL PIPING SCHEMATIC
1429373 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL CONTROL SCHEMATIC
1429374 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL CONTROL SCHEMATIC
1429375 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL COAL HANDLING CONTROLS
1429376 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL DETAILS
1429378 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL FUEL OIL UNLOADING
1429379 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL FUEL OIL STORAGE
1429380 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL SITE DETAILS-COAL
HANDLING
1429381 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL RESERVE COAL STORAGE
1429382 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL SITE PLAN - ELECTRICAL
1429383 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL
1429384 - BASEMENT FLOOR PLAN - ELECTRICAL STEAM HEATING PLANT NO. 6 25 1/4
- 60 1/2 kg/sec 200,000 - 480,000 POUNDS PER HOUR WATERTUBE (FIELD ERECTED)
COAL/OIL OR COAL MAIN FLOOR PLAN - ELECTRICAL
1429385 - STEAM HEATING PLANT NO. 6 25 1/4 - 60 1/2 kg/sec 200,000 - 480,000
POUNDS PER HOUR WATERTUBE (FIELD ERECTED) COAL/OIL OR COAL ONE-LINE DIAGRAM
- ELECTRICAL
PART 1 GENERAL
1.1 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[AIR MOVEMENT AND CONTROL ASSOCIATION INTERNATIONAL (AMCA)AMCA 210(2007) Laboratory Methods of Testing Fans for Aerodynamic Performance RatingAMCA 801(2001) Industrial Process/Power Generation Fans: Specification Guidelines][AMERICAN BOILER MANUFACTURERS ASSOCIATION (ABMA)ABMA Boiler 103(2001)Selected Codes and Standards of the Boiler Industry][AMERICAN GEAR MANUFACTURERS ASSOCIATION (AGMA)AGMA 2009(2001b) Bevel Gear Classification, Tolerances and Measuring MethodsAGMA 2011(1998a) Cylindrical Wormgearing Tolerance and Inspection Methods][AMERICAN INSTITUTE OF STEEL CONSTRUCTION (AISC)AISC 303(2005) Code of Standard Practice for Steel Buildings and BridgesAISC 350(2005) Load and Resistance Factor Design (LRFD)Specification for Structural Steel BuildingsAISC 360(2005) Specification for Structural Steel Buildings, with Commentary][AMERICAN PETROLEUM INSTITUTE (API)API Std 607(2005; Errata 2008) Fire Test for Soft-Seated Quarter-Turn ValvesAPI Std 650(2007; Errata 2008) Welded Steel Tanks for Oil Storage][AMERICAN WATER WORKS ASSOCIATION (AWWA)AWWA C510(2007) Standard for Double Check Valve Backflow Prevention AssemblyAWWA C511(2007) Standard for Reduced-Pressure Principle Backflow Prevention AssemblyAWWA C651(2005; Errata 2005) Standard for Disinfecting Water Mains][AMERICAN WELDING SOCIETY (AWS)AWS D1.1/D1.1M(2008) Structural Welding Code - SteelAWS D1.3/D1.3M(2008; Errata 2008) Structural Welding Code - Sheet Steel][ASME INTERNATIONAL (ASME)ASME A13.1(2007) Scheme for the Identification of Piping SystemsASME B16.11(2005) Forged Fittings, Socket-Welding and ThreadedASME B16.18(2001; R 2005) Cast Copper Alloy Solder Joint Pressure FittingsASME B16.21(2005) Nonmetallic Flat Gaskets for Pipe FlangesASME B16.22(2001; R 2005) Standard for Wrought Copper and Copper Alloy Solder Joint Pressure FittingsASME B16.26(2006) Standard for Cast Copper Alloy Fittings for Flared Copper TubesASME B16.3(2006) Malleable Iron Threaded Fittings, Classes 150 and 300ASME B16.34(2004) Valves - Flanged, Threaded and Welding EndASME B16.39(1998; R 2006) Standard for Malleable Iron Threaded Pipe Unions; Classes 150, 250, and 300ASME B16.5(2003) Standard for Pipe Flanges and Flanged Fittings: NPS 1/2 Through NPS 24ASME B16.9(2007) Standard for Factory-Made Wrought Steel Buttwelding FittingsASME B29.100(2002; Errata 2004) Precision Power Transmission, Dbl-P-Power Transmission, Dbl-P-conveyor Roller Chains, Attachments and SprocketsASME B31.1(2007; Addenda 2008) Power PipingASME B40.100(2005) Pressure Gauges and Gauge AttachmentsASME BPVC SEC I(2007; Addenda 2008) Boiler and Pressure Vessel Code; Section I, Power BoilersASME BPVC SEC II-A(2007; Addenda 2008) Electric-Resistance-Welded Carbon Steel and Carbon-Manganese Steel Boiler TubesASME BPVC SEC II-C(2007; Addenda 2008) Boiler and Pressure Vessel Code; Section II, Materials, Part C - Specifications for Welding Rods, Electrodes and Filler MetalsASME BPVC SEC VII(2007; Addenda 2008) Boiler and Pressure Vessel Code; Section VII, Recommended Guidelines for the Care of Power BoilersASME BPVC SEC VIII(2007; Addenda 2008) Boiler and Pressure Vessel Codes: Section VIII Rules for Construction of Pressure Vessels, Division 1ASME PTC 4(1998) Fired Steam Generators][ASTM INTERNATIONAL (ASTM)ASTM A 106/A 106M(2008) Standard Specification for Seamless Carbon Steel Pipe for High-Temperature ServiceASTM A 193/A 193M(2008b) Standard Specification for Alloy-Steel and Stainless Steel Bolting Materials for High-Temperature ServiceASTM A 194/A 194M(2008b) Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High-Pressure or High-Temperature Service, or BothASTM A 211(1975; R 1985)Specification for Spiral-Welded Steel or Iron PipeASTM A 242/A 242M(2004e1) Standard Specification for High-Strength Low-Alloy Structural SteelASTM A 312/A 312M(2008a) Standard Specification for Seamless, Welded, and Heavily Worked Austenitic Stainless Steel PipesASTM A 36/A 36M(2008) Standard Specification for Carbon Structural SteelASTM A 48/A 48M(2003; R 2008) Standard Specification for Gray Iron CastingsASTM A 53/A 53M(2007) Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and SeamlessASTM A 570/A 570M(1998) Standard Specification for Steel, Sheet and Strip, Carbon, Hot-RolledASTM B 111/B 111M(2008a) Standard Specification for Copper and Copper-Alloy Seamless Condenser Tubes and Ferrule StockASTM B 88(2003) Standard Specification for Seamless Copper Water TubeASTM B 88M(2005) Standard Specification for Seamless Copper Water Tube (Metric)ASTM C 155(1997; R 2007) Standard Specification for Insulating FirebrickASTM C 27(1998; R 2008) Fireclay and High-Alumina Refractory BrickASTM C 401(1991; R 2005) Alumina and Alumina-Silicate Castable RefractoriesASTM D 1047(2007) Poly(Vinyl Chloride) Jacket for Wire and CableASTM D 1220(1965; R 1990) Measurement and Calibration of Upright Cylindrical TanksASTM D 396(2008b) Standard Specification for Fuel Oils][FM GLOBAL (FM)FM DS 12-17(2001) Watertube Boilers][MANUFACTURERS STANDARDIZATION SOCIETY OF THE VALVE AND FITTINGS INDUSTRY (MSS)MSS SP-58(2002) Standard for Pipe Hangers and Supports - Materials, Design and ManufactureMSS SP-69(2003; R 2004) Standard for Pipe Hangers and Supports - Selection and ApplicationMSS SP-70(2006) Standard for Cast Iron Gate Valves, Flanged and Threaded EndsMSS SP-80(2008) Bronze Gate, Globe, Angle and Check ValvesMSS SP-85(2002) Standard for Cast Iron Globe & Angle Valves, Flanged and Threaded Ends][NATIONAL BOARD OF BOILER AND PRESSURE VESSEL INSPECTORS (NBBPVI)NBBPVI NB-27(1991) National Board Rules and Recommendations for the Design and Construction of Boiler Blowoff Systems][NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)NEMA 250(2003) Enclosures for Electrical Equipment (1000 Volts Maximum)NEMA MG 1(2007; Errata 2008) Standard for Motors and GeneratorsNEMA SM 23(1991; R 2002) Steam Turbines for Mechanical Drive Service][NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)NFPA 54(2008) National Fuel Gas CodeNFPA 70(2007; AMD 1 2008) National Electrical Code - 2008 EditionNFPA 85(2007) Boiler and Combustion Systems Hazards Code][THE SOCIETY FOR PROTECTIVE COATINGS (SSPC)SSPC PS 11.01(1982; E 2004) Black (or Dark Red) Coal Tar Epoxy-Polyamide Painting SystemSSPC SP 10(2007) Near-White Blast Cleaning][U.S. DEPARTMENT OF DEFENSE (DOD)MIL-C-18480(Rev B; Notice 1) Coating Compound, Bituminous, Solvent, Coal-Tar BaseMIL-DTL-17813(Rev G) Military Standard for Expansion Joints, Pipe, Metallic BellowsMIL-E-17814(Rev F; CANC Notice 1) Expansion Joints, Pipe, Slip-Type, PackedMIL-STD-101(Rev B) Color Code for Pipelines & for Compressed Gas CylindersMIL-T-19646(Rev A) Thermometer, Gas Actuated, Remote ReadingMIL-V-18436(Rev F) Valves, Check, Bronze, Cast Iron, and Steel Body][U.S. FEDERAL AVIATION ADMINISTRATION (FAA)FAA AC 150/5345-43(Rev F) Obstruction Lighting Equipment][U.S. GENERAL SERVICES ADMINISTRATION (GSA)FS A-A-50494(Basic) Exhaust Head, SteamFS A-A-50555(Basic) Pumping Units, Sewage, Duplex, Centrifugal, Automatic Wet-Pit TypeFS A-A-50558(Basic) Valves, Pressure Regulating, SteamFS A-A-50562(Basic) Pump Units, Centrifugal, Water, Horizontal; General Service and Boiler-Feed: Electric-Motor- or Steam-Turbine-DrivenFS A-A-59222(Basic) Fans, Centrifugal, Draft, Forced and InducedFS A-A-59224(Basic; Notice 1) Meters, Fluid Quantity VolumetricFS A-A-60001(Basic) Traps, SteamFS F-B-2910(Basic) Burners, Single Oil, Gas, and Gas-Oil Combination for Packaged Boilers (320,001 to 125,000,000 BTU/HR Thermal Output Capacity)FS TT-P-28(Rev G) Paint, Aluminum, Heat Resisting (1200 Degrees F.)FS W-H-2904(Basic) Heaters, Fluid, Deaerating (For Water Only) 1,000 to 1,600,000 Pounds Per Hour CapacityFS WW-S-2739(Basic) Strainers, Sediment: Pipeline, Water, Air, Gas, Oil, or SteamFS XX-C-2816(Basic) Compressor, Air, Reciprocating or Rotary, Electric Motor Driven, Stationary, 10 HP and Larger][U.S. NATIONAL ARCHIVES AND RECORDS ADMINISTRATION (NARA)29 CFR 1910-SUBPART DWalking - Working Surfaces29 CFR 1910-SUBPART QWelding, Cutting, and Brazing][U.S. NAVAL FACILITIES ENGINEERING COMMAND (NAVFAC)NAVFAC MO 324(1992) Inspection and Certification of Boilers and Unfired Pressure Vessels][UNDERWRITERS LABORATORIES (UL)UL 296(2003; Rev thru Feb 2006) Oil BurnersUL 726(1995; Rev thru Mar 2006) Oil-Fired Boiler Assemblies][WATER QUALITY ASSOCIATION (WQA)WQA S-100(1995) Household Commercial and Portable Exchange Water Softeners an Equipment Validation Standard]1.2 RELATED REQUIREMENTS
Section 23 03 00.00 20 BASIC MECHANICAL MATERIALS AND METHODS applies to this section with the additions and
modifications specified herein.
1.3 DEFINITIONS
NOTE: Information describing any specific project and site conditions which
the Contractor would need to know in order to submit a firm price shall be specified
in Division 1 of the project specifications. Such conditions include:
1. Allocated space for storage of materials.
2. Railway spurs and sidings available to the Contractor for delivery of materials.
3. Any restrictions on daily working hours.
4. Procedure for scheduling outages and tests.
5. Any noise or traffic restrictions.
6. Availability of utilities required for construction.
1.3.1 Effective Radiant Heating Surface
Heat exchange surface, exclusive of superheat elements, which is directly exposed to radiant heat of the flame
on one side and to water or water-steam mixture being heated on the other. Effective radiant heating surface
shall be calculated on the side receiving heat and shall consist of plain or finned tubes and headers which may
be bare, metal covered, or metallic-ore covered. Refractory covered surfaces shall not be counted. Computations
shall be made as follows:
a. Flat projected area of bare, metal covered, or metallic-ore covered tubes and headers shall
be considered as effective radiant heating surface.
b. Metal and metallic surfaces extending from tubes or headers shall be considered to have
an effective radiant heating surface equal to 60 percent of their flat projected area except
that the following extended surfaces shall not be considered as effective radiant heating surface.
(1) Metal blocks not integral with tubes or headers.
(2) Extended surfaces less than 6 mm 1/4 inch thick.
(3) That portion of the extended surface more than one tube or header radius from the tube
or header from which it extends.
(4) Extended surfaces larger than 32 mm 1 1/4 inches.
c. Flat projected areas of portions of first two rows of furnace exit tubes that receive radiant
heat from the fire shall be considered as effective radiant heating surface.
1.3.2 Flue Gas Velocity
NOTE: The maximum velocity to prevent erosion will vary according to whether
boiler is multipass or single pass, the type of stoker and the type of fuel.
See DM-3.6, Table 4, Maximum Velocities (MPS FPS) in Convection Sections for
Coal, Wood or Solid Waste Boilers.
Velocity of the gas entering the convection section shall not exceed [10] [15] [18] [23] meters per second (m/s)
[35] [50] [60] [75] feet per second (fpm).
1.3.3 FRP
Fiberglass reinforced plastic.
1.3.4 Furnace Volume
The cubic volume of the space provided for combustion of the fuel between the top grate line and the first plane
of entry into, or between the tubes, of the furnace face of the bridge wall. When screen or superheater tubes
are utilized, they shall be considered as the first plane of entry. The manufacturer shall state the furnace
volume of the boiler.
1.3.5 PVC
Poly-vinyl chloride.
1.3.6 Standard Commercial Product
Standard commercial product is a product which has been sold or is being currently offered for sale on the commercial
market through advertisements or manufacturer's catalogs, or brochures, and represents the latest production
model.
1.3.7 System Supplier
A manufacturer, fabricator, erector, corporation or firm that regularly is employed in the design, fabrication,
erection (or erection supervision), testing and startup of systems comparable in size and type to those specified
and indicated. System supplier shall arrange the equipment selected, design equipment interconnections, produce
related shop drawings, supervise erection, and startup and test the equipment.
1.4 SYSTEM DESCRIPTION
1.4.1 Design Requirements
1.4.1.1 Boiler
Design boiler in accordance with the ASME BPVC SEC I. Provide design data with computations and performance
guarantees covering the full range of operation at full load, 75 percent load, 50 percent load and 30 percent
load. Assemble tubes, drums, and headers so that the entire boiler can be drained dry. The furnace shall be
water cooled on the side, top, front and back walls.
a. Boiler design and service conditions
(1) Steam capacity:
Continuous peak for 2 hours: [_____] kg/sec lb/hr
Maximum continuous: [_____] kg/sec lb/hr
Minimum (without smoking): [_____] kg/sec lb/hr
(2) Design pressure: [_____] kPa (gage) psig
(3) Operating pressure: [_____] kPa (gage) psig
(4) Steam temperature: [_____] degrees C F
(5) Feedwater temperature to economizer: [_____] degrees C F
Continuous blowdown: [_____] percent
(6) Maximum moisture content of steam
leaving drum at peak rating: [_____] percent
(7) Total solids concentration in drum: [_____] PPM
(8) Fuel:
Coal (see coal analysis):
[Oil (see oil analysis)]:
(9) Heating surface, minimum:
Radiant: [_____] sq. m ft.
Convective: [_____] sq. m ft.
(10) Furnace volume, minimum: [_____] cu. m ft.
(11) Maximum boiler flue gas exit
Temperature: [_____] degrees C F
Continuous rating: [_____] degrees C F
(12) Maximum economizer flue gas exit
Temperature: [_____] degrees C F
Continuous rating: [_____] degrees C F
(13) Efficiency at maximum continuous
rating [includes economizer]
Coal: [_____] percent
[Oil]: [_____] percent (14)
Elevation above sea level: [_____] meters feet
(15) Boiler room & combustion air ambient: [_____] degrees C F
(16) Maximum allowable total draft loss
furnace, boiler, exit damper,
and economizer outlet at
continuous rating: [_____] Pa inches of Water
(17) Steam drum, minimum diameter: [_____] mm inches
(18) Mud drum, minimum diameter: [_____] mm inches
(19) Seismic zone: [_____]
1.4.1.2 Economizer
NOTE: Feedwater temperatures should be 110 degrees C 230 degrees F when sulfur
(S) content of fuel is 0.5 percent to 1.5 percent; 116 degrees C 240 degrees
F, S = 1.5 percent to 2 percent; 121 degrees C 250 degrees F, S = 2.0 percent
to 2.7 percent. Where fuels having more than 1.5 percent sulfur content are
to be fired, finned tubes shall not be used unless the steel tubes are covered
with cast iron fin casing.
a. Flue gas quantity: [_____] kg/s lbs/hr
b. Flue velocity: [_____] m/s ft/min
c. Flue gas temperature entering economizer: [_____] degrees C F
d. Flue gas temperature leaving economizer: [_____] degrees C F
e. Feedwater Temperature entering economizer: [_____] degrees C F
f. Feedwater Temperature leaving economizer: [_____] degrees C F
g. Fouling factor on feedwater side: [_____]
h. Fouling factor on gas side: [_____]
i. Boiler operating pressure: [_____] kPa (gage) psig
j. Design pressure: [_____] kPa (gage) psig
k. Steam loads shall be as specified under boiler[s]
l. Performance: The efficiency due to the economizer shall be included with and stated as
part of the overall boiler efficiency.
1.4.1.3 Forced Draft Fan
Design fan to handle air at temperatures from [_____] to [_____] degrees C F. Fan shall be [single] [double]
width inlet, [single] [double] width outlet, with [clockwise] [counter-clockwise] rotation; viewed from the [motor]
[turbine] end.
1.4.1.4 Induced Draft Fan
Design fan of materials which will withstand flue gas temperatures up to 316 degrees C 600 degrees F without
damage. Fan shall be [single] [double] width inlet, [single] [double] width outlet, with [clockwise] [counter
clockwise] rotation when viewed from [motor] [turbine] end. Provide outboard pedestal bearings with sole plates
[and dual extension shaft].
1.4.1.5 Screw Conveyors for Coal Handling Equipment
Each screw conveyor shall meet the following minimum design and performance specifications when handling [_____]
size coal:
CONVEYOR NO. 1 CONVEYOR NO. 2
a. Capacity [_____] Mg/hr [_____] Mg/hr
b. Screw diameter [_____] mm [_____] mm
c. Length [_____] meters [_____] meters
d. Coupling diameter [_____] mm [_____] mm
e. Motor horsepower [_____] kW [_____] kW
f. Screw flight thickness [_____] mm [_____] mm
g. Trough thickness [_____] mm [_____] mm
h. Trough cover thickness [_____] mm [_____] mm
i. Trough end plate thickness [_____] mm [_____] mm
j. Maximum speed [_____] rpm [_____] rpm
CONVEYOR NO. 1 CONVEYOR NO. 2
a. Capacity [_____] tons/hr [_____] tons/hr
b. Screw diameter [_____] inches [_____] inches
c. Length [_____] feet [_____] feet
d. Coupling diameter [_____] inches [_____] inches
e. Motor horsepower [_____] hp [_____] hp
f. Screw flight thickness [_____] inches [_____] inches
g. Trough thickness [_____] inches [_____] inches
h. Trough cover thickness [_____] inches [_____] inches
i. Trough end plate thickness [_____] inches [_____] inches
j. Maximum speed [_____] rpm [_____] rpm
1.4.1.6 Screw Conveyors for Ash Handling Systems (Mechanical)
Each screw conveyor shall meet the following minimum design and performance specifications when handling dry
fly ash of density not greater than [_____] kg per cubic meter pounds per cubic foot:
CONVEYOR NO. 1 CONVEYOR NO. 2
a. Capacity [_____] Mg/hr [_____] Mg/hr
b. Screw diameter [_____] mm [_____] mm
c. Length [_____] meters [_____] meters
d. Coupling diameter [_____] mm [_____] mm
e. Motor power [_____] kW [_____] kW
f. Screw flight thickness [_____] mm [_____] mm
g. Trough thickness [_____] mm [_____] mm
h. Trough cover thickness [_____] mm [_____] mm
i. Trough end plate thickness [_____] mm [_____] mm
j. Maximum speed [_____] rpm [_____] rpm
CONVEYOR NO. 1 CONVEYOR NO. 2
a. Capacity [_____] tons/hr [_____] tons/hr
b. Screw diameter [_____] inches [_____] inches
c. Length [_____] feet [_____] feet
d. Coupling diameter [_____] inches [_____] inches
e. Motor horsepower [_____] hp [_____] hp
f. Screw flight thickness [_____] inches [_____] inches
g. Trough thickness [_____] inches [_____] inches
h. Trough cover thickness [_____] inches [_____] inches
i. Trough end plate thickness [_____] inches [_____] inches
j. Maximum speed [_____] rpm [_____] rpm
1.4.1.7 Stacks With Flue Gas Scrubbers
Stacks with flue gas scrubbers, boilers 5 kg/sec 40,000 lb/hour and over:
a. Temperature
(1) Maximum ambient: [_____] degrees C F
(2) Minimum ambient: [_____] degrees C F
(3) Inlet gas at maximum gas flow (coal): [_____] degrees C F
(4) Inlet gas at maximum gas flow (oil): [_____] degrees C F
(5) Inlet gas at minimum gas flow (coal): [_____] degrees C F
(6) Inlet gas at minimum gas flow (oil): [_____] degrees C F
b. Gas Flow at Inlet
(1) Maximum: [_____] kg/s lbs/hr
(2) Minimum: [_____] kg/s lbs/hr
c. Required net available draft at stack inlet
(1) Maximum gas flow: [_____] Pa inches water
d. Gas exit velocity (cone exit)
(1) Maximum at maximum conditions: [_____] m/s ft/sec
e. Flue gas dew point
(1) Fuel oil: [_____] degrees C F
(2) Fuel-coal: [_____] degrees C F
f. Test pressures
(1) Shop test: [_____] Pa inches water
g. Thermal efficiency of stack: 96 to 98 percent
h. Stack friction
(1) Maximum at design conditions: [_____] Pa inches water
i. Stack height
(1) Ground elevation: [_____] m ft
(2) Roof elevation: [_____] m ft
(3) Stack height: [_____] m ft
(4) Foundation or footing elevation: [_____] m ft
j. Wind pressure: [_____] kg/m2 psf
Elevation Above Ground Level (m) Wind Pressure (kg/m2)
0 - 9 [_____]
15 [_____]
23 [_____]
30 [_____]
38 [_____]
46 [_____]
53 [_____]
61 [_____]
Elevation Above Ground Level (ft) Wind Pressure (psf)
0 - 30 [_____]
50 [_____]
75 [_____]
100 [_____]
125 [_____]
150 [_____]
175 [_____]
200 [_____]
k. Wind velocity, gusting: [_____] km/hr mph
l. Stack inside diameter, minimum (below velocity cone): [_____] mm inches
m. Maximum stack deflection (from vertical center line): [_____] mm inches
n. Soil bearing stress, maximum: [_____] kg/m2 psf
o. Seismic zone: [_____]
1.4.1.8 Fuel Oil Pumps
a. Transfer pumps (for fuel oil tank truck or railroad tank car unloading and transfer to tanks):
NOTE: At the text below, the values enclosed in brackets are for No. 6 Low
Sulfur fuel oil. Adjust values to suit fuel oil used when other than No. 6.
(1) Number of assemblies: [_____]
(2) Tag numbers: [_____]
(3) Capacity each at 450 ssu: [_____] L/s gpm
(4) Suction lift required: [_____] kPa ft of water
(5) Discharge pressure: [_____] kPa (gage) psig
(6) Operating temp.: [27 to 5480 to 130] [_____to_____] degrees C F
(7) Viscosity range: [450 to 5000] [_____to_____] ssu
(8) Specific gravity: [.92 to .99] [_____to_____]
(9) Viscosity at brake power selection point: [9000] [_____] ssu
(10) Maximum pump speed: 1750 rpm
(11) Motor kW hp: [_____]
(12) Fuel oil: No. [6, Low Sulfur] [_____]
b. Transfer pumps (for fuel oil transfer from tanks to heating plant):
NOTE: At the text below, the values enclosed in brackets are for No. 6 Low
Sulfur fuel oil. Adjust values to suit fuel oil used when other than No. 6.
(1) Number of assemblies: [_____]
(2) Tag numbers: As indicated
(3) Capacity at 450 ssu: [_____] L/s gpm
(4) Suction lift required: [_____] kPa (gage) ft of water
(5) Discharge pressure: [_____] kPa (gage) psig
(6) Operating temperature: [49120] [_____] degress C F
(7) Viscosity range: [450 to 3000] [_____ to _____] ssu
(8) Specific gravity: [.92 to .99] [_____ to _____]
(9) Viscosity at brake power point: [5000] [_____] ssu
(10) Maximum pump speed: 1750 rpm
(11) Motor kW hp: [_____]
(12) Fuel oil: No. [6, low sulfur] [_____]
c. Fuel oil recirculation pump sets (at remote storage):
NOTE: At the text below, the values enclosed in brackets are for No. 6 Low
Sulfur fuel oil. Adjust values to suit fuel oil used when other than No. 6.
(1) Number of assemblies: [_____]
(2) Tag numbers: As indicated
(3) Capacity: 1.58 L/s 25 gpm at 450 ssu
(4) Suction lift required: [_____] kPa ft. water
(5) Discharge pressure: [_____] kPa (gage) psig
(6) Operating temperature: [49120] [_____] degrees C F
(7) Viscosity range: [450 to 3000] [_____ to _____] ssu
(8) Specific gravity: [.92 to .99] [_____ to _____]
(9) Viscosity at brake power point: [5000] [_____] ssu
(10) Maximum pump speed: 1750 rpm
(11) Motor kW hp: [_____]
(12) Fuel oil: No. [6, low sulfur] [_____]
1.4.1.9 Fuel Oil Pump and Heater Set for Fuel Oil System
NOTE: At the text below, the values enclosed in brackets are for No. 6 Low
Sulfur fuel oil. Adjust values to suit fuel oil used when other than No. 6.
a. Pump/heater set
(1) Capacity each pump and each steam heater: [_____] L/s gpm
(2) Suction lift: [_____] kPa ft water
(3) Discharge pressure at outlet of heater: [_____] kPa (gage) psig
(4) Maximum pump speed: 1750 rpm
(5) Specific gravity range: [.92 to .99] [_____ to _____]
(6) Viscosity at brake power point: 5000 ssu
(7) Viscosity range: [500 to 5000] [_____ to _____] ssu
(8) Oil temperature at inlet of heater: [_____] degrees C F
(9) Oil temperature at outlet of heater: [_____] degrees C F
(10) Maximum oil pressure drop through heater: [_____] kPa psi
(11) Heating medium: Steam
(12) Steam pressure available: [_____] kPa (gage) psig
(13) Steam temperature: [_____] degrees C F
(14) Heater type: [Extended surface][Bare tube]
b. Electric startup heater
(1) Oil temperature at heater inlet: [_____] degrees C F
(2) Oil temperature at heater outlet: [_____] degrees C F
(3) Maximum oil pressure drop through heater: [_____] kPa psi
(4) Capacity of heater: [_____] L/s gpm
(5) Heating power supply at three phase, 60 Hz [_____] volts
(6) Control power supply 120 volts, single phase, 60 Hz
1.4.1.10 Ash Handling System (Mechanical)
a. Capacity:
(1) Ash handling system: Estimated capacities at maximum plant output are listed below; ash
handling system capacity shall be sized for twice the amounts listed.
[_____] Mg tons per hour for fly ash
[_____] Mg tons per hour for bottom ash
[_____] Mg tons per hour in bucket elevator leaving the boiler house (minimum).
(2) Ash silo: Storage capacity of ash silo is specified in the paragraph entitled "Ash Storage
Silo."
(3) Rotary unloader: [_____] Mg tons per hour
b. General data
(1) Available water pressure: [_____] kPa (gage) psig
(2) Available air pressure: [_____] kPa (gage) psig
(3) Seismic zone: [_____]
(4) Wind velocity (gusts): [_____] km/hr mph
(5) Altitude of plant: [_____] m ft
(6) Steam rating of plant: [_____] kg/s lb/hr
(a) Maximum continuous rating of boiler no. 1 [_____] kg/s lb/hr
(b) Maximum continuous rating of boiler no. 2 [_____] kg/s lb/hr
[(c) Maximum continuous rating of boiler no. 3 [_____] kg/s lb/hr]
[(d) Maximum continuous rating of boiler no. 4 [_____] kg/s lb/hr]
(7) Coal analysis
(a) Ash [_____] percent
(b) Carbon [_____] percent
(c) Hydrogen [_____] percent
(d) Sulfur [_____] percent
(e) Moisture [_____] percent
(f) Nitrogen [_____] percent
(g) Oxygen [_____] percent
(8) Ash Analysis
(a) Carbon [_____] percent
(b) Calcium [_____] percent
1.4.1.11 Ash Handling System (Pneumatic)
a. Capacity:
(1) Ash handling system: Estimated capacities at maximum plant output are listed below; ash
handling system capacity shall be sized for twice the amounts listed.
[_____] Mg tons per hour for fly ash
[_____] Mg tons per hour for bottom ash
[_____] Mg tons per hour in bucket elevator leaving the boiler house (minimum).
(2) Ash silo: Storage capacity of ash silo is specified in the paragraph entitled "Ash Storage
Silo."
(3) Rotary unloader: [_____] Mg tons per hour.
b. General Data
(1) Available water pressure: [_____] kPa (gage) psig
(2) Available air pressure: [_____] kPa (gage) psig
(3) Seismic zone: [_____]
(4) Wind velocity (gusts): [_____] km/hr mph
(5) Altitude of plant: [_____] m ft
(6) Steam rating of plant: [_____] kg/s lb/hr
(a) Maximum continuous rating of boiler no. 1 [_____] kg/s lb/hr
(b) Maximum continuous rating of boiler no. 2 [_____] kg/s lb/hr
[(c) Maximum continuous rating of boiler no. 3 [_____] kg/s lb/hr]
[(d) Maximum continuous rating of boiler no. 4 [_____] kg/s lb/hr]
(7) Coal analysis
(a) Ash: [_____] percent
(b) Carbon: [_____] percent
(c) Hydrogen: [_____] percent
(d) Sulfur: [_____] percent
(e) Moisture: [_____] percent
(f) Nitrogen: [_____] percent
(g) Oxygen: [_____] percent
(8) Ash analysis
(a) Carbon: [_____] percent
(b) Calcium: [_____] percent
(9) Minimum velocities required for materials
(a) Fly ash: 19.30 m/s 3800 ft./min.
(b) Bottom ash (traveling grate stoker): 28.44 m/s 5600 ft./min.
(c) Bottom ash (spreader stoker): 26 m/s 5100 ft./min..
1.4.1.12 Miscellaneous Equipment
a. Deaerating heater: Design the deaerating heater for the following conditions:
(1) Design pressure: 207 kPa (gage) 30 psig
(2) Normal steam operating pressure: [_____] kPa (gage) psig
(3) Maximum steam operating pressure: [_____] kPa (gage) psig
(4) Capacity (minimum): [_____] kg/s lb/hr of feedwater
(5) Inlet Conditions at Heater:
Maximum Temperature
Pressure Range Flow Rate
kPa (gage) Degrees C kg/s
Condensate return [_____] [_____ to _____] [_____]
High pressure
trap returns [_____] [_____ to _____] [_____]
Makeup water [_____] [_____ to _____] [_____]
(softened)
Maximum Temperature
Pressure Range Flow Rate
psig Degrees F lb/hr
Condensate return [_____] [_____ to _____] [_____]
High pressure
trap returns [_____] [_____ to _____] [_____]
Makeup water [_____] [_____ to _____] [_____]
(softened)
(6) Outlet temperature of feedwater from heater at design capacity: [_____] degrees C F
(7) Heating steam pressure: [_____] kPa (gage) psig
(8) Heating steam enthalpy: [_____] kJ/kg Btu/lb
(9) Storage capacity to overflow of storage tank: [_____] liters gallons.
NOTE: At the text below, analysis of the water available for makeup shall govern
the water treatment system selected. A competent water treating consultant
shall be obtained to formulate specific system recommendations when the makeup
water analysis indicates any of the following:
1. Iron in excess of 0.1 ppm as Fe.
2. Mg alkalinity in excess of 50 ppm as CaCO3.
3. Silica in excess of 6 ppm as SiO2.
b. Water softening system: Base the water softening system on the following:
(1) Raw water analysis: Source of raw water is [_____]. It is available at pressures of [_____]
to [_____] kPa (gage) psig. The analysis of the water available for makeup is approximately
as follows:
TABLE 1
MAKEUP WATER ANALYSIS
Constituent
Cations Analysis Parts Per Million (PPM)
Calcium (Ca++) as CaCO3 [_____]
Magnesium (Mg++) as CaCO3 [_____]
Sodium (Na+) as CaCO3 [_____]
Hydrogen (H+) as CaCO3 [_____]
TOTAL CATIONS as CaCO3 [_____]
Anions Analysis Parts Per Million (PPM)
Bicarbonate (HCO3 -) as CaCO3 [_____]
Carbonate (CO3 --) as CaCO3 [_____]
Hydroxide (OH -) as CaCO3 [_____]
Sulfate (SO4 --) as CaCO3 [_____]
Chloride (Cl -) as CaCO3 [_____]
Phosphate (PO4 ---) as CaCO3 [_____]
Nitrate (NO3 -) as CaCO3 [_____]
TOTAL ANIONS as CaCO3 [_____]
Constituent Analysis Parts Per Million (PPM)
Total hardness as CaCO3 [_____]
Methyl orange alkalinity as CaCO3 [_____]
Phenophthalein alkalinity as CaCO3 [_____]
Iron, total as Fe [_____]
Carbon dioxide as Free CO2 [_____]
Silica as SiO2 [_____]
Suspended solids [_____]
(Turbidity)
Total dissolved solids (TDS) [_____]
Free acids [_____]
Color [_____]
pH [_____]
Specific Conductance Micromhos/cm [_____]
(2) Softener effluent analysis:
Hardness: Maintain hardness of the softened feedwater near zero and in no case allow it to
exceed 1.0 part per million as CaCO3.
NOTE: At the text below, total solids of 175 ppm in the feedwater concentrated
20 times give 3,500 ppm in the boiler water.
Total solids: Maintain total solids in the softened feedwater at a level to ensure a total
solids concentration in the boiler water of less than 3,500 ppm without excessive blowdown.
1.4.2 Detail Drawings
1.4.2.1 Boiler Drawing
Submit safety valve calculation sheets or Manufacturer's standard sheets) and detail drawings for the following:
a. Refractory details, expansion joints
b. Certified outline, general arrangement (setting plan), and anchor bolt detail drawings including
foundation loading diagrams
c. Plans and elevations detailing piping connections
d. Detailed dimensional drawings of auxiliaries furnished with the unit
e. Piping schematics for auxiliaries, such as sootblowers or hydraulic stoker drives (when
used)
f. Shop fabrication details of boiler/furnace: Include details showing tubing, spacing, radii
dimensions, and gage; sections through walls and expansion joints showing refractory construction
and replacement details; internal and external dimensions of the boiler
g. Wiring diagrams for subsystems
h. Economizers and economizer inlet breeching
i. Soot blowers
j. Auxiliaries furnished with the boilers
k. Forced draft fan, drives and duct work
l. Induced draft fan, drives and duct work
m. Structural steel and loading diagrams
n. Overfire air fan system
1.4.2.2 Boiler Room Auxiliary Equipment
Submit descriptive information for the following items on the drawings including arrangements, wiring diagrams,
piping diagrams, and details of valves and piping.
a. Water softening equipment
b. Brine storage tank
c. Condensate receiver
d. Condensate transfer pumps including certified performance curves
e. Deaerator
f. Boiler feed pumps including certified performance curves
g. Steam turbines and their drives
h. Continuous blowdown system
i. Chemical feed units
j. Air compressors
k. Air dryers
l. Cranes and hoists
m. Plant heating and ventilation equipment showing related ductwork
1.4.2.3 Stokers
Include the following:
a. General arrangement
b. Foundation drawings
c. Front plates
d. Ash hoppers
e. Fuel gate mechanism
f. Grate details
g. Zone dampers
h. Air seal details
i. Overfire air nozzle arrangement, overfire air fan and drives
j. Coal feeder details
k. Fuel feeder drives
l. Piping schematics
m. Wiring schematics
n. Access doors
1.4.2.4 Ash Handling System
Include the following:
a. General arrangement
b. Construction details ash storage silo complete with loading diagrams
c. Control panel arrangement and schematics
d. Wiring and control diagrams
e. Ash piping arrangement drawings and schematic drawings
f. Wear back fitting details
g. Piping and fittings
h. Details of [steam] [motor driven mechanical] exhauster [and air washer-steam condenser]
i. Details of separators, tertiary bag filter, and ash silo vent bag filter
j. Silo fluidizing system and rotary ash conditioner
k. Bottom ash hopper and vertical lift doors
l. Ash crusher
1.4.2.5 Burners
Include the following:
a. General arrangement
b. Piping details
c. Burner control schematics
d. Flame safety schematics
e. Component details
f. Throat tile details
1.4.2.6 Dampers, Stacks and Breechings
Include the following:
a. General arrangement
b. Breeching, reinforcing details
c. Breeching hangers and support details
d. Dampers and operators
e. Access doors and frames
f. Expansion joints
g. Stack details including anchor bolt and foundation details, stack sampling ports, platforms,
and accessories
[(1) Submit drawings stamped by a registered professional engineer for stacks with flue gas
scrubbers, boilers 5 kg/sec 40,000 lb/hour and over.]
1.4.2.7 Coal Handling Equipment
Include the following:
a. Certified outline and general arrangement drawings for complete coal handling system
b. Dimensional equipment and fabrication drawings, including all equipment weights, equipment
locations, support details, and anchor bolt arrangements for items and equipment specified under
the coal handling section
c. Control panel, coal presence indicators, and equipment response switch details
d. Control schematic diagrams and complete wiring diagrams
1.4.2.8 Fuel Oil Equipment
Drawings may be manufacturer's standard size for pumps, pump curves, valves, strainers and pump wiring.
a. Certified outline and general arrangement drawings
b. Certified pump and performance curves and tabulations
c. Equipment detail sheets including viscosity controller, heater and valves
d. Electrical wiring diagrams
e. Oil tanks, foundations, tank heaters, appurtenances, water draw-off and level indication.
1.4.2.9 Piping and Specialty Items
Drawings may be manufacturer's standard size.
a. Details of valves and special fittings
b. Feedwater regulator details and schematics
c. Details and schematics of feedwater automatic recirculation
1.4.2.10 Flexible Ball Expansion Joint Installation Details
Include allowable angular flex and minimum offset dimensions for approval.
1.4.2.11 Reinforced Concrete Foundation
Concrete and reinforcing for the foundation shall be detailed on the Contractor's submitted shop drawings as
specified under Section 03 30 00 CAST-IN-PLACE CONCRETE.
1.4.2.12 Reproducible Drawings
Submit one reproducible plastic shop drawing of each approved drawing sheet to the Contracting Officer for the
following items:
a. Boiler layout, foundations, construction and details including [preheaters,] [economizers,]
auxiliaries and details
b. Breeching layout, construction and details
c. Burner construction, control and flame safety schematics, and details
d. Burner details
e. Wiring diagrams
f. Fuel tanks, foundations and appurtenances
g. Feedwater automatic recirculation system
h. Piping schematics
i. Control diagrams schematics including panel construction and layout
j. Coal handling equipment
k. Stoker drawings and details
l. Ash handling system, including panels, schematics and details
1.4.3 Test Reports
1.4.3.1 Boiler Predicted Performance Data
Submit certified copies of design, production and conformance tests for approval before delivery of the equipment.
1.4.3.2 Fan Performance Data
Submit to the Contracting Officer manufacturer's fan performance data based on performance tests made in accordance
with the requirements of AMCA 210. AMCA certified test data from prototype fan designs is acceptable.
1.4.4 Performance Requirements
1.4.4.1 Boiler
NOTE: The specified efficiency for the boiler at maximum continuous load shall
be not less than 80 percent for coal and 82 percent for oil. When an economizer
is provided, use 82 and 84 percent respectively for coal and oil firing. Depending
on the particular application and fuel used, these efficiencies could be higher.
The efficiency listed for coal burning shall be based on stoker firing with [_____] percent excess air. [The
efficiency for fuel oil firing shall be based on [_____] percent excess air]. The efficiency shall allow for
[_____] percent continuous blowdown and 1.5 percent unaccounted losses and manufacturer's margin. Base the performance
on the boiler burning fuels in accordance with the Coal Analysis [Fuel Oil Analysis] listed below.
a. Coal analysis
(1) Ultimate analysis (percent by weight)
Carbon [_____]
Hydrogen [_____]
Oxygen [_____]
Nitrogen [_____]
Sulfur [_____]
Ash [_____]
Moisture [_____]
TOTAL [_____]
(2) Proximate analysis (percent by weight)
Moisture [_____]
Volatile Matter [_____]
Fixed Carbon [_____]
Ash [_____]
TOTAL [_____]
(3) Coal characteristics:
Heating value: [_____] kJ/kg Btu/lb
Ash softening temperature reducing: [_____] degrees C F
Oxidizing: [_____] degrees C F
Free swelling index (coke button): [_____]
Size: 32 by 19 mm: [_____] percent; 19 by 6.35 mm: [_____] percent; 6.35 by 0 mm: [_____]
percentSize: 1 1/4 by 3/4 inch: [_____] percent; 3/4 by 1/4 inch: [_____] percent; 1/4 by
0 inch: [_____] percent
(4) Coal Variations: Due to periodic changes in coal suppliers, the boiler and stoker combination
shall be designed to burn any coal within the following limits (percent by weight unless indicated
otherwise):
Minimum Maximum
Ash [_____] [_____]
Sulfur [_____] [_____]
Hydrogen [_____] [_____]
Carbon [_____] [_____]
Moisture [_____] [_____]
Nitrogen [_____] [_____]
Oxygen [_____] [_____]
kJ per kg [_____] [_____]
Btu per pound [_____] [_____]
Ash softening temperature [_____] [_____]
Volatile matter [_____] [_____]
Fixed carbon [_____] [_____]
b. Fuel oil analysis
NOTE: Use Fuel Oil Analysis Schedule only when fuel oil burners are used.
Grade of fuel oil ultimate analysis (percent by weight)
Carbon: [_____]
Hydrogen: [_____]
Oxygen: [_____]
Nitrogen: [_____]
Sulfur: [_____]
Ash: [_____]
Moisture: [_____]
Total: [_____]
Heating value: [_____] kJ/kg Btu/lb
Specific gravity: [_____] degrees API
Viscosity at burner: [_____] SSF at 50 degrees C 122 degrees F
Water and sediment (by volume): [_____] percent
Flash point: [_____] degrees C F.
1.4.4.2 Oil/Burner Windbox Package
Burner turndown ratio on the specified fuel oil shall be not less than eight to one, with excess air not over
15 percent at full steam load, and excess air not over 22 percent at 20 percent steam load. [Air flow shall
be modulated through a single set of register louvers.]
1.4.4.3 Miscellaneous Equipment
a. Boiler feed pump service requirements:
(1) Capacity: [_____] L/s gpm
(2) Pumping temperature: [_____] degrees C F
(3) Liquid pH: [_____]
(4) Discharge head: [_____] kPa feet
(5) Available NPSH: [_____] kPa feet
(6) In addition to the operating point established above, the pump curve shall also run through
the following points:
Capacity Discharge Head
[_____] L/s [_____] kPa
[_____] L/s [_____] kPa
Capacity Discharge Head
[_____] gpm [_____] feet
[_____] gpm [_____] feet
b. Condensate pump service requirements
(1) Capacity: [_____] L/s gpm
(2) Pumping temperature range: [_____ to _____] degrees C F
(3) Liquid pH: [_____]
(4) Discharge head: [_____] kPa feet
(5) Available NPSH: [_____] kPa feet
(6) In addition to the operating point established above, the pump curve shall run through
the following points:
Capacity Discharge Head
[_____] L/s [_____] kPa
[_____] L/s [_____] kPa
Capacity Discharge Head
[_____] gpm [_____] feet
[_____] gpm [_____] feet
1.5 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are [for Contractor Quality Control approval.][for information only. When used, a designation following the
"G" designation identifies the office that will review the submittal for the Government.] The following shall
be submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-02 Shop Drawings
Boiler drawing
Boiler room auxiliary equipment
Stokers
Ash handling system
Burners
Dampers, stacks and breechings
Coal handling equipment
Fuel oil equipment
Piping and specialty items
Flexible ball expansion joint installation details
Reinforced concrete foundation
Reproducible drawings
Submit for approval within [60] [75] [90] days after award of contract. Drawing size shall
be A1 (841 by 594 mm) 34 by 22 inches.
SD-03 Product Data
Boiler
Boiler room auxiliary equipment
Stacks
Coal handling equipment
Insulation
Submit for approval within [60] [75] [90] days after award of contract.
SD-04 Samples
Each type of insulation
Include the intended application for each type of insulation and attach manufacturer's stamp
or label giving name of manufacturer, brand and description of material.
[SD-05 Design Data
NOTE: Choose this paragraph only if the paragraph entitled "Stacks With Flue
Gas Scrubbers, Boilers 5 kg/sec 40,000 lb/hour and over" and its subparagraphs
are chosen. Delete this paragraph if the paragraph entitled "Stacks With No
Flue Gas Scrubbers, Boilers 5 kg/sec 40,000 lb/hour & Under" and its subparagraphs
are chosen.
Stacks with flue gas scrubbers, boilers 5 kg/sec 40,000 lb/hour and over
Submit design calculations for static and dynamic analysis and damping. Submit manufacturer's
foundation and stack calculations. Submit as specified under paragraph entitled "Stacks With
Flue Gas Scrubbers, Boilers 5 kg/sec 40,000 lb/hour and Over."]
SD-06 Test Reports
Boiler predicted performance data
Fan performance data
Instrument air compressors
Variable speed motor controller
Submit certified copies of variable speed motor controller design, production and conformance
tests for approval before delivery of the equipment.
Steam heating plant
Submit for tests and inspections specified under paragraph entitled "Field Quality Control."
SD-07 Certificates
List of equipment manufacturers
Proof of experience
Submit the required information and experience certificates prior to commencing work on the
site.
System and equipment installation
Vertical fuel oil tank calibration
Backflow preventer
SD-10 Operation and Maintenance Data
Submit in accordance with Section 01 78 23 OPERATION AND MAINTENANCE DATA.
Equipment, Data Package 3
Control components, Data Package 4
Submit in accordance with Section 01 78 23 OPERATION AND MAINTENANCE DATA.
SD-11 Closeout Submittals
Posted Operating Instructions
1.6 QUALITY ASSURANCE
Equipment shall be factory assembled except for steam generators, coal handling equipment, and ash handling equipment
which shall utilize shop assembled components to the maximum extent to facilitate erection and minimize field
labor.
1.6.1 Standard Commercial Product
Boilers and equipment shall as a minimum, be in accordance with the requirements of this specification and shall
be the manufacturer's standard commercial product. Include additional or better features which are not specifically
prohibited by this specification, but which are a part of the manufacturer's standard commercial product in the
boilers and equipment being provided.
1.6.2 Equipment Furnished
Equipment furnished by the Contractor shall be furnished by the manufacturers listed.
1.6.3 Responsibility
The Contract drawings show the required general arrangement configuration and location of equipment items. However,
this contract allows selection of vendor's equipment, at the option of Contractor, provided that vendor's experience
and equipment meet requirements of these drawings and specifications. Because there may be significant variation
between the drawings and individual vendor's equipment as to foundations, physical dimensions and detailed arrangement
of these equipment items, the Contractor is required to furnish detailed design and shop drawings and calculations
for the systems selected. Foundation arrangements, walkways and other information as required shall be shown
for a completely coordinated, useable and properly functional system. A single system supplier shall be responsible
for a complete system including erection or erection supervision for each of the following systems:
a. Boiler system, including but not limited to the boiler, stoker, oil burners, [economizer,]
[air preheater,] refractories, insulation, induced draft fan, sootblowers, steam separator,
forced draft fan, overfire air fan, reinjection system, boiler trim, blowdown valves, safety
valves and trim, and breeching. System manufacturer shall coordinate required instrumentation
and control logic with controls and instrumentation supplier. Controls and instrumentation
are specified in VAMS Section 23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT.
b. Coal handling system, including but not limited to the track and reclaim hoppers, belt feeders,
belt conveyors and tube galleries, telescoping chute, flight conveyor, coal bunker, under bunker
conveyor with triple valves, coal scale and non-segregating distributor.
c. Ash handling system including clinker crusher, ash intakes, ash silo with baghouse filter,
vacuum pump and rotary dustless filter.
d. Stack system including steel stack, internal acid resistant lining and external coating.
e. Emission equipment including precipitator, scrubber and baghouse.
1.6.4 Certification of Backflow Preventer
Certificate of Full Approval or current Certificate of Approval for each backflow preventer being provided for
this project shall be from the Foundation for Cross-Connection Control Research, University of Southern California,
and shall attest that the design, size, and make of backflow preventer has satisfactorily passed the complete
sequence of performance testing and evaluation for the respective level of approval. A Certificate of Provisional
Approval will not be acceptable in lieu of the above.
1.6.5 Modification of References
In the API publications referred to in this paragraph, the advisory provisions shall be considered mandatory,
as though the word "shall" had been substituted for "should" and "suggested" wherever they appear.
1.6.6 Certificates
1.6.6.1 List of Equipment Manufacturers
Submit a letter which names the equipment manufacturers for the following equipment. When the Contracting Officer
determines that a manufacturer does not meet the qualification or experience requirements of the specifications,
the Contractor shall submit, to the Contracting Officer, the name of another manufacturer within fifteen days
of notification.
a. Boilers and stokers
b. Boiler feedwater pumps
c. Coal car handling equipment
d. Induced draft fans
e. Coal handling equipment
f. Ash handling equipment
1.6.6.2 Proof of Experience
Submit proof of experience of manufacturers, system suppliers and installers as follows:
a. Experience, Responsibility and Certification: Submit to the Contracting Officer, the required
information and experience certificates within 30 days after award and prior to commencing work
on the site.
NOTE: Verify number of manufacturers' installations operating and years of
operation for coal handling systems, ash handling systems and control systems
to avoid an unnecessarily restrictive experience requirement.
b. Experience Requirements: Boilers and equipment installed within or as a part of the heating
plant shall be of proven designs. Each manufacturer or system supplier shall be regularly engaged
in designing, fabricating, erecting or erection supervision, testing and starting up of the
equipment or system. Within 30 days after award or at any time during performance of the contract,
when the Contractor is required to use another manufacturer or system supplier is required through
no fault of the Contractor, the Contractor shall submit a certificate and other evidence from
each manufacturer or each system supplier to show that equipment and systems, made or furnished
by the manufacturers or system suppliers, have substantially comparable operating requirements
to the equipment or systems specified under this section and that they have been successfully
installed and reliably operated in at least [one] [two] [three] installations under substantially
comparable operating conditions for a period of not less than two years.
c. Information Required: Submit to the Contracting Officer, evidence or proof of experience
required from the equipment manufacturer or system supplier containing the following information:
(1) List of installations meeting the aforementioned requirements including detailed description
of equipment furnished for each one.
(2) Owner and location of each installation.
(3) Name and phone number of supervisory person at each installation.
(4) Date of Owner acceptance of such installation.
d. Vertical Fuel Oil Tank Calibration Experience: Submit to the Contracting Officer evidence
or proof that the tank calibration organization has at least 2 years of prior successful and
accurate experience in calibrating tanks of comparable type and size.
1.6.6.3 System and Equipment Installation
Submit from each system supplier and each manufacturer of the equipment, written certification that the system
and equipment installation is in accordance with the system supplier's and equipment manufacturer's instructions
and recommendations, that the unit or system has been run, rotating parts have been dynamically balanced, fluid
(including air) flows have been balanced, instrumentation and controls are properly functioning, adjusted and
have been calibrated, and the sub-system (or equipment) is ready for final testing, before entire boiler plant
may be given an acceptance test.
1.6.6.4 Vertical Fuel Oil Tank Calibration
Submit four copies of the certified record.
1.6.6.5 Backflow Preventer
Submit a Certificate of Full Approval or a current Certificate of Approval for each design, size, and make of
backflow preventer being provided for the project.
1.6.7 Posted Operating Instructions
Provide posted operating instructions for each piece of equipment installed.
1.6.8 Operation and Maintenance Data
Submit operation and maintenance data for each equipment, including control components. Include the following
supplemental information in addition to requirements of Section 23 03 00.00 20 BASIC MECHANCIAL MATERIALS AND
METHODS.
a. Illustrations, catalog information, shop drawings, and certified drawings of each item of
equipment and control components
b. Tests and test results
c. Adjustments
d. Fan and blower characteristics curves
e. Pump characteristic curves superimposed on system curves at various pumping rates (20, 40,
60, 80, 100 percent capacity)
f. Boiler predicted performance data
g. List of special tools required
1.7 DELIVERY, STORAGE AND HANDLING
1.7.1 Assembly of Components
Each assembly of components packaged as a unit shall be of the size that can be transported by common carrier
without disassembly insofar as shipping clearances are concerned.
1.7.2 Storing Tubes
Grind tube ends before shipment and properly coat against elements that may cause rusting or decomposition prior
to erection. Store tubes used in erection of boiler with full protection from elements and at no time shall
tubes be stored upon the ground. Maintain sufficient space between bottom row of tubes and ground to give good
circulation of air at all times. Before installing tubes, remove mill scale and other foreign matter.
1.8 ENVIRONMENTAL REQUIREMENTS
1.8.1 Air Permits
Permits for construction and operation of the boiler plant shall be obtained from the local environmental regulatory
agency prior to the start of construction.
1.8.2 Boiler Emissions
Comply with local, state, and federal emission regulations for the fuel to be fired.
1.8.3 Oil Burner/Windbox Package
The emission requirements shall be met at the maximum required continuous output. The burner shall meet environmental
rules and regulations. Emission requirements to be considered are oxides of nitrogen (NOx), opacity, particulates,
sulfur dioxide, and carbon monoxide. Compliance with NOx emission regulations shall be met using one [a combination]
of the following:
a. Low NOx burners
b. Flue gas recirculation
c. Other NOx reduction methods
1.9 EXTRA MATERIALS
a. Furnish two extra sets of air filters for each compressor.
NOTE: At the text below, choose one of the two following items in coordination
with the option chosen in Part 2 "Compressed Air Dessicant Air Dryer" or "Compressed
Air Refrigerated Air Dryer."
[b. Furnish 4 spare prefilters and 4 spare afterfilters for compressed air dessicant air dryer.]
[c. Furnish 4 spare disposable cartridge type prefilters and afterfilters each, for compressed
air refrigerated air dryer.]
d. Furnish a spare set of refractory bricks for each thawing unit.
PART 2 PRODUCTS
2.1 MATERIALS
Provide materials free of defects which would adversely affect the performance or maintainability of individual
components or of the overall assembly. Materials not specified herein shall be of the same quality used for
the intended purpose in commercial practice. Unless otherwise specified herein, equipment, material, and articles
incorporated in the work covered by this specification shall be new.
2.1.1 Identical Items
Provide physically and mechanically identical boilers and equipment of the same classification, size or capacity
to permit the interchangeability of replacement parts. This requirement includes parts, assemblies, components,
and accessories. Parts provided on the same type unit regardless of size and identifiable by identical part
number shall be functionally and dimensionally interchangeable. No deviation is acceptable without prior written
approval of the Contracting Officer.
2.2 [COAL/OIL] [COAL] FIRED BOILER
Multiple-drum, bent tube, field erected, cross drum, high static head, and vertical combustion chamber type designed
for stoker [and oil] firing. Stoker [and oil burner] shall be as specified elsewhere in this section. Utilize
shop assembled components to the maximum extent to facilitate erection and minimize field labor. Materials shall
be as specified herein. Materials and piping shall meet requirements of ASME BPVC SEC I. Boiler shall be
a fully erected water tube boiler, including engineering, labor, supervision, tools, materials, and testing required
for a complete operational unit. Equipment shall include boiler, waterwalls, refractories, insulation, supporting
structural steel, steel casing and lagging, windbox, ductwork, sootblowers, stoker, [oil burners], ASME required
safety valves, valves and trim, forced draft fan, induced draft fan and overfire air fan. Boiler design shall
be fully integrated with and coordinated with stoker, [fuel oil burner,] economizer, and forced draft fan, induced
draft fan, and controls specified elsewhere in this section. Boilers with [welded wall,] [or] [tube and tile]
are acceptable.
2.2.1 Operational Requirements
Boiler shall be capable of operating continuously at the maximum specified conditions without damage or deterioration
to boiler, settings, firing equipment or auxiliaries. Boiler shall be capable of automatically controlled operation
while burning specified fuel[s].
2.2.1.1 Furnace Heat Input
NOTE: See NAVFAC Design Manual DM-3.6, Table 12 Stoker Selection Criteria.
When boiler is operating at a maximum continuous rating, heat input to furnace shall not exceed either of the
following limits:
a. [310] [362] kW [30,000] [35,000] Btu per hour per cubic meter foot of furnace volume.
b. 315 kW 100,000 Btu per hour per square meter foot of effective radiant heating surface.
Combustion gas temperature at furnace exit shall not exceed [1149 degrees C2100 degrees F when firing oil and]
93 degrees C 200 degrees F below ash fusion temperature when firing coal.
2.2.2 Construction
2.2.2.1 Boiler Drums
NOTE: Boilers 11 1/4 kg of steam per second 90,000 pounds of steam per hour
or more should have a steam drum of not less than 1372 mm 54 inches in diameter
and a lower drum of not less than 1067 mm 42 inches in diameter.
Drums shall be steel plate, fusion welded in conformance with the ASME BPVC SEC I. The manufacturer shall determine
the inside diameter and overall length of each drum except that the steam drum shall be sized sufficiently large
to contain the steam-water separating equipment, to prevent excessive rise of water due to sudden change in steam
demand, and to allow for ready access into the drum. The steam drum shall be at least [_____] mm inches internal
diameter. The lower drum shall be at least [_____] mm inches internal diameter. Provide each drum with an elliptical
manhole at each end not less than 300 by 400 mm 12 by 16 inches, with hinged manhole cover, yoke and gaskets
and machined to fit manhole flange of head. Provide flat bar ring of not less than 10 gage steel plate welded
to the exterior of the drum heads around the manholes for protection of the drum head insulation. Rings shall
be continuous and shape shall conform to the general outline of the manhole opening. Groove the tube holes in
the drums for maximum holding power. Fusion weld the longitudinal seams in drums and the circumferential joints
between heads and shells. Remove excess welding material and clean drum surface. Relieve stresses caused by
welding by heat treatment in annealing furnaces, and X-ray the seams to ensure complete and proper welding.
Drum variation shall not exceed one percent between maximum and minimum diameters at any section and when necessary,
reheat, reroll or reform drums to meet this requirement.
a. No part of the boiler drum or header surface shall be directly exposed to furnace radiation
unless it is adequately protected by a water screen in such a manner that no part of the exposed
drum or header surface shall be more than 50 mm 2 inches from the nearest water tube.
b. Fit the steam outlet drum of the boiler with easily removable efficient dry pipe, special
baffle, or other separating device so that the steam delivered to the boiler header shall have
not more than 1.0 ppm of total solids at maximum continuous load, and during change of load
from 50 percent to 100 percent of continuous rated capacity within a three minute period, provided
that the total solids concentration in the boiler water does not exceed 3500 parts per million,
the total alkalinity concentration does not exceed 700 parts per million, and no organic matter
is present.
c. Nozzles for safety valves, main steam outlet, feed and blowdown lines, shall be forged steel,
straight neck type, flanged and fusion welded to drums. Weld threaded connections in the steam
drum for the feed water regulator, continuous blowdown, vent gage, and chemical feed lines.
d. Provide steam drum with internals for continuous blowdown, running the length of the steam
drum at the point of highest concentration of dissolved solids, and an internal distribution
pipe for chemical feed. Continuous blowdown and chemical feed pipe inside of drum shall be
stainless steel.
2.2.2.2 Headers
Horizontal lower and upper side wall headers shall preferably be square. However, round headers are acceptable,
provided approved stoker seals are provided. Provide rear wall and front wall headers. Protect the front wall
header by studs and pack with insulating cement. Provide headers with key caps or gasketed type handhole fittings.
2.2.2.3 Tubes
Boiler design pressure shall not be less than 1724 kPa (gage) 250 psig. Water tube rows and first two rows of
main boiler bank shall be one gage heavier than other tubes. Tubes shall be resistance welded or seamless, ASME BPVC SEC II-A
SA-178/SA-178M, Grade A carbon steel not less than 63.50 mm 2 1/2 inches O.D.; tubes shall not be reduced in
size at the boiler drums. Manufacturer shall indicate the size, weight, and kind of tubes on the submittal drawings.
Furnace walls and roof shall be water cooled. Radii of bends in tubes shall be such that standard turbine type
cleaners can easily pass through the full length of the tubes.
a. When a boiler is provided with welded wall construction, the tube side walls, front wall,
and furnace roof shall be of gastight construction, tubes shall be skin cased for gastight construction.
b. The width of the water wall tubes, as determined by the outside diameter of the tubes, shall
cover at least 50 percent of each of the front, rear furnace, side walls, and roof of the boiler.
c. Tube connections to upper drum shall be so arranged that the ends of downcomer tubes shall
be covered with water when the water level in the steam drum is 50 mm 2 inches below the bottom
of the gage glass with the gage glass being centered at the normal water level in the drum.
Tube bends shall be free of wrinkles and at no point of the bend shall the diameter of the tube
be more than 3 mm 1/8 inch less than the minimum allowable diameter of the tubes.
d. Space boiler and water wall tubes so that tubes may be removed and replaced without disturbing
another tube.
2.2.3 Boiler Setting and Insulation
Provide a complete setting including firebrick, refractory tile, insulation, tile supports, supporting steel,
steel casing, material for expansion joints, and necessary work and materials to provide a complete gas envelope
for the convector and water walls.
2.2.3.1 Expansion Joints
Provide expansion joints where required to permit brickwork to expand freely without interference with the boiler.
Joints shall be of adequate width, tightly sealed against leakage, and free from mortar, with the outer 100 mm
4 inches sealed with resilient material suitable for 927 to 1093 degrees C 1,700 to 2,000 degrees F. In addition,
to allow for expansion of the inner face, a series of 3 mm 1/8 inch wide vertical openings spaced 1.83 meters
6 feet apart shall be provided on the furnace side of the wall. Proper provision shall be made for expansion
and contraction between boiler foundation and floor.
2.2.3.2 Welded Wall
a. Inner Casing: Provide No. 10 gage inner casing for tangent tube construction.
b. Insulation and Firebrick: Back up the walls and roof of the furnace with not less than
63.50 mm 2 1/2 inches of block insulation (816 degrees C1500 degrees F class) or ASTM C 155
insulating firebrick. Provide standard welded casing or lagging to cover and protect insulation.
c. Furnace Roof Tube Openings: Where necessary, such as where the furnace roof tubes are separated
to enter the drum, the opening shall be completely inner cased and filled with ASTM C 401 castable
refractory.
2.2.3.3 Tube and Tile Furnace Construction
Sides, front and rear walls, and the roof of the boiler, as far as is practical, shall include water wall tubes
backed up with not less than a thickness of 63.50 mm 2 1/2 inches of super duty Class, regular type, ASTM C 27
fire brick followed by high temperature block insulation 816 degrees C 1500 degrees F Class or ASTM C 155 insulating
firebrick. Insulation shall not be less than 127 mm 5 inches thick on the furnace walls and roof, 100 mm 4 inches
thick on the side walls beyond the furnace, and 76 mm 3 inches thick on the rear wall, consisting of two layers
with staggered joints. Plaster the entire exterior of the setting with a thin coating of plastic high temperature
cement before the casing is applied.
2.2.3.4 Drum, Header and Miscellaneous Insulation
a. Drum Heads: Insulate drum heads with a minimum thickness of 51 mm 2 inches of calcium silicate
blocks applied in two 25 mm one inch layers with 25 mm one inch mesh wire fabric embedded between
layers. Entire surface shall be neatly finished with 13 mm 1/2 inch coat of smooth, hard finish
hydraulic setting insulating cement with one inch chicken wire mesh embedded therein. Neatly
finish drum heads with a field applied 0.47 kg 14 ounce per square meter yard glass cloth.
b. Drum Top and Header: Insulate the top half of the steam drum as previously specified for
drum heads, but finish with 16 gage welded steel casing. Provide insulation to the flange on
smoke outlet of the boiler. Insulate headers and downcomer tubes with not less than 38 mm 1
1/2 inch thick calcium silicate blocks banded in place, covered with 13 mm 1/2 inch thick coat
of hydraulic setting insulating cement and enclosed in an 18 gage metal lagging with openings
for access to handhole fittings, as required.
c. Miscellaneous: Provide special firebrick and tile required in connection with fitting of
doors and seals, and around stoker and headers. Build arches of wedge brick where arches are
required for door openings. Line doors exposed to furnace radiation for full depth of door
with plastic refractory properly fastened to door. Caulk expansion joints with temperature
resisting caulking material at points where setting joins parts of boiler. Provide air passages
in insulated walls or brick work required for the stoker.
2.2.3.5 Baffles
When provided, baffles shall be properly located and practically gastight. Maximum velocity at end of baffle
where gas turns shall be 17 meter 55 feet per second, except at baffle above rear pass hopper where maximum velocity
shall not exceed 12 meter 40 feet per second.
2.2.3.6 Casing
NOTE: Designer shall fill in this blank depending on type of air pollution
equipment and maximum pressure possible to be exerted on boiler casing by induced
draft fan. Do no use less than 4980 Pa 20 inches of water gage.
Provide the entire setting, other than the top half of the steam drum with a continuously welded tight skin steel
casing of not less than 10 gage, or an integral wall construction with outer casing of not less than 12 gage
construction. Weld other steel casing joints where practicable, and reduce the number of bolted joints to a
minimum. In places where sections of the casing are subject to removal periodically for inspection and maintenance,
the casing shall be bolted using 18 mm 5/8 inch bolts on not more than 76 mm 3 inch centers with joints gasketed.
Design the steel cased settings to withstand an internal negative or positive pressure of not less than the maximum
static pressure generated by the boiler fans at shutoff and test block, plus a 25 percent safety factor without
objectionable deflection of sides, or damage to side walls, casing, or refractory materials, or other parts of
the unit. The minimum design pressure shall be a [_____] Pa inch water column. Make proper provisions for expansion
and contraction of the casing without creating breakage or air leaks. With a surface wind velocity of 0.07 meter
2 feet per second, the average surface temperature of the casing shall not exceed 66 degrees C 150 degrees F
while the boiler is operated at full rated load in an ambient temperature of 38 degrees C 100 degrees F. Finish
the top half of the steam drum with 16 gage welded steel casing, as previously specified for the setting.
2.2.3.7 Access and Observation Doors
a. General: Provide boiler with a sufficient number of access and observation doors, to give
free and easy access and observation to parts of the interior of the boiler.
b. Access and Cleaning Doors: Provide a minimum of [_____] by 450 mm 18 inch access and cleaning
doors to give free and easy access to parts of the interior of the setting and the convection
section of boiler. Brick up the furnace access door openings with No. 1 firebrick or firebrick
tile properly held in place, between door and furnace.
NOTE: At the text below, consider that access is essential to all spaces between
boiler tube banks, the convection section, and on both sides of baffles within
these spaces. Consider access door under burner box when oil fired.
c. Observation Doors: Provide boiler with not less than [_____] by 250 mm 10 inch observation
doors and [_____] 100 by 100 mm 4 by 4 inch peep doors.
NOTE: At the text below, do not specify less than 8 observation doors and consider
using more when it is desired. On traveling grate stokers an observation door
should be located above each air zone on both sides of the boiler which will
probably result in using a greater number of observation doors.
d. Door and Opening Frames: Frames and front plates for openings for doors, soot blowers,
overfire air openings, and other such items, in the pressure parts shall be completely gastight
and airtight. Doors shall close against planed seats or the equivalent and shall be provided
with heavy latches. Anchor door frames securely. There shall be no air leaks between door
frames and setting.
2.2.3.8 Draft Connections
Provide draft connections through setting and steel casing for draft and airflow connections for combustion control
and metering. Provide draft connections for measuring furnace draft, boiler outlet gas pressure, [and] economizer
outlet gas pressure, [and fly ash collector outlet gas pressure]. Provide other openings as required for temperature
elements and other combustion control and metering items in accordance with ABMA Boiler 103, recommended standard
instrument connections unless otherwise specified.
Connection Minimum Size
Thru setting 50 mm
Flue gas 25 mm
Air ducts (windbox) 25 mm
Connection Minimum Size
Thru setting 2 inches
Flue gas 1 inch
Air ducts (windbox) 1 inch
2.2.4 Support and Framing
a. Support the boiler entirely independent of the casing and tile work, in a manner that will
allow for expansion and contraction without straining part of boiler or affecting the setting.
Support boiler and stoker entirely on structural steel work extending down to foundations as
indicated.
NOTE: At the text below, provisions must be made for adequate boiler foundations
based on soil conditions at each plant location. Foundations should be typically
detailed on the drawings.
b. Provide structural steel columns and beams to support the boiler [_____, _____] [and] [stoker]
[and the boiler operating floor adjacent to the boiler,] [walkways, and platforms] [as indicated].
Size steel to support the equipment dead loads imposed, plus a minimum live load of 976 kg 200
pounds per square meter foot.
NOTE: Designer should include here any provisions where boiler steel is to
serve as support for portions of building, or equipment.
[c. Boiler manufacturer shall furnish a drawing showing the magnitude and location of the loads
imposed by the equipment and structural steel on the building structural steel.]
d. Provide anchor bolt setting plans along with anchor bolts with nuts and sleeves that shall
be set in concrete for attachment in support of boiler and allied equipment. Provide bolts
and nuts as required for items furnished.
2.2.5 Boiler Hoppers
2.2.5.1 Rear Pass Hoppers
NOTE: Delete bracketed portions with cinder return (fly ash reinjection) when
a cinder return system will not be incorporated into the project.
Provide rear pass hoppers at the rear of the stoker or boiler setting. Construct hoppers of 6 mm 1/4 inch thick
welded steel plate as approved. Hoppers shall have minimum storage capacity based on 8 hours of operation at
full load with no cinder return (fly ash reinjection) and shall have 200 mm 8 inch diameter outlets with standard
flanges on the bottom of the hoppers. [Coordinate hoppers and hopper outlet flanges with overfire air-cinder
return reinjection system furnished by the stoker manufacturer.] Provide insulation and lagging for the hoppers
as specified for the boiler.
2.2.5.2 Plenum Chamber
Enclose the underside of the grates so as to form a plenum chamber and not permit any leakage of siftings onto
the floor. Provide this chamber with a single hopper complete with access door and supporting steel. Provide
manually operated double leaf stoker blast gates at duct connection to plenum chamber. Provide an 200 mm 8 inch
diameter outlet with standard flange on bottom of the hopper.
2.2.5.3 Ash Storage Hopper
Hopper is specified under paragraph entitled "Ash Handling Equipment" in this section.
2.2.6 Boiler Trim
Fittings, drain valves, drain piping, feed piping, pressure gages, feed valves, stop valves, check valves, safety
valves, and other appurtenances shall comply with the applicable requirements of the ASME Boiler and Pressure
Vessel Code. Components shall conform to the following:
2.2.6.1 Boiler Blowoff Valve
Provide flanged [Class 250 cast iron] [Class 300 cast steel] body, seatless, sliding plunger type valves mounted
in tandem at each boiler blowoff connection.
a. Steel gate, globe and angle valves: ASME B16.34.
b. Safety, relief, and safety relief valves: MIL-V-18436.
2.2.6.2 Steam Gage
NOTE: Select gage scale to operate within the middle third of the range.
Provide a 300 mm 12 inch diameter indicating steam gage with chromium plated trim and zero to [_____] kPa (gage)
psig scale. Gage shall be complete with syphon, valve, piping, and fittings to properly connect same. Gage
shall be flush mounted on a 368 mm 14 1/2 inch square by 5 mm 3/16 inch thick steel plate. Provide plugged tee
connection for connection to remote steam gage.
2.2.6.3 Water Column
Provide a safety water column with high and low water alarm suitable for the design pressure of the boiler.
Column shall be complete with three-chain-operated gage cocks, heavy duty inclined gage glass, and quick-closing
water gage valves having cross levers and chains operated from floor. Gage glass shall be readable from any
point directly below unit. Make connections to water column from boiler with extra strong steel pipe and forged
steel fittings. Provide crosses instead of tees or elbows, with screwed plugs in open ends. Terminate bottom
of water column and water column gage glass with plug-in type valves accessible from operating floor. Provide
plugged, screw-in type connections in water column piping to accommodate a remote level indicator. Provide gate
valves immediately below water column and gage glass. Provide a suitable lamp fixture to illuminate water column.
2.2.6.4 Safety Valves
Provide not less than [_____] cast steel or cast iron body high capacity safety valves to give a total steam
relieving capacity in accordance with the ASME BPVC SEC I requirements as to total boiler and water wall heating
surface. Valves shall be set with a set pressure of [_____] kPa (gage) psig, [_____ kPa (gage) psig] [,_____
kPa (gage) psig] [and kPa (gage) psig] respectively. Valves shall have flanged inlet and outlet connections.
2.2.6.5 Non-Return Valve
Provide a non-return valve on each boiler steam outlet. The valve shall be a stop check angle body valve, flanged,
Class 250 cast iron or Class 300 steel body with handwheel shutoff, pressure operated disc and external equalizer.
The assembly for manual operation shall be outside screw and yoke type.
2.2.6.6 Blowoff Connections
Bottom drum blowoff connection on boiler shall be [_____] mm inch diameter and extended to outside of setting
terminating with Class 250, tandem iron body, flanged blowoff valves, and shall be in accordance with
ASME BPVC SEC I, Art. PG-59. Boiler water wall blowoff connections and economizer inlet pipe blowoff shall be
40 mm 1 1/2 inch diameter and extended to outside of setting and equipped with same type valves. Provide stop
valves for water column blowoff connections.
2.2.6.7 Miscellaneous Stop Valves
Provide stop valves for each connection to boiler near boiler; include valves for soot blowers, chemical feed,
vent, continuous blowoff, and required drains.
2.2.6.8 Tube Cleaner
Provide one tube cleaner suitable for cleaning tubes of the boiler. Tube cleaner shall operate on water at 1034
kPa (gage) 150 psig pressure. Tube cleaner shall be complete with one motor, one wrench, one cutter head assembled,
one universal coupling for cutter head, two sets of cutters, two sets of cutter pins, one set of arm pins, one
set of keeper pins, one brush with a set of refills, one tool box, and two 15 meter 50 foot lengths of heavy
duty hose with 20 mm 3/4 inch diameter pipe connections.
2.2.6.9 Wrenches
Provide special wrenches required for proper maintenance of equipment.
2.2.7 Boiler Limit Interlocks
Provide applicable boiler limit interlocks required by FS F-B-2910 and connect to effect safety shutdown of the
stoker [and oil burners]. Interlocks shall be compatible with and integrated into the instrumentation system
as specified.
2.2.8 Sootblowers
Provide the boiler [and] [economizer] [and air preheaters] with a sootblowing system using [steam] [compressed
air] for removing the deposits of soot and fly ash from the heat transfer surfaces. Sufficient number of blower
elements shall be provided to adequately clean the heat transfer surfaces. Fixed position, multi-nozzle rotating
elements may be provided in applications where flue gas temperatures do not exceed 982 degrees C 1800 degrees
F. Retractable soot blowers shall be provided where flue gas temperatures exceed 982 degrees C 1800 degrees
F.
2.2.8.1 Fixed Position Soot Blowers (Steam)
Soot blowers shall be steam, fixed position, multi-nozzled, rotating, valve-in-head type with electric motor
operation to permit the proper cleaning of the heat transfer surfaces with cam operated valves arranged to automatically
open the steam valve through the proper arc of rotation. Cams shall be adjustable to give the proper operating
arc or shall be specifically designed for each location. Furnish and install soot blowers complete, including
valve-in-head blower heads, wall sleeve bushings, high temperature elements, low temperature elements, [_____]
volt, [_____] Hz., [_____] kW hp motor operators, hand operated drain valve, with drilled orifice and disc to
prevent tight shutoff, element supports, clamps, bolts, and other such items. Furnish necessary piping and valves
including drainlines, shut-off valves, piping supports and insulation. Weld soot blower piping and fittings.
No screwed piping or fittings will be permitted. Blower elements shall be carefully installed to avoid rubbing
on tubes which would cause eventual tube failure. Scavenging air connections from forced draft fan shall be
provided where required to protect blowers in non-blowing position. Provide a single control station containing
start and stop pushbuttons and necessary relays to control the motor operators.
2.2.8.2 Fixed Position Sootblowers (Air Puff)
Sootblowers shall be air puff type, fixed position, multi-nozzled rotating element type complete with air master
controller for each boiler, entirely air-operated and designed for controlled automatic sequential operation.
Units shall be operated in such a manner that air issues from the element in a series of sustained high pressure
puffs of approximately one second duration each. During each puff, the element shall be rotated through a predetermined
and measured short arc (17 1/2 degrees) by means of a ratchet mechanism in the sootblower head. Between each
puff, no air shall flow through the blowers and there shall be sufficient time for the system to be restored
to full pressure. When the blowing cycle has been completed, the controller shall automatically stop the sequence.
Provide sootblowers complete with wall sleeve bushings, element supports, clamps bolts and other required components.
Provide necessary piping and valves, including shutoff valves, piping and supports. Weld sootblower piping and
fittings. No screwed piping or fittings will be permitted. Carefully install blower elements to avoid rubbing
on tubes which would cause eventual tube failure.
2.2.8.3 Retractable Sootblowers
Provide in lieu of fixed position type and where flue gas temperatures exceed 982 degrees C 1800 degrees F.
Sootblowers shall be [air] [electric] motor operated. Rotation of the blower shall be continuous from the moment
the lance begins to extend. Rotating and traversing speeds shall be independently adjustable by changing sprockets.
Blowers shall be complete with heavy steel housing, outside adjustment of nozzle pressure, alloy lance, wall
sleeve, supports, and other necessary appurtenances required for a completely workable system.
2.2.8.4 Elements
Equip units with elements specially designed for use with [steam] [air]. Elements subjected to temperatures
of 482 to 816 degrees C 900 to 1500 degrees F shall be chromium covered extra heavy carbon steel tubing or a
chrome alloy as specified for a higher temperature; between 817 to 927 degrees C 1501 to 1700 degrees F, they
shall contain not less than 20 to 23 percent chrome; from 928 to 982 degrees C 1701 to 1800 degrees F, not less
than 24 to 27 percent chrome. Provide a flexible connection between each head and element.
2.2.8.5 Control
On the operating floor provide a pushbutton for each boiler for starting and stopping system.
2.2.8.6 Control for Sootblowing System
Provide sootblowing system with an automatic programmable control system which will automatically start and stop
each sootblower in programmable sequence and monitor and display operation of sootblowers. Provide an overriding
control which will permit manual start-stop operation of sootblowers.
2.3 ECONOMIZER
Provide economizer [separate from the boiler] [integral to and within the boiler setting]. Economizer shall
be of the [bare tube] [cast iron fin covered steel tube] design complete with feedwater piping between economizer
and boiler drum. Economizer shall be constructed in accordance with the requirements of ASME BPVC SEC I meeting
the design and operating conditions as specified for the boiler and bearing the ASME Code symbol stamp. Economizer
shall be suitable for the operating conditions and the fuels specified. Materials provided shall withstand temperatures
and pressures prevailing under maximum load conditions. Economizer casing, insulation, and lagging shall be
specified for the boiler.
2.3.1 Accessories
Provide the following accessories and equipment for each economizer.
a. Sootblowers of the same manufacturer and construction as sootblowers to be provided for
boilers;
b. Stack temperature control with sensor and motorized feedwater temperature control valves
to function to limit flue gas temperature to a minimum of [_____] degrees C F by modulating
feedwater to the bypass;
c. Temperature and pressure indicators on feedwater outlet;
d. Temperature and pressure indicator on feedwater inlet;
e. Temperature and pressure indicator on flue gas outlet;
f. Temperature and pressure indicator on flue gas inlet;
g. Manual shutoff and bypass piping and valving;
h. Low point drain pipe complete with two blowoff valves as specified for the boiler; and
i. Audible alarm with silencing switch and indicating lights for high feedwater exit temperature,
low feedwater exit temperatures, low or high flue gas exit temperature, low feedwater entrance
temperature or pressure.
2.4 COAL GRATE STOKERS
NOTE: Choose from either the paragraphs and subparagraphs below entitled "Traveling
Grate Coal Stoker" or the paragraphs and subparagraphs entitled "Traveling Grate
Spreader Coal Stoker" that follow it.
[2.4.1 Traveling Grate Coal Stoker
NOTE: Designer shall select type of stoker most suited for each project. Stoker
Selection Criteria is shown in NAVFAC Design Manual DM-3.6, Table 12.
NOTE: When the boiler is not part of this project insert Coal Analysis at end
of this paragraph.
Stoker shall be of the bar and key traveling grate type arranged for rear ash discharge. Stoker shall be capable
of continuous operation at such rate as required for the continuous output of not less than that specified for
the boiler and shall satisfactorily provide for automatic operation, by means of combustion control system, within
the range given when burning the specified coal and operated in accordance with instructions supplied by the
manufacturer. Obtain satisfactory operating conditions throughout the full operating range of the stoker. The
stoker shall be considered as an integral part of the steam generator and shall be subject to applicable provisions
of the boiler design and service conditions together with requirements of tests, performance guarantees and other
warranties specified for the boiler. Coal analysis shall be as specified in the Coal Analysis Schedule for the
boiler. The gate moving mechanism shall be positive, up and down, and equipped with suitable operating mechanism
for manual control. Provide an indicator to show the vertical position of the gate and the thickness of the
fuel bed.
2.4.1.1 Stoker Grate Heat Release Rate
NOTE: Normally the stoker grate heat release will be 1417 kW per square meter
450,000 Btu per square foot per hour when coal meeting the criteria set out
in the Stoker Selection Criteria shown in NAVFAC Design Manual DM-3.6, Table
12 is used. When coal is specified which does not meet this criteria then the
grate heat release will have to be lowered accordingly.
Not greater than [_____] kW per square meter Btu per square foot per hour at the specified maximum continuous
rating for the boiler. The square meter feet of projected grate area shall be the product of the length measured
between the inside of the coal gate and the centerline of the rear shaft or return bend and the width of the
grate.
2.4.1.2 Construction
a. Fuel Feed Control: Control fuel feed to the stoker by the stoker speed and the vertical
position of the coal regulating gate. Coal gate to vary the thickness of the fuel bed shall
be of heavy cast iron with refractory facing to protect it from the furnace heat. The gate
moving mechanism shall be positive, up and down, and equipped with suitable operating position
of the gate and the thickness of the fuel bed.
b. Coal Hopper: Provide a coal hopper of 6 mm 1/4 inch thick Type 304 or 316 stainless steel
plate at the front of each stoker. The capacity of the hoppers shall not be less than [_____]
cubic meters feet.
c. Stoker Front Enclosure: Provide stoker fronts with dust tight enclosures of not less than
10 gage plate to eliminate dust from the boiler room and prevent air infiltration to the grate.
Fit these fronts with access doors.
d. Air Plenum (Siftings Hopper) and Ducts: Provide an undergrate air plenum and air ducts
for the stoker which will receive air from the forced draft fan. Plenum and air ducts shall
be not less than 10 gage steel plate. Provide concrete ducts or airways along the sides of
the setting when adaptable to use by the stoker submitted. Provide ducts in accordance with
drawings and requirements furnished by the stoker manufacturer. Provide unit with necessary
observation doors or ports of the self-closing glass-covered type for side walls, including
a minimum of four for observing the underside of the grate.
e. Stoker Air Zones: The stokers shall have not less than [_____] air zones with individual
control to each zone in order to provide optimum control of combustion conditions for loads
within the specified range and shall be so arranged that a positive air seal will be formed
between each zone. Design the zones to provide removal of siftings. To ensure proper air distribution
to each zone, provide an air control valve or damper for each zone. Control valves or dampers
shall be hand controlled and shall be accessible for instant adjustment by the operator from
the side of the stoker. Provide each zone with a pipe opening for a draft gage connection and
provide connection in the overfire air duct for the same purpose.
f. Stoker Grate: Mount the traveling grate stoker grate keys (clips) on carrier bars supported
from an endless heat treated type steel chain. Provide wearing shoes on the carrier bars to
carry the grate weight on skid rails extending the length of the furnace. The chain links
shall mesh with the shaft sprockets transmitting the driving force to the endless chain. Grate
keys (clips) shall be chrome alloyed cast iron to resist growth. Links shall be uniform. Grates
shall be made of the best quality, heavy duty, heat resisting, cast iron or cast alloy carefully
cast to minimize initial strain. The sifting hoppers and removal system shall be so arranged
that siftings may be removed from zones.
g. Grate Thermocouples: Provide two grate temperature sensing thermocouple arrangements on
each grate to indicate and record grate temperatures on the operator's [interface console] [control
panel].
h. Tension Adjustment: Provide a conveniently located adjustment accessible from outside of
the boiler or through access plates in the stoker front cover for regulating the tension of
the grate. Provide adequate adjustment for the chain length.
i. Stoker Seals: Provide the stoker with seals between the bottom of the sidewall header and
the frame. Provide restraints in the boiler setting to prevent seals at rear of stoker from
opening up.
j. Stoker Support: Stoker and drive shall be complete with supporting structural steel framework.
Locate and protect structural supports so that they will not be overheated or damaged by heat
from either the furnace or ash pit.
k. Grate Return Run Support: Adequately support the lower return run of the grate on a system
of cross members and longitudinal members or skids. Provide an air seal between this lower
drag frame and ash pit and siftings hopper.
2.4.1.3 Grate Ash Discharge Enclosure
Enclose rear end of grate, where ash is discharged into the hopper below the floor line, with a dust tight enclosure
made of heavy steel plates properly protected with fire brick where exposed to the furnace. Fit vertical ends
of this enclosure with cast iron, refractory lined inspection and access doors, one for each feeder. Seal off
roof of this enclosure with refractory, protecting metal parts from the furnace temperature with refractory.
Exposed metal parts in the enclosure are not acceptable. Enclosure shall be compatible with the ash storage
hopper as specified under paragraph entitled "Ash Handling System" this section.
2.4.1.4 Stoker Grate Drive
Drive the grate of the stoker through hydraulic drive, or with electrical motor and transmission equipment as
specified below. Drive shall have a variable speed ratio of not less than six to one with the speed changing
device, controlled automatically by the combustion control system. Provide a manual and reversing adjustment
so the grate speed can be operated independent of the combustion control system. Provide adequate safety release
to prevent damage to the drive or grates due to foreign material or jamming of the grates. Provide the front
and rear shafts of the grates with an adequate lubrication system with fittings located on the outside of the
setting.
a. Electric Motor: Motor shall be [_____] volt, [_____] phase, [_____] rpm, 60 Hz, totally
enclosed, fan cooled, not less than [_____] kW hp as specified under paragraph entitled "Motors
and Drives" in this section.
b. Mechanical Drive: Mechanical drive shall include variable speed transmission with gears
and chains, enclosed in an oil tight case, and running in a bath of oil. Bearings shall be
of the anti-friction type, with hardened inner and outer races and fitted with forced lubrication
fittings.
c. Hydraulic Drive: Hydraulic drive shall include a complete hydraulic system with adequately
sized reservoir, dual pumps, oil piping to and from drive, control and isolating valves, oil
cooler, when required, with self-operated cooling water control valve, oil temperature indicator,
and other accessories for a complete, satisfactory operating system.
2.4.1.5 Miscellaneous Equipment
Provide shafting, couplings, bearings, drives with guards, linkages, rods, and other miscellaneous equipment
from the stoker manufacturer required or necessary for interconnecting of the stoker units and drives necessary
for a complete operating system. Provide equipment even though it is not specifically mentioned herein. Gears,
chains, belts, couplings, and other moving parts shall be properly enclosed or guarded.
2.4.1.6 Lubrication
The entire stoker mechanism shall have adequate provisions for proper lubrication where required and shall be
equipped with conveniently located fittings for this purpose.
2.4.1.7 Overfire Air System
Provide an overfire air system from the stoker manufacturer to ensure good ignition at the stoker front and adequate
control of smoking. System shall include necessary nozzles, ducts, and overfire air fan with motor drive.
When more than one row of nozzles is supplied, provide individual air volume control for each row or set as required.
Locate nozzles or protect them with shields so as to prevent plugging of the nozzles in service. Nozzles shall
be constructed of materials suitable for service at maximum temperatures anticipated. Provide necessary arrangements
to the water wall tubes, arch construction, refractory, insulation, and casing from the boiler manufacturer,
to permit installation of an adequate overfire air system. Overfire system shall be capable of providing a minimum
of 15 percent of total combustion air at the required static pressure.
][2.4.2 Traveling Grate Spreader Coal Stoker
NOTE: Choose this paragraph and its subparagraphs or the paragraphs and subparagraphs
above, entitled "Traveling Grate Coal Stoker."
NOTE: When the boiler is not part of this project insert Coal Analysis at end
of this paragraph.
Stoker shall be of the overfeed, synchronized, self-feeding, spreader stoker type with continuous cleaning forward
moving bar and key grates suitable for burning a portion of the coal in suspension and burning the balance on
the grates. Stoker shall be capable of continuous operation at such rate as required for the continuous output
of not less than that specified for the boiler, and shall satisfactorily provide for automatic operation by means
of the combustion control system, within the range given when burning the specified coal and operated in accordance
with instructions supplied by the manufacturer. Stoker shall be considered an integral part of the steam generator
and shall be subject to all applicable provisions of the boiler design and service conditions together with requirements
of tests, performance guarantees and other warranties specified for the boiler. Coal analysis shall be [as specified
in the Coal Analysis Schedule for the boiler] [as listed below].
2.4.2.1 Stoker Grate Heat Release
NOTE: Normally the stoker grate heat release will be 2205 kW per square meter
700,000 Btu per square foot per hour when coal meeting the criteria set out
in the Stoker Selection Criteria shown in NAVFAC Design Manual DM-3.6, Table
12 is used. When coal is specified which does not meet this criteria then the
grate heat release will have to be lowered accordingly.
The active grate area shall be such that the heat release at the maximum continuous rating shall not exceed [_____]
kW per square meter Btu per hour per square foot. At minimum boiler rating the stoker grate heat release shall
be a minimum of [2280] [2850] MJ per square meter [200,000] [250,000] Btu per square foot; this results in a
guaranteed turndown ratio of [_____] to 1. Grate area shall be the product of the width between the inside faces
of the sidewall heaters at the grate line and the length of the air-supplied grate area. The grate shape shall
be designed so that the heat release per front meter foot of stoker width does not exceed 2930 kW 10,000,000
Btu/hour at the maximum continuous boiler rating.
2.4.2.2 Construction
a. Fuel Feed Control: Coal shall be fed to and distributed in the furnace by not less than
three overfeed type spreader stoker feeders for each boiler. Feeders shall be operated simultaneously
and at synchronized speeds so that any one feeder may be taken out of service without affecting
the operation of the others. Each feeder shall be readily adjustable to ensure proper fuel
distribution within the furnace. Design and size the total combined width of the feeder openings
for proper distribution of the fuel over the width of the stoker grate. Design shall be such
that the combined width of the feeders shall not be less than 40 percent of the width of the
stoker grate. The feeders shall be capable of handling and uniformly distributing coal varying
in size from 6 to 32 mm 1/4 to 1 1/4 inches with no more than 40 percent passing a 6 mm 1/4
inch round mesh over the entire grate area. The feeder shall be capable of properly performing
with moisture in the fuel as high as 15 percent by weight. Materials of construction shall
be such that coal with high sulfur content can be satisfactorily used without extensive corrosion
over the lifetime of the parts. Provide moving parts of the feeders with anti-friction type
bearings and with a forced system of lubrication. Bearings subject to high temperatures shall
be water cooled. Gear teeth shall be machine cut.
b. Coal Hopper: Provide a metal hopper for each spreader stoker feeder. Hoppers shall be
not less than 6 mm 1/4 inch thick 304 stainless steel plate, rigidly reinforced and connected
to the coal grates. Support hoppers from the floor or boiler columns to eliminate weight on
the feeders. Provide hoppers with suitable cleanout doors located in the front.
c. Air Plenum (Siftings Hopper) and Ducts: The traveling grate/stoker shall be complete with
under grate air plenum, manually operated blast gates and operating handles, and siftings hopper.
Plenum and air ducts shall be not less than 10 gage steel plate. Locate and protect structural
supports so that they will not be overheated or damaged by heat from either the furnace or ash
pit. Provide unit with necessary observation doors or ports of the self-closing glass-covered
type for side walls, including a minimum of four for observing the underside of the grate.
d. Stoker Grate: Grates shall be made of the best quality, heavy duty, heat resisting, cast
iron or cast alloy carefully cast to minimize initial strain. Specially design the grates for
spreader stoker firing. Grates shall be of high resistance, air metering type with closely
and uniformly spaced self-cleaning air openings. The grates shall have close fitting, overlapping
edges to prevent air leakage at the joints. Provide undergrate air seals at both the front
and rear ends fabricated of cast iron and counterweighted so that they will always be in close
contact with the under sides of the grates. Construct the rear seal to proportion the air flow
through the rear end of the grate to expedite coking and ignition of the coal, thereby properly
conditioning it for efficient combustion when the fuel bed reaches the active air admitting
area. Side seals between edge of stoker grate and boiler shall be approved bellows type.
e. Grate Thermocouples: Provide two grate temperature sensing thermocouple arrangements on
each grate to indicate and record grate temperatures on the operator's [interface console] [control
panel].
f. Tension Adjustment: Provide a conveniently located adjustment accessible from outside of
the boiler or through access plates in the stoker front cover for regulating the tension of
the grate. Provide adequate adjustment for the chain length.
g. Stoker Support: Stoker and drive shall be complete with supporting structural steel framework.
Locate and protect structural supports so that they will not be overheated or damaged by heat
from either the furnace or ash pit.
2.4.2.3 Grate Ash Discharge Enclosure
Enclose front end of grate, where ash is discharged into the hopper below the floor line, with a dust tight enclosure
made of heavy steel plates properly protected with fire brick where exposed to the furnace. Fit vertical fronts
of this enclosure with cast iron, refractory lined inspection and access doors, one for each feeder. Seal off
roof of this enclosure with refractory, protecting the metal parts from the furnace temperature with refractory.
Exposed metal parts in the enclosure are not acceptable. Enclosure shall be compatible with the ash storage
hopper as specified under "Ash Handling System" this section.
2.4.2.4 Feeder Drives
At the option of the Contractor, the drives shall be either individually driven and controlled feeders or feeders
driven by a line shaft with individual clutch arrangements.
a. Controlled Feeders: The individually driven and controlled feeders shall have a variable
speed drive on each distributor and a silicon controlled rectifier (SCR) D.C. motor drive for
each drum or feed box. A master controller shall receive a fuel demand signal from the combustion
control system and control the individual slave controllers of the individual SCR units to satisfy
the particular fuel demand. Control arrangement shall provide for simple adjustments between
feeders for equal fuel delivery and also for single feeder biasing.
b. Line Shaft Feeder: The feeders driven by a line shaft shall be driven through a variable
speed drive having a ratio of not less than three to one. Feeder drive shall be so arranged
that each feeder is independently driven from a lineshaft so that any feeder can be engaged
or disengaged without disturbing the operation of the remaining feeders. Fuel delivery shall
be governed by the combustion control system.
c. For either stoker drive system, provide a complete operating unit with necessary shafting,
couplings, bearings, drives with guards, linkages, rods, and other equipment, as required or
necessary for any interconnecting of the stoker units and drives. This equipment shall be provided
even though it is not specifically mentioned. Provide safety release to prevent damage to
the units due to foreign materials in the coal or other causes of overload.
d. Distributor: The distributor shall be driven by a variable speed electric drive which is
manually adjusted to achieve optimum distribution.
2.4.2.5 Stoker Grate Drive
Drive the grate the stoker by [hydraulic package] [electrical motor] [a steam turbine] through a variable speed
device with a speed ratio of at least six to one, with the speed changing device, controlled automatically by
the combustion control system. Provide a manual adjustment to regulate grate speed ratio to fuel feed in order
to compensate for variations in the ash content. Provide a suitable safety release device to prevent damage
to the drive or grates due to foreign material or other obstruction interfering with the grate operation.
NOTE: Make heat balance to determine whether it is more economical to use turbine
drives rather than electric motors.
a. Electric Motor: Motor shall be [_____] volt, [_____] phase, [_____] rpm, 60 Hz, totally
enclosed, fan cooled, not less than [_____] kW hp as specified under paragraph entitled "Motors
and Drives" in this section.
b. Steam Turbines: Drive shall be by steam turbine conforming to NEMA SM 23 as modified below.
Turbine shall be noncondensing capable of producing braking power [_____] kW horsepower at [_____]
rpm at a steam rate of not more than [_____] kg pounds per brake power hour. Inlet steam condition,
upstream of built-in governor, shall be [_____] kPa (gage) psig and [_____] degrees C F. Exhaust
steam conditions at exhaust nozzle shall be [_____] kPa (gage) psig. Turbine rotation shall
be [clockwise] [counterclockwise] and shall be [direct connected] [geared] to the driven piece
of equipment which shall operate at [_____] rpm. Piping connections 50 mm 2 inches and smaller
shall be screwed. Connections 65 mm 2 1/2 inches and larger shall be flanged. Inlet flanges
shall be raised face suitable for the inlet pressure specified. Exhaust flanges shall be Class
125 or Class 150 flat-faced flanges. Turbine shall be complete with insulation and lagging.
Insulation shall be as specified in Section 23 07 00 MECHANICAL INSULATION. Turbine governor
shall be of direct oil relay type with 10 percent adjustable speed range. Lubrication shall
be of the manufacturer's standard non-pressure type.
[c. Mechanical Drive: Mechanical drive shall include variable speed transmission with gears,
worm drives and bearings, enclosed in an oil tight case, and running in a bath of oil. Bearings
shall be of the anti-friction type, with hardened inner and outer races and fitted with forced
lubrication fittings.]
[d. Hydraulic Drive: Hydraulic drive when required shall include a complete hydraulic system
with adequately sized reservoir, dual pumps, oil piping to and from drive, control and isolating
valves, oil cooler, when required, with self-operated cooling water control valve, oil temperature
indicator, and other accessories for a complete, operating system. Hydraulic drive system motor,
shall be [_____] volt, [_____] phase, 1200 rpm, 60 Hz totally enclosed, fan cooled, not less
than [_____] kW hp as specified under paragraph entitled "Motors and Drives" in this section.]
e. Miscellaneous Equipment: For a stoker drive system, provide a complete operating unit with
necessary shafting, couplings, bearings, drives with guards, linkages, rods, and other equipment,
as required or necessary for any interconnecting of the stoker units and drives. This equipment
shall be provided even though it is not specifically mentioned herein. The front and rear shafts
of the grate are to be fitted with a forced system of lubrication with fittings located on the
outside of the setting. The devices for changing the speed ratio of the grate drives shall
be connected to the fuel feed regulation system, so both fuel feed and grate speed can be synchronized
and controlled automatically by the combustion control system. A manual adjustment shall be
provided to regulate grate speed ratio to fuel feed in order to compensate for variations in
ash content of the fuel. A suitable safety release device shall be provided to prevent damage
to the drives or grates, due to foreign material or other obstruction interfering with the grate
operation. Gears, chains, belts, couplings, and other moving parts shall be properly enclosed
or guarded.
2.4.2.6 Overfire Air System
NOTE: Designer should include bracketed sentence when cinder return (fly ash
reinjection) will not be incorporated in the project.
Provide a high pressure overfire air system for each stoker, including fan, [motor drive,] ductwork, dampers
and nozzles. The fan shall have a capacity of not less than 15 percent of the total air required at maximum
steaming capacity when operating at the predicted amount of excess air in the furnace. Static pressure of the
fan shall be sufficient to ensure full penetration of the furnace by the air jets, but not less than 6225 Pa
25 inches of water. Overfire air distribution nozzles shall be fabricated from heat resistant alloy. Locate
air jets properly and in sufficient numbers to create proper furnace turbulence for complete combustion at all
ratings. Make modifications and additions to the system to ensure penetration and turbulence of areas of the
furnace as required after startup. [There will be no cinder return system incorporated in the overfire air system.]
NOTE: At the text below, delete the following paragraph on pneumatic cinder
return (fly ash reinjection) system when this system will not be incorporated
in the project.
[a. Cinder Return System (Fly Ash Reinjection): Provide a pneumatic cinder return system to
reinject collected fly ash and unburned combustibles into the furnace. The system shall operate
in conjunction with the overfire air system and shall be complete with necessary air lines,
nozzles, ducts, and dampers for returning the cinders from the rear convection pass hopper of
the boiler and the economizer soot hopper or air heater hopper. Cinder return lines, shall
be constructed of abrasion-resistant iron having a Brinnell hardness of not less than 350, with
the exception that the straight conveyor lines, starting at a point not less than 600 mm 2 feet
downstream from each cinder pickup nozzle or elbow extending to within not less than 600 mm
2 feet of the furnace, may be constructed of extra strong Schedule 80 steel pipe. Provide
glass viewing ports at the end of each cinder return line so that interior of lines are visible
all the way through to furnace.]
]2.5 OIL BURNER/WINDBOX PACKAGE
NOTE: Choose this paragraph and its subparagraphs when oil is used.
NOTE: The designer shall fill in the appropriate information as defined in
FS F-B-2910.
Provide a fully modulating, oil burner conforming to FS F-B-2910 Rev F, Class [_____], except as modified below.
Provide burner with windbox, forced draft fan, dampers, fuel train and associated controls to comprise a complete
factory assembled package. Total heat input to boiler furnace shall be provided by [_____] burners. Burner
package shall be considered an integral part of the steam generator and shall be subject to applicable provisions
of the boiler design and service together with requirement of tests, performance guarantees and other warranties
specified for the boiler.
2.5.1 Burner
2.5.1.1 Burner Characteristics
The burner shall be quiet in operation and operate with a balanced clean, stable flame so as not to localize
heat in any part of the combustion chamber. Burner shall be capable of completely atomizing and effectively
mixing oil with air so as to ensure complete combustion. Air admitted shall be of sufficient quantity for complete
combustion, but not of such quantity as to produce an undue percentage of excess air with high stack loss. Oil
burner shall operate without clogging and shall have sufficient capacity to develop not less than the specified
capacity. Burner unit shall be easily removed from firing position and readily accessible for inspection, cleaning
and other purposes. Provide adequate observation ports on burner. Burner manufacturer shall guarantee that
there will be no flame impingement on sidewalls, top, bottom, or rear walls of furnace. Burner manufacturer
shall furnish, and contractor shall install refractory throat tiles or other items required for proper installation
of burner.
2.5.1.2 Atomization
NOTE: Burners may be air atomizing or steam atomizing. When a separate compressed
air system is used the designer shall fill in blanks with the quantity and pressure
of compressed air that will be available for fuel oil atomization. The designer
should allow for an adequate amount of atomizing air. Atomizing air requirements
will vary depending on many factors including burner design, fuel oil characteristics,
fuel oil pressure, air pressure and even furnace conditions. See NAVFAC Design
Manual DM-3.6 for empirical information.
Burner shall be [steam atomizing; steam pressure at header is [_____] kPa (gage) psig; steam temperature at header
is [_____] degree C F] [air atomizing; filtered compressed air shall be available for burner atomization and
the maximum requirement for each burner shall not exceed [_____] L/s scfm of air at [_____] kPa (gage) psig].
Provide pressure reducing valve and controls as required.
2.5.1.3 Electric Ignition System
Burner shall be equipped with an electric ignition system. System shall be either the high energy ignition or
glow rod type. Gas ignition system is not acceptable. The high energy ignition system shall use stored energy
to develop 2000 Vdc pulses. The glow rod system shall use a low voltage, carbon rod electrode which develops
a tip temperature of 1427 degrees C 2600 degrees F. Provide ignition system complete in all respects.
2.5.1.4 Windbox
Construct of carbon steel plate not less than 10 gage thickness with 6 mm 1/4 inch thick front plate. Design
windbox to provide even and uniform air entrance into the burner register and seal weld to the boiler front wall.
Provide windbox with support legs.
2.5.1.5 Purge Connection
Provide [steam] [air] purge connection, properly valved, for purging oil from gun prior to removal from burner.
2.5.1.6 Aspirating System
NOTE: Provide aspirating system only for boilers in which the expected furnace
pressure exceeds 1245 Pa 5 inches water.
Provide an air aspirating system for the fuel oil atomizer guide pipes to prevent blowback of hot furnace gases.
Aspirating system shall use approximately [_____] L/s scfm of [_____] kPa (gage) psig compressed air.
2.5.1.7 Guide Pipe Purge
Provide piping and flexible hoses for the guide pipe purge and aspirating systems. Air from the forced draft
fan shall be provided for guide pipe purging during normal operation.
2.5.1.8 Metal Parts
Metal parts exposed to radiant heat, including the atomizer shield, shall be of stainless steel or other approved
alloy.
2.5.1.9 Fuel Oil Control Valve
Fuel oil will be supplied at [_____] kPa (gage) psig and [_____] degrees C F at the inlet of the fuel piping
train. Size fuel oil automatic control valve for 103 kPa 15 psi differential pressure as specified in VAMS Section
23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT.
2.5.1.10 Fuel
ASTM D 396, Grade no. [_____].
2.5.1.11 Forced Draft Fan
NOTE: The designer shall make a technical evaluation to determine when the
forced draft fan should be integrated with or mounted separately from the windbox
on the floor next to the boiler. When the forced draft fan is to be mounted
separately, delete this paragraph and specify the fan in paragraph entitled
"FANS."
Fan shall be fully integrated with and mounted on the windbox. Provide an inlet silencer, when required, to
ensure operation at noise level below 85 dBA as specified in Section 22 05 48.00 20 MECHANICAL SOUND VIBRATION
AND SEISMIC CONTROL.
2.5.1.12 Electric Motor
NOTE: The designer shall perform an economic analysis and make a technical
evaluation to determine when forced draft fan motor shall be provided with variable
speed control. Generally, variable speed drives for forced draft fans over
7 1/2 kW 10 hp will be cost effective.
Motor shall be [variable speed], [_____] volt, [_____] phase, 60 Hz, [totally enclosed, fan cooled], [totally
enclosed, non-ventilated], not less than [_____] kW hp as specified under paragraph entitled "Motors and Drives"
in this section.
2.5.2 Flame Safeguard Controls
Provide a complete system of valves, interlocks and controls in accordance with NFPA 85 and as approved by Factory
Mutual Engineering and Research.
2.5.2.1 Fuel Oil Train
Provide fuel oil train consisting of [steam] [air] atomizing oil gun, auxiliary [steam] [air] atomizing oil gun
for changing guns without a shutdown, fuel oil control valve, two safety shutoff valves recirculation valve,
strainer, and flexible hose connections to oil burner package the following gages. Gages shall be 150 mm 6 inch
with white coated dials and black figures:
a. Fuel oil supply pressure (0 to 1034 kPa (gage) 150 psig)
b. Fuel oil pressure at burner (0 to 1034 kPa (gage) 150 psig)
[c. Atomizing air pressure at burner (0 to 1034 kPa (gage) 150 psig)]
[d. Atomizing steam pressure at burner (0 to 1034 kPa (gage) 150 psig)].
2.5.2.2 Control Sequencing
Flame safeguard system shall be designed to ensure safe purge, light-off and shutdown procedures, and to monitor
light-off, main flame and boiler operating conditions.
a. The flame safeguard system shall be of the automatically sequenced type with programming
timed and sequenced by a heavy duty, industrial type timer. This timer shall be tamper-proof
and shall be designed so that advancement of the timer to shorten purge will shut down the unit.
b. Provide system with [ultraviolet] [infrared] scanner and electronic relay located in the
front wall which will shut down the fuel within 2 to 4 seconds of loss of flame.
c. Provide scanner output meter in panel for indication of scanner signal strength.
d. The safety system shall include the following limit devices incorporated into a limit circuit:
(1) Flame failure
(2) High boiler outlet pressure
(3) Low fuel oil pressure
(4) Low water level cutout
(5) Low combustion air flow
(6) Low atomizing [air] [steam] pressure
(7) Any additional devices as required by FM or NFPA
[(8) Low fuel oil temperature]
e. Safety system limits specified above shall be displayed on a first out annunciator mounted
in the burner panel. [Provide a common alarm contact to be wired to the operator control console,
specified under VAMS Section 23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT.]
2.5.2.3 Light Off
Failure shall require a manual restart of the programmer. The safety system shall provide a mandatory purge
with the forced draft fan vanes proven open, and a return to proven low fire position before light off. Main
fuel valve shall open for a timed period of 10 seconds during trial for ignition.
2.5.2.4 Circuit Analyzer
Provide a circuit analyzer system, which, by means of 12 or more lights, will indicate which circuits are energized
at specific time, and will thereby indicate any improperly operating circuit.
2.5.2.5 Control Panel
Programmer, limit control, relays, annunciator, shall be mounted in a [NEMA MG 1 control panel, modified with
fully gasketed doors and panels mounted on burner package] [control panel as specified under VAMS Section
23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT].
2.6 FANS
2.6.1 Forced Draft Fan
NOTE: The fan type shall be specified in accordance with FS A-A-59222.
FS A-A-59222, Type [_____], Class 1, except as specified otherwise.
2.6.1.1 Fan Size
Size fans for complete combustion of fuel at maximum firing rate. Maximum fan speed shall not exceed 1800 rpm
at test block rating with [10] [20] [40] percent excess air, taking into account design allowances, corrections
for burner or stoker pressure drop, furnace pressure, combustion air temperature, plant elevation, and other
design factors. Minimum static efficiency at maximum continuous rating shall be [_____] percent. Add the following
allowances for momentary overloads and normal deterioration of fans, firing equipment, and boilers after sizing
fans in accordance with the above to obtain the test block rating:
Coal-Fired Excess Volume Excess Pressure
Forced Draft 20 percent 32 percent
Oil-Fired
Forced Draft 10 percent 20 percent
2.6.1.2 Fan Construction
Fan shall be arrangement [_____] in accordance with AMCA 801. Fan shall have backward inclined or backward curved
single thickness blades. Fan shall have stable characteristics with self-limiting power curve. Construct fan
wheel of steel. Balance fan wheel both statically and dynamically at factory. Provide fan with air cooled roller
bearings mounted in horizontally split pillow blocks. Fan housing shall be welded constructed of a minimum of
12 gage steel. Provide flanged inlet and outlet connections, 50 mm 2 inch plugged opening in low point of scroll
and hinged, quick opening access door in scroll. Provide a multi-blade vortex ball bearing damper in fan inlet
with an extended, ball bearing mounted control lever for field connections to control actuator. Interior of
fan, including wheel, shall be painted with two coats of red primer and one coat of rust resistant enamel with
a total dry film thickness of 0.152 mm 6 mils. Exterior surface of the fan shall have two coats of red primer
with a total dry film thickness of 0.10 mm 4 mils. Cleaning and painting shall be in accordance with the manufacturer's
standards.
2.6.1.3 Fan Drive
Equip fans with [both] [a motor] [and] [steam turbine] drive. The [motor] [and] [turbine] shall be direct connected
to the fan [with a gear type flexible coupling] [with a roller type, hardened steel clutch coupling consisting
of an over-running clutch and double flexing coupling to permit instantaneous change-over from one drive to the
other. One clutch coupling shall be provided between the fan and each driver. Clutch couplings shall be selected
for the maximum torque requirement of the fan, with a 1.5 service factor. Provide a removable guard over each
clutch coupling].
2.6.1.4 Electric Motor
Motor for driving the forced draft fan shall be [_____] volt, three phase, 60 Hz, [open drip-proof] [totally
enclosed fan cooled] [two speed] [variable speed] not less than [_____] kW hp, as specified under "Motors and
Drives" in this section, and shall not overload at the specified capacity with unheated cold air. [Fan motor
shall be suitable for installation in a hazardous location as defined by NFPA 70.] Provide [_____] mm inch thick
steel soleplate for motor. Soleplate shall be common for four motor mounting bolts. Separate parallel soleplate
bars are not acceptable.
2.6.1.5 Steam Turbine
Steam turbine shall drive the fan through a reduction gear shall be single stage, rated at not less than [_____]
kW hp, with inlet steam pressure of [_____] kPa (gage) psig, [_____] degrees C F total temperature and a normal
exhaust back pressure of [_____] kPa (gage) psig or a maximum back pressure of [_____] kPa (gage) psig. Water
rate at full load and normal steam conditions shall not exceed [_____] kg pounds per brake power hour. Maximum
turbine speed shall not exceed [_____] rpm.
a. Turbine Construction: Turbine casing split on the horizontal centerline constructed ofASTM A 48/A 48M
cast iron, with design pressure rating of 1724 kPa (gage) 250 psig at 232 degrees C 450 degrees
F at the inlet, and 379 kPa (gage) 55 psig at 232 degrees C 450 degrees F at the outlet. Turbine
shall also include a stainless steel steam strainer, sentinel relief valve, sight oil level
indicator and two hand valves.
b. Turbine Bearings and Shaft: Bearings horizontally split, ring-oiled, sleeve type water-cooled.
Shaft shall be stainless steel sprayed or chrome plated under the packing glands. Shaft seals
shall be segmented carbon rings with springs and stops.
c. Speed Governor: Variable speed oil relay NEMA Class [A] [D] governor for speed limiting
[and pneumatic operator to maintain an adjustable turbine speed]. [Input to the operator shall
be a 20 to 103 kPa (gage) 3 to 15 psig pneumatic signal.] [Provide an electro-pneumatic transducer
to accept the 4 to 20 mA signal from the controller specified in VAMS Section
23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT.] [Turbine shall go to maximum rated
speed on air failure.]
d. Emergency Overspeed Governor: Completely independent of the speed governor and shall operate
a separate trip valve.
e. Insulation: Turbine shall be insulated and lagged by the manufacturer as specified in Section
23 07 00 THERMAL INSULATION FOR MECHANICAL SYSTEMS.
f. Reduction Gear: High speed, heavy duty, double helical, full pressure lubricated, horizontal
offset type with a service factor not less than 2 provided in a horizontally split casing.
The gear and pinion shall be spray lubricated from a pressure lubricating system. The pressure
lubricating system shall include a shaft driven oil pump, strainer, cooler, pressure gage, low
oil pressure switch, relief valve, reservoir and piping. Provide a high speed, gear type, forge
steel coupling between the turbine and the gear. Reduction gear and turbine shall be mounted
on a common baseplate.
g. Turbine Trip: Provide solenoid valve to trip turbine on failure of induced draft fan.
2.6.1.6 Noise Level
Noise level shall not exceed 85 dBA sound pressure level at 1 1/2 meters 5 feet above the floor and 1 1/2 meters
5 feet from the fan in any direction. [Provide heavy duty sound attenuator with screen on fan inlet to meet
the sound pressure level requirements.]
2.6.2 Induced Draft Fan
NOTE: The fan type shall be specified in accordance with FS A-A-59222.
FS A-A-59222, Type [_____], Class 2.
2.6.2.1 Fan Size
Size fans to handle combustion gases at maximum firing rate. Maximum fan speed shall not exceed 1200 rpm at
test block rating. Design allowances and corrections for furnace, economizer, [scrubber,] [baghouse,] dust collector,
breeching pressure drop when operating at [10] [20] [40] percent excess air, flue gas temperature, plant elevation,
and other design factors shall be made. Add the following allowances for momentary overloads and normal deterioration
of fans, firing equipment and boilers after sizing fans in accordance with the above, to obtain the required
test block rating:
Coal-Fired Excess Volume Excess Pressure
Induced Draft 20 percent 32 percent
Oil Fired
Induced Draft 10 percent 20 percent
2.6.2.2 Fan Construction
Fan shall be arrangement [_____] in accordance with AMCA 801. Fan wheel shall be radial tip design (forward curved-backward
inclined) or straight radial blade with shrouds for high efficiency design. Blading shall be 8 gage minimum
thickness steel [with the addition of 6 mm 1/4 inch thick steel partial blade wear strips, 125 mm 5 inch minimum
width each side of centerplate]. A minimum number of blades is preferred; a maximum of twenty-four is acceptable.
Balance fan wheels both statically and dynamically at factory. Minimum static efficiency at maximum rating including
allowances shall be 67 percent.
NOTE: At the text below, heat slingers may not be necessary on low temperature
flue gas applications.
a. Bearings and Pedestals: Provide fan with water-cooled self-aligning sleeve type bearings
mounted in suitable pillow blocks. Bearings shall be independent high temperature, oil lubricated,
pedestal type with dust seals. [Provide fan shaft heat slingers.] Cast iron or fabricated
steel pedestals mounted on fabricated steel soleplates shall be provided. Provide a self-contained
temperature control valve, with water piping to control temperature of bearings.
b. Housing: Fan shall have 5 mm 3/16 inch thick welded steel housing and inlet boxes which
shall be split with flanged and gasketed joints. Construction shall permit one piece removal
of rotor from rear of fan without disturbing duct connections. Provide hinged, quick opening
access door in scroll and inlet boxes and 50 mm 2 inch plugged openings in low points of scroll
and inlet boxes.
c. Dampers: Provide inlet dampers with multi-parallel-stream flow blades with anti-friction
bearings with 80 mm 3 inch minimum spacers and stuffing boxes to keep bearings cool. Dampers
shall be mounted in 200 mm 8 inch channel frames and interconnected with one extended, ball
bearing mounted control level for connection to control actuator.
d. Welding: Welding of fan components shall be in accordance with current production standards.
High stress fan wheels shall be continuously welded. Low stress exterior housing bracing, dampers,
and other similar components shall be intermittently, plug or continuously welded.
e. Painting: Interior of fan, including wheel, shall be coated with protective coatings suitable
for the flue gas conditions expected to be encountered by this fan. Exterior surface of fan
shall have coatings of quality weather and heat resistant paint. Fan shall be shop assembled
and match-marked by manufacturer before dismantling for shipment. Surface cleaning and painting
shall be in accordance with the manufacturer's standards for the service expected.
2.6.2.3 Fan Drive
Fans shall be equipped with [both] [a motor] [and] [steam turbine] drive. The [motor] [and] [turbine] shall
be directly connected to the fan [with a gear type flexible coupling] [with a roller type, hardened steel clutch
coupling consisting of an over-running clutch and double flexing coupling to permit instantaneous change-over
from one drive to the other. One clutch coupling shall be provided between the fan and each driver. Clutch
couplings shall be selected for the maximum torque requirement of the fan, with a 1.5 service factor. Provide
a removable guard over each clutch coupling].
2.6.2.4 Electric Motor
Motor for driving the induce draft fan shall be [_____] volt, three phase, 60 Hz, [open drip-proof,] [totally
enclosed fan cooled,] variable speed not less than [_____] kW hp, as specified under paragraph entitled "Motors
and Drives" in this section, and shall not overload over the range of the fan with unheated air. [Fan motor
shall be suitable for installation in a hazardous location as defined by NFPA 70.] Provide [_____] mm inch thick
steel soleplate for motor. Soleplate shall be common for each of the four motor mounting bolts. Separate parallel
soleplate bars are not acceptable.
2.6.2.5 Steam Turbine
Steam turbine shall drive the fan through a reduction gear and shall be single stage, rated at not less than
[_____] kW hp, with inlet steam pressure of [_____] kPa (gage) psig, [_____] degrees C Fotal temperature and
a normal exhaust back pressure of [_____] kPa (gage) psig or a maximum back pressure of [_____] kPa (gage) psig
. Water rate at full load and normal steam conditions shall not exceed [_____] kg pounds per brake power hour.
Maximum turbine speed shall not exceed [_____] rpm.
a. Turbine Construction. Turbine casing shall be split on the horizontal centerline constructed
ofASTM A 48/A 48M, cast iron, with design pressure rating of 1724 kPa (gage) 250 psig at 232
degrees C 450 degrees F at the inlet, and 379 kPa (gage) 55 psig at 232 degrees C 450 degrees
F at the outlet. Turbine shall include a stainless steel steam strainer, sentinel relief valve,
sight oil level indicator and two hand valves.
b. Turbine Bearings and Shaft. Turbine bearings shall be horizontally split, ring-oiled, sleeve
type water-cooled. Shaft shall be stainless steel sprayed or chrome plated under the packing
glands. Shaft seals shall be segmented carbon rings with springs and stops.
c. Speed governor variable speed oil relay NEMA Class D governor for speed limiting and pneumatic
operator to maintain an adjustable, preset draft pressure in boiler by variation of turbine
speed. Input to the operator shall be a 30 to 103 kPa (gage) 3 to 15 psig pneumatic signal.
Provide an electro-pneumatic transducer to accept the 4 to 20 mA signal from the controller
specified in VAMS Section 23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT. [Turbine
shall go to maximum rated speed on air failure.]
d. Emergency Overspeed Governor. Completely independent of the speed governor and shall operate
a separate trip valve.
e. Insulation. Turbine shall be insulated and lagged by the manufacturer as specified under
Section 23 07 00 THERMAL INSULATION FOR MECHANICAL SYSTEMS.
f. Reduction Gear. High speed, heavy duty, double helical, full pressure lubricated, horizontal
offset type with a service factor not less than 2 provided in a horizontally split casing.
The gear and pinion shall be spray lubricated from a pressure lubricating system. The pressure
lubricating system shall include a shaft driven oil pump, strainer, cooler, pressure gage, low
oil pressure switch, relief valve, reservoir and piping. Provide a high speed, gear type, forged
steel coupling between the turbine and the gear. Reduction gear and turbine shall [each] be
provided with a [common] [_____] mm inch thick steel baseplate[s].
2.6.2.6 Noise Level
Not to exceed 85 dBA sound pressure level at 1 1/2 meters 5 feet above the floor and 1 1/2 meters 5 feet from
the fan in any direction. Sound attenuation shall be provided to meet the sound pressure level requirements.
2.7 COMPRESSED AIR SYSTEM
2.7.1 Plant Air Compressor
Provide two plant air compressor systems, each with a compressor, filters, intercooler, aftercooler, accessories,
control panel and controls. Provide a receiver for each of the two compressor systems.
2.7.1.1 Air Compressor
NOTE: Select standard L/s SCFM of air to compensate for plant elevation.
Packaged unit, FS XX-C-2816, as modified below. Each compressor capacity shall be not less than [94] [118] [142]
[165] standard L/s [200] [250] [300] [350] scfm of air, at 20 degrees C 68 degrees F and [862] [1379] kPa (gage)
[125] [200] psig at the discharge. Compressor speed shall not exceed [_____] rpm. Compressor shall be [belt
drive] [direct drive] double acting, two stage, with flange mounted water cooled cylinders and heads. Provide
a safety valve between each compressor discharge and its shutoff valve which is required on the discharge piping
of the compressor. Provide a full flow type oil filter for positive forced feed lubrication and an electric
thermostatically controlled immersion heater. Provide lifting lugs and tie downs.
2.7.1.2 Air Filter
Provide a dry type air filter constructed of pleated filter paper with protective stainless steel cloth on each
side. Filter shall also act as a muffler and shall be readily removed for cleaning.
2.7.1.3 Intercooler and Aftercooler
Compressed air intercooler and aftercooler heat exchangers shall each be water cooled, with counter current flow,
and shall be integrally mounted with no external air piping between compressor cylinders and cooler. Design
heat exchangers to cool the total output air flow of the compressor to within 9 degrees C 15 degrees F of the
inlet cooling water temperature. The tube bundles shall be removable for cleaning and inspection.
2.7.1.4 Air Receiver
Vertical tank with a minimum volume of [1585] [1840] [2717] liters [56] [65] [96] cubic feet. Design unit for
[1034] [1724] kPa (gage) [150] [250] psig working pressure in accordance with the ASME BPVC SEC VIII. A receiver
bearing the ASME Code Symbol stamp will be accepted as meeting these requirements. Provide an automatic condensate
trap, safety valve, outlet connection, and a 114 mm 4 1/2 inch pressure gage ([1379] [2068] kPa (gage)[200] [300]
psig range).
2.7.1.5 Electric Motor
Motor shall be [totally enclosed fan cooled], [open-drip proof], [_____] kW hp, [_____] volts, [_____] phase,
60 Hz as specified under paragraph entitled "Motors and Drives" in this section. Control circuits for motor
shall be nominal 120 volts. [Provide removable totally enclosed belt guard.]
2.7.1.6 Controls
Provide controls and shutdowns necessary for automatic operation of the compressor package. House controls in
NEMA 12 control cabinet. Controls shall consist of alarm and running lights, push buttons and selection switches
for automatic dual control, 120 volt control transformer connected to power circuit serving the compressor, along
with necessary time delay and control relays, and indicators. Provide automatic solenoid-operating cooling
a. Start-and-Stop Control: When set for start and stop control, motor shall stop automatically
when discharge pressure reaches maximum pressure setting and start automatically when discharge
pressure falls to minimum setting. Cylinders shall unload during periods of motor shutdown.
b. Constant Speed Control: Compressor shall operate continuously at constant speed. Provide
means to automatically load and unload compressor at preset minimum and maximum pressure settings
respectively. Provide means for automatic release of pressure within cylinders when the unit
is operating without load. Also provide means for manual or automatic unloading of cylinders
during starting of unit. Equip each compressor with a timed control to stop compressor after
a 10 minute unloaded period when air is not used. Compressor shall re-start automatically at
a preset minimum pressure.
c. A lead-lag system shall be provided to alternate compressor start-ups and to operate both
compressors when discharge pressure cannot be met with one operational compressor. The operator
selector switch shall have the following positions:
(1) Both compressors alternating as specified above;
(2) Compressor "A" operation only;
(3) Compressor "B" operation only;
(4) Off.
Total elapsed time shall be recorded for operation time of each compressor.
d. Compressor Safety Controls and Management Panel:
(1) Provide light in panel, alarm and shutdown of compressor for the following functions:
(a) High Main Bearing Temperature
(b) High Discharge-air Temperature
(c) High Discharge-air Pressure
(d) High Water Temperature for [Water Supply,] [Intercooler,]
[Aftercooler,] [Lubrication Oil Cooler]
(e) Excessively High Motor Temperature
(f) Excessive Vibration
(g) Low Crankcase Oil Level
(h) Low Oil Pressure
(2) Provide light in panel and alarm for the following functions:
(a) High Lubrication Oil Temperature
(b) Low Suction Pressure (Dirty Filter)
2.7.2 Instrument Compressed Air System
Provide two instrument air compressor systems each with a compressor, filters, aftercooler, accessories control
panel, controls and receiver, [mounted on one supporting steel base with skids] [mounted separately].
2.7.2.1 Air Compressor
Each compressor shall deliver a minimum of [_____] std. L/s scfm of air at 20 degrees C 68 degrees F at a discharge
pressure of 862 kPa (gage) 125 psig. Compressor speed shall not exceed [_____] rpm. Air compressor shall be
belt drive, single stage, crosshead type, vertical, double acting, water cooled, non-lubricated head type. Compressor
shall be specially designed for non-lubricated service, with a honed cylinder, piston rod packing, piston rings,
and piston wearing rings. Valve guide inserts and wear rings shall be TFE. Valves shall be reversible and hardened,
with stainless steel seat plates for nonlubricated service. Provide necessary sleeves, baffles, and collars
to prevent oil carryover. Provide air-operated, piston type, free air unloaders for capacity reduction and
starting. Mount inlet filter-silencer directly on the air inlet to the cylinder.
2.7.2.2 Aftercooler
Water cooled, with counter current flow, and installed directly between each compressor cylinder and the air
receiver. Design cooler to cool the total output air flow of the compressor to within minus 9 degrees C 15 degrees
F of the inlet cooling water temperature. Tube bundle shall be removable for cleaning and inspection.
2.7.2.3 Air Receiver
Horizontal tank with a minimum volume of [_____] liters cubic feet. Design unit for 1034 kPa (gage) 150 psig
working pressure in accordance with ASME BPVC SEC VIII receiver bearing the ASME Code Symbol stamp will be accepted
as meeting these requirements. Provide an automatic condensate trap, safety valve, and outlet connection.
2.7.2.4 Electric Motor
Motor shall be [totally enclosed, fan controlled], [open drip proof], [_____] kW hp, [_____] volt, [_____] phase,
60 Hz as specified under paragraph entitled "Motors and Drives" in this section. Provide a removable, totally
enclosed belt guard.
2.7.2.5 Accessories
Factory assemble air compressors, drives, controls, air receiver, aftercoolers, and miscellaneous hardware and
mount on a steel supporting base. Provide lifting lugs and tie down attachments. Air, water, and condensate
piping shall be provided and terminated at the edge of the supporting base.
2.7.2.6 Controls
Provide controls and shutdowns necessary for automatic operation of the compressor package. House controls in
NEMA 12 control cabinet. Controls shall include alternator control to switch compressors from lead to lag and
run both compressors when needed; 120 volt control transformer connected to power circuit of compressor; air
discharge pressure gage; selection switches for constant speed for automatic dual control, along with necessary
time delay and control relays. Provide automatic solenoid-operated cooling water valve in the cooling water
line to the compressors and aftercoolers. Factory wire control cabinet and mount as a part of the package.
Compressor safety controls and management panel shall be provided as specified in paragraph entitled "Plant Air
Compressor," located in this section.
2.7.3 Air Dryers
NOTE: Choose the following subparagraph or the subparagraph entitled "Compressed
Air Refrigerated Air Dryer."
2.7.3.1 Compressed Air Desiccant Air Dryer
NOTE: The refrigerated air dryer is limited with an atmospheric dew point of
approximately minus 23 degrees C 10 degrees F equivalent to minus 12 degrees
C plus 10 degrees F at 172 kPa (gage) 25 psig and 2 degrees C 35 degrees F at
690 kPa (gage) 100 psig, and where this may be a problem the desiccant air
dryer should be used as a much lower dew point can be attained.
Provide for systems exposed to freezing temperatures [one] [two] compressed air dual chamber type desiccant dryer[s]
each of sufficient capacity for each system listed below. Each dryer shall be equipped with an automatic regeneration
system which uses [steam heated dry air] [unheated dry air] for the regenerative media. The capacity of each
dryer shall be such that compressed air, in the quantities listed below will be dried from a saturated condition
at [_____] degrees C F to a pressure dew point of minus 40 degrees C F.
Service Capacity (Each Tower)
Baghouses [_____] L/s at 862 kPa (gage)
Ash Handling [_____] L/s at 862 kPa (gage)
Instrumentation [_____] L/s at 862 kPa (gage)
Service Capacity (Each Tower)
Baghouses [_____] cfm at 125 psig
Ash Handling [_____] cfm at 125 psig
Instrumentation [_____] cfm at 125 psig
The contact time of the air in the chambers shall not be less than 4.5 seconds. Velocity of the air shall be
less than that which will fluidize the desiccant bed. Pressure drop through the unit when operating at rated
flow shall not exceed 27 kPa 4 psi. Units shall be field adjustable to maintain the pressure dew point of the
dried air at any preselected value below operating temperature, to minus 40 degrees C F. Units shall have as
an integral part of the construction an indicator showing the water content of the dry air and a calibrated adjustment
control to change the water content to any preselected level. Desiccant dryers shall provide a continuous supply
of dry air by automatically cycling operation of the desiccant beds.
a. Chambers: Designed for 1034 kPa (gage) 150 psig working pressure in accordance with the
ASME BPVC SEC VIII, and so stamped. Each chamber shall be fitted with separate fill and drain
ports so that inlet and outlet piping manifolds need not be removed to fill or drain the chambers.
Each chamber shall be provided with stainless steel screens at the inlet and the outlet to contain
the desiccant bed, pressure gage, and safety valve. Normal air flow during drying shall be
upward through the desiccant chamber. Desiccant shall be spherical activated alumina.
b. Regeneration: Accomplish by depressurizing the chamber on reactivation and purging with
a portion of the dry outlet air from the chamber on stream. Purge air flow shall be downward.
Maximum allowable purge flow rate at design conditions shall be 10 percent of design capacity
of dryer. Purge system shall be controlled by a cam timer such that each desiccant bed is regenerated
as required. Provide a flow control valve, flow indicator, and exhaust muffler for the purge
system.
c. Controls: Cam timer, switches and relays shall be housed in a NEMA 12 control panel, mounted
as part of the dryer. Provide interconnecting wiring in accordance with Division 16. In the
case of electrical power failure, automatic valves shall fail in the open position to allow
the wet gas to pass through the chambers. Provide gages to indicate pressure in each chamber.
d. Accessories: Dryer shall be complete with necessary solenoid operated control valves, check
valves, and interconnecting piping. Mount equipment on a steel base plate suitable for floor
mounting. [Provide pressure reducing valve to reduce pressure to suit desiccant dryer.]
e. Prefilter: Provide prefilter upstream of dryer to remove oil vapor, liquid water, and solid
particles. Prefilter shall have greater than 99 percent efficiency in removing both 0.5 micron
diameter solid particles and 0.5 micro diameter oil aerosol. Filter shall have replaceable
oil absorbing filter element which turns red to indicate saturation with oil and which shall
be mounted in a transparent cast methyl methacrylate tube for visibility and inspection while
on stream. Protect transparent acrylic tube by a safety shield.
f. Afterfilter: Provide an additional afterfilter for instrument air. Filter shall combine
three filter mechanisms - mechanical separation, coalescence and absorption in a single, cartridge
type unit. Filtration efficiency shall be greater than 99.99 percent at 0.5 micron particle
size for oil and other contaminants. A visible color change shall indicate when element should
be replaced.
[2.7.3.2 Compressed Air Refrigerated Air Dryer
NOTE: Choose this subparagraph or the above subparagraph entitled "Compressed
Air Desiccant Air Dryer."
NOTE: The refrigerated air dryer is limited with an atmospheric dew point of
approximately minus 23 degrees C 10 degrees F equivalent to minus 12 degrees
C plus 10 degrees F at 172 kPa (gage) 25 psig and 2 degrees C 35 degrees F at
690 kPa (gage) 100 psig, and where this may be a problem the desiccant air
dryer should be used as a much lower dew point can be attained.
Provide for systems not exposed to freezing temperatures a self-contained refrigerated type compressed air dryer
capable of drying [_____] std. L/s scfm of air to an atmospheric dew point of not less than minus 23 degrees
C 10 degrees F with entering air at 38 degrees C 100 degrees F, saturated. Dryer shall be complete with heat
exchanger, a commercial quality refrigeration system, a moisture separator and condensate trap. Maximum operating
pressure of the dryer shall be [_____] kPa (gage) psig. Install dryer between the receiver and distribution
line.
Provide internal tubing, wiring, and piping complete, such that only connections to air inlet and outlet, to
refrigerant compressor contractor, and to condensate drain are necessary.
a. Heat Exchanger: Heat exchanger shall consist of air and refrigerant coils surrounded by
aluminum granules of sufficient mass to ensure adequate cooling capacity for varying air flow
loads without causing excessive refrigeration cycling. Moisture separator shall be of centrifuge
type and shall be located within the heat exchanger to provide for moisture separation at point
of minimum air temperature. Suitably control heat exchanger temperature and provide an automatic
control system, whose sensing element is located in the aluminium granules, to shut down the
refrigeration system on low or no load conditions. Provide means to ascertain exchanger temperature.
b. Refrigeration Unit: Hermetically sealed type and shall operate intermittently at all but
maximum load conditions. House entire unit in a steel cabinet. Provide cabinet with access
door and panel for easy access to each part for maintenance and inspection.
c. Instrumentation and Control: Include control panel in dryer cabinet containing:
(1) Indicators for the following services: Inlet air pressure gage, discharge air pressure
gage, inlet air temperature gage, refrigeration compressor suction pressure gage, refrigeration
compressor discharge pressure gage, power interruption light, and high temperature light.
(2) Electrical relays located in an enclosed portion of panel, accessible for ease of servicing.
(3) Green "POWER ON" indicating light.
(4) Controls and interlocks to maintain required compressed air dew point and to cycle air-cooled
condenser with refrigeration compressor.
(5) Dryer capable of automatic zero to 100 percent capacity control. Dryer shall use an automatic
control expansion valve with sensing bulb to control capacity; dryer to have automatic shutdown
switch sensor located at point of lowest temperature to prevent freezing.
d. Filters: Provide a disposable cartridge type prefilter and afterfilter at the air dryer.
Filter cartridges shall have a 517 kPa 75 psi differential pressure rating, and the design flow
clean pressure drop shall not exceed 1.40 kPa 0.2 psi. Filter shall be designed to remove
liquid water and oil particles 5 microns and larger. Provide an additional afterfilter for
instrument air. Filter shall combine three filter mechanisms - mechanical separation, coalescence
and absorption - in a single, cartridge type unit. Filtration efficiency shall be greater than
99.99 percent at 0.5 micron particle size for oil and other contaminants. A visible color change
shall indicate when element should be replaced.
e. Pressure Reducing Regulator: Self-operating type designed for not less than a 1724 kPa
(gage) 250 psig operating pressure, a normal operating temperature range of minus 29 degrees
C 20 degrees F to plus 66 degrees C 150 degrees F, and shall deliver constant reduced pressure
compressed air. Regulator shall have an adjustable outlet pressure range of at least 34 to
690 kPa (gage) 5 to 100 psig with not less than 4 ranges. Provide external adjusting screw
for adjustment throughout each spring range. Provide internal pressure tap for outlet pressure
registration.
]2.8 BREECHING, EXPANSION JOINTS, STACKS AND DAMPERS
2.8.1 Breeching
Rectangular cross section, stiffened on sides, top and bottom, and fabricated of not less than 5 mm 3/16 inch
thick black steel plate unless otherwise noted. Stiffeners shall be not less than 65 by 50 by 6 mm 2 1/2 by
2 by 1/4 inch steel angles welded to exterior with 50 mm 2 inch leg outstanding. Separation of stiffeners shall
not exceed one meter 3 feet o.c. [Connect breeching to [each boiler flue gas outlet,] [intermediate heat recovery
equipment,] [air pollution control equipment,] [and to stack as required].]
2.8.1.1 Breeching Access Doors
NOTE: Specify locations for breeching access and cleanout doors. Where practical
show locations on project drawings. Show access and cleanout door details on
project drawings.
Construct access doors with frame and hinged door of cast iron or reinforced steel plate. Frame shall be not
less than 686 by 787 mm 27 by 31 inches with access opening of not less than 508 by 610 mm 20 by 24 inches.
Connection to breeching shall be gasketed and made with minimum 15 mm 1/2 inch diameter hot-dipped galvanized
bolts, lockwashers, and nuts spaced not more than 125 mm 5 inches on center. Sides of the access door shall
have not less than two quick clamp positive closing latches, with the long side opposite the hinges containing
three clamps to give a gastight seal. Side of access door opposite the hinges shall contain a minimum 80 by
125 mm 3 by 5 inch size handle. Provide a gasket consisting of 10 mm 3/8 inch diameter fire proof resilient
rope seal and mastic compound between the hinged access door and the access door frame. Provide breeching access
doors at the following locations [and where indicated]:
[a. _____
b. _____].
2.8.1.2 Breeching Cleanout Doors
NOTE: Specify locations for breeching access and cleanout doors. Where practical
show locations on project drawings. Show access and cleanout door details on
project drawings.
Construct cleanout doors of not less than 5 mm 3/16 inch thick steel plate. Secure cleanout doors to a 32 by
32 by 5 mm 1 1/4 by 1 1/4 by 3/16 inch thick angle frame with 10 mm 3/8 inch hot-dipped galvanized mounting bolts
welded to the angle frame and spaced not over 150 mm 6 inches on center. Weld frame to breeching and provide
a 3 mm 1/8 inch gasket between frame and cleanout door. Cleanout doors shall be not less than 610 by 610 mm
24 by 24 inches except where breeching dimensions are smaller, in which case the cleanout door shall be full
height of the breeching and not less than 610 mm 24 inches in width. Provide breeching cleanout doors at the
following locations [and where indicated]:
[a. _____
b. _____].
2.8.1.3 Breeching Connections and Joints
Weld breeching joints [unless indicated or specified otherwise]. Welding shall conform to AWS D1.1/D1.1M and
AWS D1.3/D1.3M. Bolts for bolted connections shall be hot-dipped galvanized bolts not less than 15 mm 1/2 inch
diameter and spaced not more than 80 mm 3 inches apart, with hot-dipped galvanized lockwashers, and nuts. Provide
bolted joints with a minimum of 3 mm 1/8 inch thick gaskets. Bolt flanged breeching connections to boilers,
equipment items, dampers, expansion joints, and breeching accessories. Flanged breeching connections to equipment
shall be drilled to match flanges on equipment. Flanged joints shall be sealed welded to make connection gas-tight.
2.8.1.4 Breeching Structural Materials
NOTE: Designer shall detail breeching supports and breeching stiffening. Breeching
hangers shall be designed to carry not less than 5 times the breeching weight,
or the breeching weight plus weight of fly ash when breeching is half full plus
136 kg 300 pounds whichever is greater. Hangers for rectangular breeching
shall be of the trapeze type with angle or channel support members and hanger
rods. Breeching shall be stiffened with angle or channel members as required
to withstand internal breeching static pressure. Designer shall verify that
expansion joint flexure for axial travel is suitable. Expansion joints shall
be detailed on the drawings.
Structural and support materials shall be steel and comply with the applicable sections of the AISC 303 or AISC 350
. [Support and stiffen breeching as indicated].
2.8.1.5 Insulation
Provide insulation on breeching as specified in Section 23 07 00 THERMAL INSULATION FOR MECHANICAL SYSTEMS.
2.8.1.6 Breeching Paint
When breeching is shop fabricated, wire brush and clean interior and exterior with a nonflammable solvent and
paint with FS TT-P-28 heat resistant paint, immediately after fabrication. When breeching is to be fabricated
on the job, prime paint steel sheets, one coat each side, prior to delivery to job site.
2.8.2 Expansion Joints
2.8.2.1 Metallic Breeching Expansion Joints
Provide factory fabricated metallic breeching expansion joints [where indicated]. Expansion joints shall be
guided metal bellows type capable of a minimum of [_____] mm inches of axial travel. Form metal bellows from
not less than 1.60 mm 1/16 inch thick type 321 stainless steel plate. Cover plates shall be not less than 3
mm 1/8 inch thick steel plate.
2.8.2.2 Non-metallic Expansion Joints
Provide factory fabricated non-metallic breeching expansion joints 3 mm 1/8 inch minimum thickness [where indicated].
Expansion joints shall be constructed of fluoroelastomer vulcanized to two plies of knitted wire mesh capable
of a minimum of [_____] mm inches of axial compression, [_____] mm inches of axial extension and [_____] mm inches
of lateral offset [unless indicated otherwise]. Joints shall have a continuous operating temperature rating
of 204 degrees C 400 degrees F, with excursion design standards up to 400 degrees C 750 degrees F. Operating
pressure range shall be minus 34 kPa (gage) 5 psig to plus 34 kPa (gage) 5 psig. Expansion joints shall be pre-formed
with integrally molded corners, suitable for mounting against a 150 mm 6 inch flange. Provide carbon steel backup
bars with slotted holes, bolts, and nuts.
2.8.3 Stacks
2.8.3.1 Stacks With Flue Gas Scrubbers
NOTE: Use stack with acid resistant lining if temperatures below dew point
of flue gas are expected in stack. Designer has to consider down drafts in
stack at low firing rate.
Stacks shall be free standing, self-supporting, steel construction with an acid resistant lining system. Provide
each stack complete with all accessories and appurtenances, including test ports, sampling platforms, ladders,
safety climb devices, anchors, sleeves, insulation, stainless steel base and chair rings, and clean-out door.
a. Construction: Acid resistant lined steel stacks shall be fabricated of [ASTM A 242/A 242M
, Type 1] [ASTM A 36/A 36M] structural steel plate with a 1.60 mm 1/16 inch corrosion allowance.
Design shall include a static analysis of stack of wind loadings and critical wind velocity
and dynamic analysis of stack including damping of vortex shedding and seismic response. Minimum
steel plate thickness of stack shall not be less than 6 mm 1/4 inch. Stack sections shall be
of welded construction and fabricated in sections not to exceed normal shipping limitations.
Longitudinal seams shall have full penetration, continuous butt-welded joints. The section
or horizontal joints of the stack shall also be full penetration continuous buttwelds. Welding
shall be done by certified welders. Secure the stack to the foundation by a base plate with
gussets, counterforts or steel beams provided as required. A reinforced concrete foundation,
the design of which shall be approved by the stack manufacturer, shall be provided. Base construction
of the stack shall transmit forces and moments in the shell to the [foundation] [supporting
steel] without local stresses of appreciable magnitude being induced in the shell or exceeding
the allowable stresses of the supporting [concrete] [steel].
b. Stack-Breeching Connection: A lined breeching connection of the same wall thickness as
the stack shall be welded to the stack and the steel jacket of the stack reinforced as required
to compensate for the structural strength of steel removed. A flange for bolting breeching
to the connection shall be provided. A hinged cast iron or steel cleanout door with refractory
lining and heavy duty steel frame shall be provided at the bottom of the stack. Frame and door
shall be fitted gastight. Door shall be a minimum of 457 by 610 mm 18 by 24 inches in size.
c. Block Lining: Provide a lining consisting of inorganic borosilicate glass blocks bonded
to the steel. Entire inside of each stack shall be sandblasted to a white metal blast finish.
Block shall be 40 mm 1 1/2 inches thick, constructed of totally organic-free closed cell borosilicate
glass. Blocks shall be shaped to reasonably match the inside of the stack and beveled to match
adjacent blocks such that no gaps between surfaces shall be greater than 3 mm 1/8 inch. Blocks
shall be bonded to the steel and adjacent blocks with a two compound, urethane adhesive membrane.
Adhesive membrane shall be trowelled to both the steel and block. Blocks shall be pressed into
place in accordance with the manufacturer's instructions to provide a bond free of voids.
d. Optional Stack Lining: In lieu of the borosilicate glass block lining specified above an
acid resistant cast insulating refractory lining with an acid resistant membrane liner over
an anchoring system may be provided. Lining system shall be suitable for use in the pH range
of 1.6 to 8. Liners composed of calcium aluminate or calcium silicate will not satisfy service
requirements of the stack system.
(1) Membrane Liner: Urethane-Asphalt, or suitable similar material, which has been used successfully
in similar installations to protect stacks from acid attack when flue gas temperatures are below
their dew point. Service temperature range of the liner shall be minus 40 to plus 82 degrees
C 180 degrees F, when applied to a thickness of 3 mm 1/8 inch.
(2) Refractory Lining: Potassium silicate single component chemically hardened cement or two
component potassium silicate bonded cement with an inert filler material such as silica, or
suitable similar material, gunite applied or cast monolithic insulating refractory, suitable
for use on flue gas from 66 degrees C 150 degrees F and up to 232 degrees C 450 degrees F and
resistant to continuous exposure of sulfuric acid, nitric and nitrous acid, carbonic acid and
other liquids, in the pH range of 1.6 to 8 and formed when the surface of the stack is at a
temperature at and below the flue gas dewpoint.
(3) Membrane/Refractory Lining Certification: Manufacturers of the membrane liner and the
refractory lining shall certify that the lining system to be provided in the stack shall be
suitable for the specific application, considering the flue gas temperature, velocities, moisture
content and corrosive qualities of the fuel being burned.
(4) Refractory Lining Anchor System: Tinned metal anchors welded to the stack wall, or wire
mesh fabric welded to anchors welded to stack wall, shall support the refractory lining of the
stack. Tinned anchor system shall have anchors welded to stack shell on vertical spacing not
greater than 200 mm 8 inches on center and horizontal spacing not greater than 100 mm 4 inches
on center, in staggered rows to provide a minimum of 48 4.5 anchors per square meter foot.
Wire mesh fabric shall be No. 10 or 12 wire gage made into a welded fabric approximately 50
by 50 mm 2 by 2 inches mesh size. Mesh shall be welded to anchors o.c. not to exceed [250]
[300] mm [10] [12] inches. Mesh and anchors shall be of the same alloys.
(5) After anchor system is welded in place, blast clean entire inside surface of stack including
stack base, and anchor system to a white metal blast finish and then coat with two coats of
membrane liner to a total minimum thickness of 3 mm 1/8 inch. The stack base shall be included
in the coating system. Prior to the installation of the refractory, spark test coated surfaces
with a holiday detector to ensure membrane is free of voids. Refractory lining shall be trowelled
on or pneumatically applied to a minimum thickness of 76 mm 3 inches.
(6) Design of anchor system and application of refractory lining shall permit expansion and
prevent cracking of the refractory.
e. Manufacturer's Calculations Required for Foundation and Stack:
(1) Foundation (including bearing and moment forces) reinforcement and anchor bolts
(2) Stack
- Stresses due to various loading conditions including wind and seismic loads
- Vibration and damping
- Heat transfer at various design and ambient conditions
- Expansion profiles
- Shipping and erection stress analysis
f. Finish: Stacks shall be shop coated prior to shipping from the factory. After erection,
touch-up damaged shop coated surfaces and apply a prime coat and two coats of finish paint suitable
for the temperatures and environmental exposure as specified in Section 09 90 00 PAINTS AND
COATINGS.
g. Platforms and Ladders: Stacks shall be provided with platforms for sampling tests, monitoring
equipment maintenance and obstruction-lighting maintenance. Access to lower platform shall
be by ASTM A 242/A 242M, Type 1, steel [stairway] [catwalk or platform] [ladder] from the [heating
plant] [pollution control building] [ground level]. Design for a minimum live load on platforms
to be 488 kg 100 pounds per square meter foot. Platforms shall be not less than 1220 mm 48
inches wide and the sampling platform shall be a minimum width of 610 mm 2 feet plus the stack
diameter, but not more than 3 meters 10 feet in width. Toe plates shall be not less than 150
mm 6 inches high around the platform perimeter. Platform railings shall have two intermediate
railings. Ladders shall be [caged] corrosion resistant steel, 406 mm 16 inches wide with 305
mm 12 inch rung spacing. Ladders shall be provided from the lower platform to the top of each
stack and shall be provided with a full length stainless steel safety climb device. The climb
device shall consist of a notched rail attached to the rings' centerline with a sleeve which
rides on the rail and locks into position on a sudden downward pull. Two belts for attaching
the device to the climber shall be furnished.
h. Anchor Bolts: Provide anchor bolts, nuts, washers and sleeves to properly anchor the stacks.
Stack manufacturer shall furnish certified dimensional drawings showing location for setting
bolts in concrete.
i. Miscellaneous:
(1) Sample Ports: Provide two sample ports at 90 degree orientation to each other about 1220
mm 4 feet above platform. Each sample port shall consist of a 100 mm 4 inch diameter pipe welded
to the steel jacket and provided with a flange and mating blind flange. Provide openings required
for installation of opacity monitor and SO2 analyzer specified in VAMS Section
23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT. [Locations of sample ports and instrumentation
openings shall be as detailed on drawings].
(2) Obstruction Lighting: Provide an obstruction lighting system for each heating plant stack,
consisting of one red, flashing, 300 millimeter hazard beacon atop each stack, two steady burning,
red obstruction marker lights halfway up each stack, photoelectric and flasher controls, weather-tight
terminal boxes, cable, and conduit.
(a) Hazard Beacons: Federal Aviation Administration FAA AC 150/5345-43, Type L-866.
(b) Obstruction Lights: FAA AC 150/5345-43 Type L-810.
(3) Painter's Trolley: Provide a ring of Type 304 stainless steel to support an inspection
or painter's trolley. Provide a three wheel standard steel flat rail trolley of 227 kg 500
pounds capacity. Guide trolley to prevent it from leaving the track.
NOTE: Velocity cones decrease cold air down drafts and increase velocity of
discharged flue gas but increase flow resistance of stack; they may be used
when justified.
(4) Velocity Cone: Provide stack with an acid resistant lined truncated velocity cone. Velocity
cone shall be lined with the same insulating refractory as applied to the stack with a 80 mm
3 inch minimum thickness. Cone shall be 1220 mm 4 feet long, bolted to top of stack, and shall
taper to a diameter of [_____] mm inches inside.
2.8.4 Dampers
2.8.4.1 Multilouver Dampers
Provide factory fabricated parallel multilouver dampers for two position service (open-closed) and opposed blade
damper for modulating control. Construct damper frame of distortion resistant welded steel channels with raised
seat to ensure free nonbinding operation of blades and to keep blades square in the frame. Construct blades
of [_____] mm inch thick steel plate in a stressed skin airfoil-shape with fully welded seams containing no external
ribs. Blade deflection in mm inches shall not exceed the length in mm inches divided by 360, consistent with
AISC 360 beam deflection criteria. Blade shafts shall be stainless steel. Blades shall be pinned to blade shafts.
Louver shaft bearings shall be outboard type and shall be self-lubricating and self-cleaning. Bearing seals
shall be gastight.
a. Multilouver Damper Linkage: Damper linkage shall be adjustable and of pinned construction
for easy removal and shall be designed to handle full operation torque. Linkage on dampers
in clean flue gas areas shall operate from a single connection point.
b. Control Damper Operators: Provide control damper operators as shown. Operators shall be
pneumatically operated with positive positioning, manual override, and hydraulic or oil immersed
gear trains. Each operator shall be full-proportioning type, with spring return to position
shown in case of loss of power. Damper operating speeds shall be selected and adjusted so that
operators will remain in step with controllers. Operators acting in sequence with other operators
shall have adjustment of control sequence as required by the operating characteristics of the
system.
c. Two-Position Damper Operations: Two-position damper operators shall be pneumatically operated
with air cylinder, four-way valve, and solenoid valve arrangement.
2.8.4.2 Guillotine Dampers
NOTE: Guillotine dampers shall be used for open-shut service where tight shutoff
is required for example, for air pollution control equipment bypass dampers.
Provide factory fabricated guillotine dampers with heavy structural frame rigid enough to support the extended
blade and external loads through the breeching flange. Damper shall be capable of operating without precleaning
or manual assistance under normal operating conditions. Provide enclosed bonnets [where indicated]. Provide
80 mm 3 inch diameter cleanout ports on both sides for cleaning bottom sections.
a. Guillotine Damper Blade: A stress-relieved flat plate. Damper blade shall be nonwarping;
intermediate blade supports are acceptable to limit blade deflection. Leading edge of damper
blade shall be beveled and capable of guiding damper blade into frame seat. Blade guides shall
be continuous and self-cleaning and capable of preventing binding from deposits and damage from
misalignment. Bonnet guides shall be removable and damper shall be designed so that a damper
blade can be replaced without opening the frame.
b. Guillotine Damper Bonnet Seal: Provide bonnet seal to effectively seal against atmospheric
leakage under normal operating conditions.
c. Double-bladed Guillotine Dampers: Provide where indicated. Damper frame, blades, and bonnet
seals shall be as specified for single-bladed guillotine dampers, except frame shall be thicker
and two blades shall be provided instead of one. Double-bladed guillotine damper shall provide
absolute zero leakage across damper blades. This shall be accomplished by utilizing a blower
to introduce air into the space between the damper blades. Blower shall be mounted on damper
frame complete with isolation valve. Blower shall have sufficient capacity to maintain a pressure
of at least 498 Pa 2 inch water column over breeching pressure.
d. Guillotine Damper Drive: A positive dual endless chain drive capable of driving damper
in both directions. Chain-drive head shaft shall have sufficient torsional rigidity to prevent
binding of blade when the blade is stalled. Damper shall be motor-operated with manual override.
Design drive mechanism to prevent back driving of motor. Entire drive mechanism shall be of
a simple design and require no routine maintenance other than inspection. Chain shall be capable
of operating up to the stall torque of the damper drive motor.
e. Electric Motor: Motor shall be [totally enclosed fan cooled] [open drip-proof], [_____]
kW hp, [_____] volt, [_____] phase, 60 Hz, as specified under paragraph entitled "Motors and
Drives" in this section. Provide removable, totally enclosed chain guard.
2.9 COAL HANDLING EQUIPMENT
2.9.1 Railroad Hopper Car Thawing System
NOTE: Pit type railcar thawing system is capable of operating on natural gas,
liquified petroleum gas or No. 2 fuel oil. The radiant heat (infrared) type
railcar thawing system can only burn natural gas or liquified petroleum gas
or use electric resistance heaters. The radiant heat (infrared) type provides
a slower method of thawing but causes less damage to the railroad car finish
and is preferred provided natural gas or liquified petroleum gas or electrical
power is economically available and permitted by current D.O.D. policy.
Hopper car thawing system shall be pit-type or prefabricated surface mounted enclosed type [or electric radiant
type] hopper car thawing unit and shall include burners, controls, combustion air blowers, fuel storage and handling,
and related work. Design system to thaw 56 Mg 55 ton, 71 Mg 70 ton and 102 Mg 100 ton capacity coal cars.
System shall be capable of thawing [_____] bottom hopper unloading coal cars simultaneously. Railroad hopper
car thawing system shall utilize [No. 2 fuel oil] [natural gas] [liquified petroleum gas] as a fuel. Provide
a sufficient number of heaters to have a minimum heat input of 2198 kW 7,500,000 Btu/hr per car station, with
heaters distributed under hopper car, or under and beside hopper car, such that the entire car is heated. Locate
burner pits or heater units for even heating of the hopper cars without subjecting air hoses, air brake equipment,
and bearings to excessive heat.
2.9.1.1 Pit-type Railroad Hopper Car Thawing System
a. Pit-type Thawing Unit: Pit-type hopper car thawing unit shall be complete with a refractory
lined steel box, burner assemblies, steel burner enclosure with cover, valves, piping, and hinged
main pit protective covers. Each pit shall have the capacity to generate 366 kW 1,250,000 Btu/hr
when burning [No. 2 fuel oil] [natural gas] [liquified petroleum gas]. Burners shall fire
horizontally and tangentially into the pit from opposite sides to heat the refractory lined
pit up to radiant temperature. Heat shall be transferred to the hopper car by radiation from
hot refractory surfaces and by convection from exhaust gases and evaporated moisture to rail
car bottom and sides. Construct pit outer shell of not less than 6 mm 1/4 inch thick corrosion
resistant steel plate, with the end plates of 10 gage (3.42 mm0.1345 inch) steel. Provide supporting
flanges and handling loops on both ends and provide cap strips on top of both sides. Place
cast iron heat deflecting plates with overlapping edges on pit sides and bottom supported off
the ledge on the outer shell. Provide a minimum 25 mm one inch air space between plates and
outer shell. Pit side walls and bottom shall have a minimum 65 mm 2 1/2 inch thickness of standard
firebrick with one course of standard end skew brick along the top of the side walls. Firebrick
shall be easily replaceable. End section shall have not less than 114 mm 4 1/2 inch thick precast
high temperature refractory panels. Provide burner refractory ignition tiles with steel jacket
casings having mounting lugs for bolting to end plates of pit. Provide concrete railroad ties
adjacent to each thawing pit. Deliver combustion air to burners by means of pressure blowers
which take fresh air from outside thawing area. Factory wire and assemble heaters, control
panels, blowers, and zone controls. Shop fabricate burner piping and control valve assemblies.
NOTE: Designer shall make selection here based on fuel to be used in thawing
system.
b. Fuel System: [Provide complete fuel system for operation with, [natural] [liquified petroleum]
gas including piping, regulators, low and high pressure limit switches interlocked with combustion
controls, gages, solenoid valves, shutoff valves, and other accessories which may be required
for each manufacturer's particular system.] [Provide complete fuel system for operation with
duplex fuel oil pump set with [_____] liters gallon horizontal [below] [above] ground fuel tank
and other accessories which may be required for each manufacturer's particular system. Provide
fuel oil system in accordance with the requirements specified under paragraph entitled "Fuel
Oil System" this section.]
c. Burner controls shall meet Industrial Risk Insurers' (I.R.I., formerly F.I.A.) requirements.
Connect fuel system piping to fuel supply piping as indicated. Burners shall be controlled
(modulate) to regulate heat output to suit the operating requirements. Provide a manual light-off,
low pressure [gas] [oil] pilot for automatic light-off of each thawing unit.
d. Air System: Provide complete air systems for operation with blowers, inlet silencers, gages,
shutoff valves, low pressure limit switches interlocked with combustion controls, and other
accessories which may be required for each manufacturer's particular system.
e. Control Panel: Provide centrally located control panel, with panel front consisting of
a graphic display of the thawing system. Display shall be approximately to scale and coordinated
with control and light indication for combustion air blowers and on-off control of convenient
groups of heaters. Provide on-off control with indicating light for each thawing pit. Panel
shall have a [NEMA 12] [NEMA 3R-8], dust-tight enclosure with internal equipment and wiring
accessible from the panel front. Provide nameplates on panel front to designate function of
switches and indicating lights. Controls shall be suitable for [_____] volt, [_____] phase,
60 Hz operation. Provide and mark terminals for connections with the exception of the neutral.
Terminal blocks shall be 600 volt rated. Control relays shall have convertible contacts and
shall have rating suitable for intended services but in any case, not less than 10 amp, 600
volt rating. Components shall be oiltight type. Connections to panel shall be watertight.
Motor starters for combustion air blowers shall be installed in each respective blower cabinet.
2.9.1.2 Surface Mounted Enclosed Railroad Hopper Car Thawing System
a. Surface Mounted Enclosed Thawing Unit: Burner shall be of multiport cast iron construction
and provide for even heating of radiant elements. Heater design shall be essentially the same
for undercar and sidecar heaters, with heat transmitted to hopper car by both radiation and
convection. Design burner and radiant element for radiation being the primary mode of heat
transfer. Make radiant element over the burner of a heavy corrosion-resistant metal material.
Design burner to operate on [No. 2 fuel oil] [natural gas] [liquified petroleum gas], and such
that open flame from combustion will not extend beyond the emitter surface either during normal
operation or in the event of emitter deterioration or burnout. Provide shields where necessary
to direct radiation and hot exhaust gases to hopper car surface. Provide means for shielding
car air hoses, air brake equipment, and bearings from excessive heat. Provide each heater with
individual heater control boxes constructed as to provide positive air pressure inside control
box. Control boxes shall contain mixing valve for maintaining proper gas-air ratio for satisfactory
combustion. Locate gas and air piping connections for easy removal of individual burners.
Deliver combustion air to heaters by means of pressure blowers which take fresh air from outside
thawing area to ensure continued satisfactory combustion of gaseous fuels. Factory wire and
assemble thawing units, control panels, blowers, and zone controls. Fuel system and burner
control for oil fired units shall be as specified under paragraph entitled "Pit-Type Railroad
Hopper Car Thawing System" above.
b. Burner Controls (for gas fired units): Burners shall be electrically ignited with controls
meeting I.R.I. requirements. Provide a gas pressure regulator for serving not more than eight
individual burners. Regulator shall reduce gas pressure in supply line to pressure required
for burners. Provide each burner with an air regulating valve for fuel-air ratio adjustment.
Regulating valve shall contain positive vibration-proof locking device for maintaining critical
adjustment.
c. Control Panel: Provide centrally located control panel with panel front having a graphic
display of the thawing system. Display shall be approximately to scale and coordinated with
control and light indication for combustion air blowers and on-off control of individual heaters.
Provide a modulating control for each heater to regulate heat output to suit the operating requirements.
Panel shall be [NEMA 12] [NEMA 3R-8], dust-tight enclosure with internal equipment and wiring
accessible from the panel front. Provide nameplates on panel front to designate function of
switches and indicating lights. Controls shall be suitable for [_____] volt, [_____] phase,
60 Hz operation. Provide and mark terminals for connections, with the exception of the neutral.
Terminal blocks shall be 600 volt rated. Control relays shall have convertible contacts and
shall have rating suitable for intended service but not less than 10 amp, 600 volt rating.
Components shall be an industrial design of the oiltight type. Connections to the panel shall
be watertight. Motor starters for combustion air blowers shall be installed in each respective
blower cabinet.
[d. Thawing unit may be an electric radiant heat thawing unit which includes self-contained
heater banks such as under-car outside the rail heater sections, lower side car heater sections
and vertical side car heater sections, with reflectors, hinged cover, waterproof and weatherproof
wired terminal blocks and zone controls for flexibility of operation.]
2.9.1.3 Shed
NOTE: Shed should be used in the severe climate areas. Consult appropriate
DM-2 series design manuals for design criteria for the shed.
Provide shed of pre-engineered metal space frame construction with corrugated siding as indicated. Provide ventilation
with roof vents and openings along bottom of sides of shed.
2.9.2 Top-Mounted Railroad Hopper Car Shaker
NOTE: When noise is a major factor of concern, design a shaker enclosure with
acoustical treatment which will be capable of reducing the noise to a tolerable
level.
Provide top-mounted rail car shaker complete with shaker, frame, vibrator, motors, hoists, hoist frame, [enclosure],
and controls. Design unit for operation under all weather conditions.
2.9.2.1 Shaker
Shaker shall operate with a nominal 4 mm 5/32 inch stroke at 1200 rpm. Stroke shall be generated by large eccentric
SAE 1045 steel shaft mounted in high capacity, self-aligning, spherical roller bearings. Seal bearings with
a double piston ring labyrinth seal and dust and water slinger to retain lubricant and prevent entry of contaminants.
Shaker frame shall be stress-relieved, welded steel construction. Fabricate frame of heavy steel plate, with
bearing housing seats machined after stress relieving. Provide four lifting eyebolts of heat-treated forged
alloy steel for connecting to hoist chains.
a. Shaker Electric Motor and Drive: Motor shall be totally enclosed, fan cooled, 1,800 rpm,
[_____] volt, three phase, 60 Hz, not less than 15 kW 20 hp, as specified under paragraph entitled
"Motors and Drives" in this section. Motor shall be mounted on heavy spring isolated supporting
frame with adjustable motor base. Shaker shall be belt driven with special deep groove sheaves,
taper locking type hubs, and constant belt tensioning spring.
2.9.2.2 Shaker Hoist
Hoist shall be twin hook type having a rated capacity exceeding the weight of the shaker unit. Hoist shall have
a lift of not less than 7 1/2 meters 25 feet with a hoist speed of not less than 0.08 meter per second (m/s)
16 feet per minute (fpm). Hoist shall have not less than 460 mm 18 inch long sling chains for connecting hoist
to shaker lifting eyes, and hooks shall have U-bolt safety latches. Hoist shall be mounted on an electrified
trolley as specified in Section 41 22 13.13 BRIDGE CRANES.
Shaker Hoist Electric Motor: Motor shall be totally enclosed, [fan cooled], [non ventilated], 1,800 rpm, [_____]
volt, three phase, 60 Hz, not less than 5 1/2 kW 7 1/2 hp as specified under paragraph entitled "Motors and Drives"
in this section. Motors shall be high slip type and shall with thermal overload protection embedded in the windings.
2.9.2.3 Controls
Provide [remote] [pendant] pushbutton station for both shaker and hoist operation. Provide automatic controls
with upper and lower screw type limit switches to limit hook travel, slack cable limit switch to stop lowering
of hooks when car shaker has been lowered on top of car, electrical interlock to prevent operation of car shaker
motor until shaker is lowered on car, and electrical interlock to prevent operation of hoist motor while car
shaker is running. Mount electrical equipment in NEMA 4 enclosures.
2.9.2.4 Frame [and Enclosure]
Provide frame [and enclosure] as indicated for support of hoist and shaker unit [and for attenuation of noise].
2.9.3 Car Pullers
2.9.3.1 Capstan Car Puller
NOTE: Choose this subparagraph or the subparagraph entitled "Reversible Drum
Type Car Puller."
Designed with capacity of not less than 4540 kg 10,000 pounds of starting pull and an average rope speed of approximately
0.23 m/s 45 fpm. Assembly shall be totally enclosed, weatherproof, and suitable for exterior installation with
vertical capstan. Capstan shall be semisteel alloy construction designed for use with marlin-covered wire rope.
a. Accessories: Provide capstan complete with accessories, including controls, rope, rope
storage reel, car hooks, sheaves, snatch blocks, anchors, and ratchet holdback.
b. Rope: Capstan rope shall be not less than 25 mm one inch outside diameter marlin clad wire
rope with a breaking strength of not less than 13,620 kg 30,000 pounds.
c. Rope Storage Reel: Construct rope storage reel of metal, hand operated with the drum not
less than 300 mm 12 inches in diameter and the reel faces not less than one meter 3 feet in
diameter. Drum shall have not less than [_____] mm inches face width and store not less than
[_____] meters feet of 25 mm 1 inch diameter marlin clad wire rope.
d. Electric Motor: [Totally enclosed], [fan cooled], high starting torque, reversing type,
[_____] volt, three phase, 60 Hz, not less than 7 1/2 kW 10 hp as specified under paragraph
entitled "Motors and Drives" in this section.
2.9.3.2 Reversible Drum Type Car Puller
NOTE: Choose this subparagraph or the above subparagraph entitled "Capstan
Car Puller."
NOTE: Designer shall detail required footings and foundations based on the
selected puller and soil conditions at each plant site.
[Single drum reversing] [Double drum] type designed with a capacity of not less than [_____] kg pounds of running
rope pull. Starting pull capacity shall be not less than twice the running pull capacity. Provide assembly
on one-piece heavy steel base with weatherproof motor and gear reducers suitable for exterior location.
a. Puller: Unit shall consist of a [_____] mm inch pitch diameter by [_____] mm inch face,
spirally grooved for [_____] mm inch diameter wire rope with sealed anti-friction bearings,
alloy steel ring mounted spur gear and SAE 1045 steel shaft. Provide an SAE 1045 steel countershaft
with anti-friction pillow blocks and heat-treated alloy steel spur pinion roller chain drive
with steel sprockets and enclosed guard. Speed shall be a minimum of [_____] m/s fpm.
(1) Electric Motor: [Totally enclosed], [fan cooled], high starting torque, reversing type,
[_____] volt, [_____] phase, 60 Hz, not less than [_____] kW hp, as specified under paragraph
entitled "Motors and Drives" in this section. Provide clutch for engaging and disengaging
power to drum.
(2) Reduction Gear: AGMA 2009 or AGMA 2011, "AGMA Gear Handbook," sized for the motor horsepower
with motor base and coupling. Motor shall include motor mounted disc brake in dust and watertight
enclosure. Provide rope overwind switch assembly and rotary type limit assembly.
b. Accessories:
(1) Rope Sheaves: Provide four stationary type, 762 mm 30 inch pitch diameter single sheaves
and one 762 mm 30 inch take up sheave assembly. Sheave shall be cast steel, grooved for [_____]
mm inch diameter rope and shall be oriented horizontally and mounted in a welded steel frame
with self-lubricating bronze bushings. Provide removable steel rope guards over sheaves.
(2) Wire Rope: Wire rope shall be not less than [_____] mm inch in diameter with a breaking
strength of not less than [_____] kg pounds. Rope shall consist of six 19 wire strands of improved
plow steel rope with hemp center.
(3) Safety Warning System: Provide a safety warning system, including an audible horn and
three flashing lights to indicate cars in motion. System shall activate 30 seconds before puller
motor is energized and shall not deactivate until puller motor is de-energized. Provide a permanent
warning sign at each light indicating "RAILCAR IN MOTION."
(4) Miscellaneous: Provide reversing controls, car hooks, snatch blocks, and anchors.
2.9.4 Track Hopper
NOTE: Determine when a track hopper will be required.
Welded construction of not less than 6 mm 1/4 inch thick [410 stainless steel] [structurally reinforced steel
plate lined with 8 gage (4.18 mm0.1644 inch) 410 stainless steel] plate not less than 4 1/4 meters 14 feet wide
and 8 1/2 meters 28 feet long. Side slopes not less than 60 degrees from horizontal. Interior bolts shall have
flat heads. Support hopper from concrete pit walls as indicated.
2.9.4.1 Track Girders
Two wide flanged beams designed for Cooper's E-[_____] loading with 50 percent impact allowance and sized at
W [_____] x [_____]. Provide beams with cross struts for rigidity and bearing plates for mounting on pit wall
as indicated.
2.9.4.2 Grating
Hopper grating between rails of [_____] by 10 mm 3/8 inch steel bars and [_____] by 10 mm 3/8 inch steel cross
bars with openings [100] [150] by [100] [150] mm [4] [6] by [4] [6] inches. Grating outside rails shall have
openings 100 by 100 mm 4 by 4 inches and be constructed of same size steel bars as specified above. Construct
grating in removable panels and support from concrete pit walls and by steel angle supports resting on track
girders.
2.9.4.3 Cover
Structurally reinforced 5 mm 3/16 inch thick raised pattern floor plate. Cover for portions of hopper outside
rails shall be hinged with edges turned down. Construct cover between rails in easily removable sections with
handles.
2.9.4.4 Hopper Outlet
Flanged not less than [_____] by [_____] mm inches. Outlet shall contain a water-collecting reclaim hopper type
coal gate not less than [_____] by [_____] mm inches in size along with a dust tight metal slip joint, constructed
of not less than 6 mm 1/4 inch thick [4l0 stainless steel] [structurally reinforced steel plate lined with 8
gage (4.18 mm0.1644 inch) 410 stainless steel] plate. Slip joint shall be of split construction to allow for
disassembly and replacement. Design slip joint to allow for necessary flexibility to take care of deflection
of hopper outlet due to varying coal loads and temperature variations without imposing load on feeder enclosure.
Provide rope packing or other resilient gasket material to make the slip joint completely dust tight.
2.9.5 Truck Hopper
NOTE: Determine when a truck hopper will be required.
Welded construction of not less than 6 mm 1/4 inch thick [4l0 stainless steel] [structurally reinforced steel
plate lined with 8 gage (4.18 mm0.1644 inch) 410 stainless steel] plate not less than 3 meters 10 feet wide and
3 meters 10 feet long. Side slopes not less than 60 degrees from horizontal. Interior bolts shall have flat
heads. Support hopper from concrete pit walls as indicated.
2.9.5.1 Grating
Hopper grating shall have openings 90 by 90 mm 3 1/2 by 3 1/2 inches. Construct grating of 125 by 13 mm 5 by
1/2 inch steel bars and 25 by 10 mm one by 3/8 inch steel cross bars. Weld grating and make in sections for
ease of removal. Provide two intermediate support beams sized not less than W8 x 31 arranged for a maximum grating
span of 1016 mm 3 feet 4 inches.
2.9.5.2 Hopper Outlet
Flanged not less than [_____] by [_____] mm inches. Outlet shall contain a water-collecting reclaim hopper type
coal gate not less than [_____] by [_____] mm inches size.
2.9.5.3 Cover
Structurally reinforced 5 mm 3/16 inch thick raised pattern floor plate. Construct cover in sections with handles
for ease of removal.
2.9.6 Reclaim Hoppers
Welded construction of not less than 6 mm 1/4 inch thick structurally reinforced steel plate lined with 8 gage
(4.18 mm0.1644 inch) 410 stainless steel plate not less than 3 meters 10 feet wide and 3 meters 10 feet long.
Side slopes not less than 60 degrees from horizontal. Interior bolts shall have flat heads. Support hopper
from concrete pit walls as indicated.
2.9.6.1 Grating
Hopper grating shall have openings 90 by 90 mm 3 1/2 by 3 1/2 inches. Construct grating of 125 by 13 mm 5 by
1/2 inch steel bars and 25 by 10 mm one by 3/8 inch steel cross bars. Weld grating and make in sections for
ease of removal. Provide two intermediate support beams sized not less than W8 x 31 arranged for a maximum grating
span of 1016 mm 3 feet 4 inches.
2.9.6.2 Hopper Outlet
Flanged not less than [_____] by [_____] mm inches. Outlet shall contain a special reclaim hopper gate not less
than [_____] by [_____] mm inches.
2.9.6.3 Reclaim Hopper Cover
Structurally reinforced 5 mm 3/16 inch thick raised pattern floor plate. Construct cover in sections with handles
for ease of removal.
2.9.7 Belt Feeder
Totally enclosed, dust tight, approximately [_____] meter feet between pulley centers, designed to operate at
a speed not to exceed [_____] m/s fpm, and having a capacity of not less than [_____] Mg tons per hour of [_____]
size coal. Provide belt feeder complete with continuous belt, shafts, pulleys, idlers, belt cleaner, frame,
enclosure, reduction gear, and drive motor.
2.9.7.1 Head and Foot Shafts
Cold rolled steel, not less than [_____] mm inches and [_____] mm inches in diameter respectively. Mount shafts
in antifriction roller bearings with forced lubricating type fittings. Mount head shaft in fixed pillow blocks.
Foot shaft shall have screw-type takeups with not less than a [_____] mm inch adjustment. Shafts shall fit tight
in pulley hubs.
2.9.7.2 Pulleys
Welded steel type with detachable compression grip-type hubs, steel plate ends, and crown faces 50 mm 2 inches
wider than the belt width. [Provide an adjustable spring loaded or counter weighted type rubber bladed belt
wiper beneath the head pulleys].
2.9.7.3 Belt
Mine Safety and Health Administration (MSHA) approved fire resistant construction, belt not less than [_____]
mm inches wide, [_____] ply, [_____] kg ounces per square meter foot, with 3 mm 1/8 inch thick oil and chemical
resistant cover on carrying side 0.79 mm 1/32 inch thick oil and chemical resistant rubber cover on under side.
Cover shall be fire resistant. Belt shall have a cover tensile strength of not less than [_____] kPa psi and
friction between plies of not less than [_____] kPa psi. Belt shall have vulcanized splice.
2.9.7.4 Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, [_____] phase, 60 Hz, not less than [_____] kW hp as
specified under paragraph entitled "Motors and Drives." Motor shall be direct connected by means of flexible
coupling with guard to a reduction gear.
2.9.7.5 Reduction Gear
Alloy steel helical gear type enclosed in oiltight housing. Provide an adjustable base for motor and reducer
unit. Drive from output shaft of the speed reducer to the conveyor head shaft shall be by means of finished
steel roller chain conforming to ASME B29.100 running over cut tooth sprockets conforming to ASME B29.100 and
complete with steel plate chain guard. Roller chain attachments shall conform to ASME B29.100. Provide means
to properly tension drive chain.
2.9.7.6 Backstop
Differential band brake type, cam type, or internal type to prevent reversal of belt.
2.9.7.7 Idlers
Flat type with 125 mm 5 inch diameter steel shells, malleable iron end brackets, grease sealed roller-type antifriction
bearings, and self-cleaning angle bases. Idler spacing shall be not greater than 1372 mm 4 feet 6 inches. Return
idler shall be of the flat single-pulley type having 125 mm 5 inch diameter steel shells, grease sealed roller-type
antifriction bearings spaced on not more than [_____] meter feet centers. Provide self-aligning training type
idlers, as required, to ensure proper training of the belt. Provide additional idlers, as required, beneath
track or truck hopper for support of belt and coal and to properly protect belt from impact caused by the coal.
Extend grease pipes to one side for four point lubrication from tunnel walkway.
2.9.7.8 Load Skirts
Steel plate 6.35 mm 1/4 inch thick supported by structural brackets from conveyor frame. Skirts shall have rubber
strips along the bottom edge to seal belt. Strips shall be easily adjustable by means of a clamp bar arrangement
not requiring slotted bolt holes.
2.9.7.9 Frame, Supports, and Enclosure
Construct frame of either structural steel channel side stringers properly tied and braced for support of head
and foot shafts with 12 gage (2.66 mm0.1046 inch) steel deck plate the full length of the feeder, or integrally
formed plate conveyor and deck frame. Support idlers from conveyor frame. Support frame from floor of tunnel
[by steel channel legs] [as indicated]. Completely enclose feeder in a dust-tight enclosure constructed of not
less than 10 gage (3.42 mm0.1345 inch) steel plate with easily removable gasketed side panels containing handles
at each panel end.
2.9.7.10 Loading Hopper
Constructed of not less than 10 mm 3/8 inch thick steel plate connected to bottom flange of the track or truck
hopper. Provide an adjustable regulating gate adjacent to loading hopper for regulating height of coal on the
belt.
2.9.7.11 Vibrating Feeder
Flat pan type vibrating feeder to convey coal from the day hopper to the belt conveyor. Pan shall be [_____]
mm inches wide by [_____] mm inches long, with 150 mm 6 inch sides, constructed of 6.35 mm 1/4 inch thick stainless
steel. Provide feeder with integral electromechanical drive and a remote controller. Controller shall contain
operating switches and rate of flow adjustment and the power source for the feeder drive. Controller shall be
designed for 460 volt, 60 Hz supply voltage. Support feeder from the hopper.
2.9.8 Shallow-In-Built Bar Flight Feeder and Receiving Hopper
Bar flight feeder shall be totally enclosed, dusttight type with shallow-in-built [track] [truck] hopper. Bar
flight feeder shall have a horizontal length of [_____] meter feet [_____] mm inches between sprocket centers,
operate at not greater than [_____] m/s fpm, and have a capacity of not less than [_____] Mg tons per hour of
[_____] size coal. Provide feeder complete with continuous chains and attached bars, terminal sprockets, gears,
shafts, bearings, troughs, enclosure, frames, [truck] [track] hopper, grating, regulating gate, hinged inspection
doors, discharge chute, electric motor, reduction gear, and supports.
2.9.8.1 Head and Foot Shafts
Head and foot shafts shall be not less than [_____] mm inches and [_____] mm inches in diameter, respectively.
Construct shafts of coal rolled steel and mount in antifriction roller bearings. Mount head shaft in fixed pillow
blocks and foot shaft shall have screw-type takeups with not less than [_____] mm inches adjustment.
2.9.8.2 Terminal Sprockets
Cast iron terminal sprockets with chilled rims not less than 380 mm 15 inches in diameter. Foot shaft sprockets
shall be split type in two 180 degree sections to facilitate removal in shallow pit.
2.9.8.3 Chains and Flights
Chains shall be bar link type each having a pitch of not greater than 150 mm 6 inches and an ultimate strength
of not less than 20,430 kg 45,000 pounds. Construct chain of heat treated carbon steel components with not less
than a 22 by 38 mm 7/8 by 1 1/2 inch wide center link, 10 mm 3/8 inch wide by 38 mm 1 1/2 inch thick side bars,
fastened with 18 mm 5/8 inch diameter pins. Construct bar flights of 10 mm 3/8 inch thick steel bars not less
than 50 mm 2 inches high with flight width of not less than [_____] mm inches. Flight spacing shall be such
that feeder shall move the required coal with a head shaft speed not greater than [_____] rpm.
2.9.8.4 Frame and Enclosure
Construct feeder frame of structural steel properly tied and braced, complete with guides and track for both
the carrying and return runs, of not less than 80 by 80 by 10 mm 3 by 3 by 3/8 inch steel angles with not less
than 6 mm 1/4 inch high renewable carbon steel wear bars. Enclosure shall be dusttight of not less than 10 gage
(3.42 mm0.1345 inch) commercial hot rolled steel plate. Enclosure shall be removable in sections. Top and side
panels at head and foot sections shall be hinged and removable for access to chain sprockets.
2.9.8.5 Trough
Construct trough with flat bottom of not less than 10 mm 3/8 inch thick steel plate. Trough shall be removable
and constructed with flanged discharge opening.
2.9.8.6 Hopper
Construct hopper not less than 2 1/2 meters 8 feet long and 3 meters 10 feet wide of structurally reinforced
10 mm 3/8 inch thick steel plate lined with 10 gage (3.42 mm0.1345 inch) 410 stainless steel plate. Hopper sides
shall not slope less than 55 degrees from the horizontal. Construct hopper with a shield over the return run
so that coal is fed directly to the bottom conveying run.
2.9.8.7 Grating
Hopper grating shall have openings 90 by 90 mm 3 1/2 by 3 1/2 inches. Construct grating of 65 by 10 mm 2 1/2
by 3/8 inch steel bars and 20 mm 3/4 inch diameter steel rods. Weld grating and make in sections for ease of
removal. Provide intermediate beams to support the grating.
2.9.8.8 Flight Feeder Drive
Flight feeder shall be driven by an electric motor direct connected by means of flexible coupling to a reduction
gear unit having alloy steel helical or herringbone gears and antifriction bearings enclosed in oiltight housing.
Provide an adjustable base for motor and gear. Drive from output speed shaft of the reduction gear to the conveyor
head shaft shall be by means of standard finished steel roller chain conforming to ASME B29.100 running over
cut tooth sprockets conforming to ASME B29.100 and complete with steel plate chain guard. Roller chain attachments
shall conform to ASME B29.100.
2.9.8.9 Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, three phase, 60 Hz not less than [_____] kW hp as specified
under paragraph entitled "Motors and Drives" in this section.
2.9.9 Bucket Elevator
Dusttight [centrifugal discharge] [continuous bucket] type having approximately [_____] meter feet [_____] mm
inches sprocket centers, vertical chain and bucket, operating at a speed not to exceed [_____] m/s fpm, and
having a capacity of not less than [_____] Mg tons per hour of [_____] size coal. Provide bucket elevator complete
with continuous double chains and attached buckets, upper and lower sprockets, gears, shafts, bearings, casing,
top hood, discharge spout, bottom boot, access doors, electric motor drive, reduction gear, service platform,
and accessories.
2.9.9.1 Head and Foot Shafts
Cold rolled steel not less than [_____] mm inches and [_____] mm inches in diameter, respectively. Mount shafts
in antifriction roller bearings with forced lubricating type fittings. Mount head shaft in fixed pillow blocks.
Foot shaft shall have screw-type takeups with not less than a [_____] mm inch adjustment. Shafts shall fit tight
in sprocket hubs.
2.9.9.2 Terminal Sprockets
Cast iron with chilled rims. Head sprockets shall be not less than [_____] mm inches in diameter and foot sprockets
not less than [_____] mm inches in diameter.
2.9.9.3 Buckets and Chain
Construct buckets of [malleable iron] [not less than [_____] mm inch steel plate] not less than [_____] mm inches
long, [_____] mm inches wide, and [_____] mm inches deep. Buckets shall be mounted by not less than four bolt
attachments to double strand of steel bushed chain each having an ultimate strength of not less than [_____]
kg pounds and pitch of [_____] mm inches. Bucket spacing shall not be greater than [_____] mm inches.
2.9.9.4 Backstop
Differential band brake type, cam type or internal type to prevent reversal of chain and buckets in case of power
failure.
2.9.9.5 Elevator Casing
Not less than [_____] by [_____] mm inches inside of not less than [_____][gage] [mminch thick] commercial hot
rolled mild steel plate with 50 by 50 by 6 mm 2 by 2 by 1/4 inch corner angles for full height of elevator casing.
Construct casing in standard sections from 3 to 3.66 meters 10 to 12 feet high with 50 by 50 by 6 mm 2 by 2 by
1/4 inch angle flanges at the end of each section. Provide a hinged inspection door not less than 610 by 760
mm 24 by 30 inches in the section immediately above the boot section [and where indicated]. Casing and inspection
doors shall be of dust-tight construction with flange angles continuously welded and gasketed. No makeshift
repairs or field patching to overcome leakage shall be permitted. Casing interior shall be given a 1.60 mm 1/16
inch thick coating of coal tar primer and enamel in accordance with SSPC PS 11.01.
2.9.9.6 Head Section
Not less than [_____] mm inch thick commercial hot rolled mild steel plate in heavy angle frame with split, hinged,
and removable top cover hood. Construct hood of not less than [_____] mm inch thick commercial hot rolled mild
steel plate with flanged discharge throat built of not less than [_____] mm inch thick commercial hot rolled
mild steel plate. Design head section to support the drive machinery and head bearings. Provide maintenance
access ladder and platform conforming to applicable OSHA regulations [as indicated].
2.9.9.7 Boot Section
Not less than [_____] mm inch thick commercial hot rolled mild steel plate in heavy angle frame with curved and
renewable bottom plate built of not less than [_____] mm inch thick commercial hot rolled mild steel plate, and
flanged inlet. Take up and foot terminal bearing on one side of the boot shall be mounted in a bolted removable
side panel so the foot shaft and [sprocket] [sprockets] may be removed through the side of the door. Bolt end
panels so they are removable for cleanout and inspection.
2.9.9.8 Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, three phase, 60 Hz not less than [_____] kW hp, as specified
under paragraph entitled "Motors and Drives" in this section. Motor shall be direct connected by means of flexible
coupling to a reduction gear.
2.9.9.9 Reduction Gear
Alloy steel herringbone or helical gear type enclosed in oiltight housing. Provide an adjustable base for motor
and reduction gear unit. Drive from output shaft of reduction gear to elevator head shaft shall be by means
of standard finished steel roller chain conforming to ASME B29.100 running over cut tooth sprockets conforming
to ASME B29.100 and complete with steel plate chain guard. Roller chain attachments shall conform to ASME B29.100
. Provide means to properly tension drive chain.
2.9.9.10 Anchoring Brackets
Provide steel brackets at intervals [as indicated] at [not less than [_____] meters feet over centers] for anchoring
elevator and to increase rigidity.
2.9.10 Rotary Vane Feeder
Provide a fully enclosed, dusttight, rotary vane feeder designed to feed [_____] size coal at a constant rate
of not less than [_____] Mg tons per hour. Provide feeder complete with housing, feeder vanes, removable panels
and inspection doors.
2.9.10.1 Body
Construct feeder body dusttight of not less than 12.7 mm 1/2 inch thick formed carbon steel plate with 19.05
mm 3/4 inch thick flanges. Continuously weld joints both inside and out. Top cover of feeder between inlet
and outlet flanges shall be removable to allow access to interior of feeder. Provide hinged inspection doors
in both sides of the outlet section.
2.9.10.2 Feeder Vanes
Feeder section shall consist of not less than four vanes, equally spaced, extending radially from drive shaft.
Feeder section shall be not less than 457 mm 18 inches long and 457 mm 18 inches in diameter. Construct shaft
of turned and polished cold rolled steel mounted in externally flanged babbitted type bearing blocks with forced
lubrication type fittings. Protect bearings with felt seal between bearing blocks and feeder body.
2.9.10.3 Drive Sprocket
Provide cast iron drive sprocket with chilled rims. Coordinate diameter with drive motor and reduction gear
for required feeder speed.
2.9.10.4 Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, three phase, 60 Hz, not less than [_____] kW hp as specified
under paragraph entitled "Motors and Drives" in this section. Motor shall be directly connected by means of
flexible coupling to a reduction gear unit having alloy steel helical or herringbone gears and antifriction bearings
enclosed in oiltight housing. Provide an adjustable base for motor and reduction gear unit. Drive from output
speed shaft of the reduction gear to the conveyor head shaft shall be by means of finished steel roller chain
conforming to ASME B29.100 running over cut tooth sprockets conforming to ASME B29.100 complete with steel plate
chain guard. Roller chain attachments shall conform to ASME B29.100.
2.9.11 Screw Conveyors
Provide each dusttight and furnished complete, with trough, screw, inlet and discharge spouts, discharge gates,
bearings, bearing hangers, dust cover, electric motor, reduction gear, [service platform,] and supports.
2.9.11.1 Inlet and Discharge Spouts
Arrange as indicated. Spouts shall be flanged and square with opening dimensions equal to inside diameter of
trough.
2.9.11.2 Screw Trough
Provide dusttight screw trough with trough covers. Support trough by 6 mm 1/4 inch thick steel plate feet at
not less than 3 meters 10 foot intervals. Individual trough sections shall not be greater than 3 meters 10 feet
long with steel angle end flanged connections.
2.9.11.3 Bearings and Hangers
Provide thrust bearings and trough end dust seals for both drive and tail bearings. Thrust bearings shall be
bronze in antifriction pillow blocks. Screw hanger bearings shall be rabitted-type, with cast iron hangers
having removable bearing caps held in place by a U-bolt. Design hangers to fit inside the conveyor trough and
equip bearing for grease lubrication with grease fittings penetrating the dust cover to allow bearings to be
greased without removing dust cover. Hangers shall not be located at trough joints, feed, or discharge openings.
Locate hangers at not less than [3.66 meter12 foot intervals for screw diameters larger than 250 mm 10 inches
] [and] [3 meters10 foot intervals for screw diameters 250 mm 10 inches in diameter and smaller].
2.9.11.4 Conveyor Screws and Couplings
Construct conveyor screws of helocoid-type flights and connect with cold rolled steel couplings. Assemble conveyor
screws so that at the hangers there is 180 degrees rotation between the flight ends of each adjacent screw section.
Screw flight shall end over last discharge spout so bare pipe extends across this area to prevent material carry-over.
2.9.11.5 Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, three phase, 60 Hz, not less than [_____] kW hp as specified
under paragraph entitled "Motors and Drives" in this section. Install motor at discharge end of conveyor. Motor
shall be supported by a unit bracket attached to the screw conveyor trough end plate and shall be connected to
reduction gear through a -belt drive. Reduction gear shall be shaft mounted, double reduction type mounted directly
on conveyor shaft. Provide tie rods, when required, to prevent reduction gear rotation and for adjusting belt
tension.
2.9.11.6 Service Platforms
Provide service platform conforming to OSHA regulations as indicated to properly maintain and service conveyor
drive unit.
2.9.12 Belt Conveyor
Inclined and approximately [_____] meter feet between pulley centers, operated at a speed not to exceed [_____]
m/s fpm, and have a capacity of not less than [_____] Mg tons per hour of [_____] size coal. Provide belt conveyor
complete with continuous belt, shafts, pulleys, idlers, takeups, belt cleaner, frame with conveyor cover and
walkway, transfer chute, hopper, emergency stop cord and switch, alignment switch, reduction gear, electric motor,
bin high level limit switch and alarm.
2.9.12.1 Head and Foot Shafts
Construct shafts of turned and polished cold rolled steel not less than [_____] mm inches and [_____] mm inches
in diameter, respectively. Mount shafts in antifriction roller bearings with forced lubricating type fittings.
Mount head shaft in fixed pillow blocks. Foot shaft shall have screw-type takeups with not less than [_____]
mm inches adjustment.
2.9.12.2 Takeups
[Three pulley guided vertical counter weighted type] [Screw type] to maintain proper belt tension. Shafts shall
be as specified above and not less than [_____] mm inches in diameter. Provide a safety device to prevent free
fall of take-up pulley. Takeups shall provide a minimum adjustment of 1.5 percent of total belt length.
2.9.12.3 Pulleys
Welded steel type with detachable compression grip-type hubs, steel plate ends, and crown faces 50 mm 2 inches
wider than the belt width. Provide a multiple belt scraper at each head pulley.
2.9.12.4 Magnetic Pulley
Drive pulley of [_____] conveyor shall be a nonelectric permanent magnet type designed to remove tramp iron.
Provide a removable pan to collect the tramp iron.
2.9.12.5 Belt
Synthetic fabric, not less than [_____] mm inches wide, a minimum of [_____] ply, with 3 mm 1/8 inch thick oil
and chemical resistant cover on carrying side, [1.59] [0.79] mm [1/l6] [1/32] inch thick oil and chemical resistant
rubber cover on under side. Cover shall be fire resistant. Belt shall have a tension pull strength of not less
than [_____] N per mm pounds per inch of belt width. Belt shall have vulcanized splice.
2.9.12.6 Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, three phase, 60 Hz, not less than [_____] kW hp as specified
under paragraph entitled "Motors and Drives" in this section. Motor shall be direct connected by means of flexible
coupling with guard to a reduction gear.
2.9.12.7 Reduction Gear
Alloy steel helical gear type enclosed in an oil tight housing. Provide an adjustable base for mounting motor
and reducing unit. Drive from the output shaft of the speed reducer to the conveyor head shaft shall be by means
of finished steel roller chain conforming to ASME B29.100 running over cut tooth sprockets conforming to ASME B29.100
and complete with steel plate chain guard. Roller chain attachments shall conform to ASME B29.100. Provide
means to properly tension drive chain.
2.9.12.8 Backstop
Differential band brake type, cam type, or internal type to prevent reversal of belt.
2.9.12.9 Emergency Stop Cord and Switch
Provide emergency stop cord the length of the conveyor to actuate a switch for stopping the conveyor. Switch
shall have flag to indicate actuated switch and shall have positive safety lock that cannot be accidentally reset.
Cord shall be not less than 2.38 mm 3/32 inch galvanized aircraft cable with a minimum 1.19 mm 3/64 inch vinyl
or nylon protective coating. Provide sufficient number of switches to prevent cable weight from actuating switch.
2.9.12.10 Belt Alignment Switch
Provide on each side of belt mounted off conveyor frame or discharge chute to stop conveyor under belt misalignment
or runoff conditions. Mount switches on breakaway mounts to prevent damage from runaway belt.
2.9.12.11 Idlers
Troughing idlers shall be the [20] [35] degree three-pulley type with 125 mm 5 inch diameter steel shells, malleable
iron end brackets, grease sealed roller type antifriction bearings, and self-cleaning angle bases. Troughing
idler spacing shall be not greater than 1.37 meters 4 feet 6 inches, with additional idlers at the loading point.
Return idler shall be of the flat single-pulley type having 125 mm 5 inch diameter steel shells, grease sealed
roller type antifriction bearings and spaced on not more than 3 meters 10 foot centers. Provide self-aligning
training type trough and return idlers at not greater than 15.24 meters 50 foot intervals to ensure proper training
of belt. Extend grease pipes to one side for four point lubrication from walkway.
2.9.12.12 Load Skirts
Not less than 6 mm 1/4 inch thick steel plate and supported by structural brackets from conveyor frame. Skirts
shall have rubber strips along bottom edge to seal belt. Strips shall be easily adjustable by means of a clamp
bar arrangement not requiring slotted bolt holes.
2.9.12.13 Frame, Supports, and Walkway
NOTE: Designer shall detail footings based on load and soil conditions at each
plant site. Walkway shall be detailed.
Frame shall be of the structural steel truss type with head and foot terminals framed of structural steel. Support
frame from grade on structural A-frames set on concrete footings as indicated. Support idlers on not less than
150 mm 6 inch channel stringers braced and tied to structural steel truss frame. Provide a 12 gage (2.66 mm
0.1046 inch) steel deck plate for full length of conveyor. Provide a curved belt cover constructed of not less
than 16 gage (1.52 mm0.0598 inch) corrugated galvanized metal having removable panels on the walkway side for
access to the idlers. Provide walkway not less than 914 mm 36 inches wide, supported from the structural steel
framing for the entire length of the conveyor. Walkway shall be complete with handrails and metal nonslip grating
meeting the requirements of 29 CFR 1910-SUBPART D.
2.9.12.14 Discharge Hopper
Construct discharge hopper of not less than 6 mm 1/4 inch thick steel plate to discharge on a discharge chute.
Provide a discharge hood built of 10 gage (3.42 mm0.1345 inch) steel plate enclosing the top, front, and sides
above the discharge hopper.
2.9.13 Coal Scales
Stationary, automatic, dust-proof, belt-fed, batch type with rated capacity of not less than [_____] Mg tons
per hour and a hopper capacity of 91 kg 200 pounds. Coal scales shall be complete units, including the body,
belt feeder, feeder drive, bypass, weighing mechanism, weigh hopper, controls, counters, and other items required
to make a completely automatic coal scale.
2.9.13.1 Body
Dusttight, of welded heavy steel plate construction with base angles not less than 6 mm 1/4 inch thick. Top
plate, bypass plate, and reducer mounting plate shall be not less than 6 mm 1/4 inch thick, with other plates
of not less than 11 gage (3.04 mm0.1196 inch) steel plate. Provide large, gasketed, dusttight doors with adjustable
pre-set compression type latches and forged steel hinges for inspection and maintenance purposes. Door openings
shall be sufficient to allow removal of feeder and hopper without removal of screws or bolts.
2.9.13.2 Feeder
Feeder shall be a self-contained unit with an endless belt which shall be capable of being removed from one end
or side. Construct feeder of heavy rigid steel frame with an 11 gage (3.04 mm0.1196 inch) stainless steel plate
to support the belt on the carrying run. Head and take-up shafts shall be cold rolled steel carried on self-aligning
ball bearings equipped with dust seals and fitted for pressure lubrications. Bearings shall be capable of being
lubricated during scale operation. Take-up shaft shall have screw-type take-up bearings and pulleys shall be
crown faced steel for proper belt tracking.
2.9.13.3 Feed Belt
Channel type and of endless construction without splice. Belt shall be not less than 7.94 mm 5/16 inch thick
of three ply heavy fabric core construction with chemical and abrasion resistant rubber coating. Feeder skirts
and leveling plate shall be stainless steel and shall be arranged to provide a continuous stream of constant
width and depth coal on the feed belt.
2.9.13.4 Electric Motor And Drive
Totally enclosed [_____] volt, [_____] phase, 60 Hz, with heavy duty reduction gear not less than 0.56 kW 3/4
hp as specified under paragraph entitled "Motors and Drives" in this section. Scale shall be capable of bypassing
coal without disconnection of the drive. Drive disconnection shall not be required for feeder removal unless
special provisions are made for a quick and simple drive disconnection.
2.9.13.5 Coal Bypass
Provide a quick-operating coal bypass with an easily operable lever located on the outside of scale body. Operating
lever operation shall instantly bypass coal around the feeder section and weighing mechanism without release
of belt tension to prevent entry of coal between belt and pulley or support plates. Bypass construction shall
not restrict inlet opening size for normal scale operation.
2.9.13.6 Weighing Mechanism
Enclose in a dusttight compartment. Construct weighing mechanism of cold rolled steel for minimum deflection,
warp, and twist. Pivot points shall be self-aligning with hardened double bearing surfaces. Weighing mechanism
shall be complete with weight lever, tare adjustment, and compensator, [with design subject to approval by the
Contracting Officer], and scale shall be guaranteed to weigh coal accurately within 0.25 percent.
2.9.13.7 Scale Weigh Hopper
Construct scale weigh hopper and discharge gate of not less than 14 gage stainless steel plate, continuously
welded and stiffened with angle irons. Weigh hopper shall be of such design and construction to ensure clean
discharge.
2.9.13.8 Controls
Provide controls, except those required for weigh hopper discharge, prewired and located in a [NEMA 12] [NEMA
3] dusttight enclosure. Provide circuit breaker interlocked with the electrical panel door. Control circuits
shall be two wire nominal 120 volt systems obtained by using an isolation transformer with one side grounded
and shall be wired to a single terminal block which shall be included in the electrical panel. Segregate circuits
of different voltage levels. Controls shall include large, oiltight, industrial type pushbuttons for use as
"start-stop," "test," and "dump" switches mounted on the scale body adjacent to the electrical panel.
2.9.13.9 Counters
Mount a mechanical type coal counter on the scale body. Counter shall be rugged, reliable, with heavy duty register
and designed so that double counting is impossible. [A remote motor operated counter shall be furnished located
on the coal handling control panel in the control room. Counter shall be designed so that double counting is
impossible.] [Provide a contact closure for sending a pulse signal of each weigh hopper discharge to the operator
control console, specified under VAMS Section 23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT.]
2.9.13.10 Scale Inlet
Scale inlet shall contain coal gate with opening not less than 457 by 457 mm or 406 by 508 mm 18 by 18 inches
or 16 by 20 inches along with a dusttight metal slip joint constructed of not less than 4.76 mm 3/16 inch thick
steel plate. Slip joint shall be of split construction to allow for installation after coal scale is in place.
Design slip joint to allow the necessary flexibility to take care of deflection of the [bunker] [silo] outlet
due to varying load and temperature variations without imposing load on the scale. Rope packing or other resilient
gasket material shall be provided to make the slip joint completely dusttight.
2.9.13.11 Scale Outlet Hopper
Not less than 6 mm 1/4 inch thick 410 stainless steel plate of capacity not less than 227 kg 500 pounds and 13
mm 1/2 inch thick steel plate flanges.
2.9.14 Stoker Hopper Extension
Stoker hopper extensions shall be dusttight and bolted to hopper furnished with stokers. Construct hopper extensions
approximately as indicated of 6 mm 1/4 inch thick 410 stainless steel plate with structural stiffeners. Hopper
extension shall hold not less than [_____] Mg tons of coal at a density of 800 kg per cubic meter 50 pounds per
cubic foot. Hopper extensions shall have bolted emergency firing doors of not less than 610 by 610 mm 24 by
24 inches which shall contain a 152 by 152 mm 6 by 6 inch glass observation window. Connections shall be dusttight.
2.9.15 Coal Valve
Dusttight and drip proof of the double ladder rack-and-pinion type sized as indicated for each valve. Valve
shall be capable of closing through a standing coal column. Valve opening shall be full size with no bridges,
internal braces, or other barriers.
2.9.15.1 Valve Body
Not less than 6 mm 1/4 inch thick formed 410 stainless steel with heavy 19 mm 3/4 inch thick flanges. Continuously
weld joints in contact with coal both inside and out and grind smooth. Valve body shall have dusttight steel
gate assembly cover with molded gasket for removal of gate without removing the coal valve. Provide a minimum
of two dusttight poke holes with rigid covers and molded gaskets.
2.9.15.2 Valve Gate
Drip proof and siftproof of 10 mm 3/8 inch thick steel plate with an 11 gage (3.04 mm0.1196 inch) 410 stainless
steel liner. Support gate by ball bearing rollers with 16 gage (1.52 mm 0.0598 inch) stainless steel shells
equipped with felt grease seals and stainless steel grease retainers. Provide rollers with grease fittings extended
through the valve body for pressure lubrication. Design gate so that supporting rollers, racks, and pinions
are located completely out of the coal stream. Racks shall be cold formed and self cleaning, with stainless
steel self cleaning pinions located over racks for positive tooth engagement.
2.9.15.3 Operating Shaft
Mount operating shaft in ball bearings with felt seals, stainless steel shells, stainless steel grease retainers,
and grease fittings. Provide handwheels with proper finger clearance or pocket sheaves with heavy hot-dipped
galvanized chain and chain guard as indicated. Handwheels and sheaves shall be not less than 457 mm 18 inches
in diameter. Provide valves with mechanical type position indicator consisting of large pointer and legend
to indicate the position of the valve gate.
2.9.15.4 Electric Motor Operators
Provide motor operators where indicated and capable of remote operation from the coal handling control panel.
Operator shall consist of totally enclosed, fan cooled, high torque, [_____] volt, [_____] phase, 60 Hz motor
as specified under paragraph entitled "Motors and Drives" in this section with reduction gear, clutch and limit
switches. Motor horsepower shall be as recommended by the manufacturer. Provide motorized valves that have
manual operators, with fail-safe interlocks that make manual operation impossible while motor is operating.
2.9.16 Track and Reclaim Hopper Valves
Dusttight, double rack and pinion type, with water collecting trough. Valve shall have inlet opening not less
than [_____] by [_____] mm inches in the direction of gate travel with a larger outlet opening. Inlet and outlet
shall be flanged and constructed of mild steel.
2.9.16.1 Valve Body
Not less than 10 mm 3/8 inch thick mild steel continuously welded both internally and externally and lined with
11 gage (3.04 mm0.1196 inch) 410 stainless steel plate where body comes in direct contact with coal. Construct
inlet skirt of not less than 6 mm 1/4 inch thick 410 stainless steel with outlet body plates constructed of 10
mm 3/8 inch thick mild steel lined with 11 gage (3.04 mm0.1196 inch) 410 stainless steel plate. Construct water
collecting trough of not less than 11 gage (3.04 mm0.1196 inch) 410 stainless steel plate and containing water
sprays for flushing. Valve body shall have dust-tight steel gate assembly cover with molded gasket for removal
of gate without removing the coal valve. Provide a hinged access panel not less than [_____] by [_____] mm inches
in the direction of gate travel with compression-type latches over the water collecting trough for removing
obstructions.
2.9.16.2 Valve Gate
Slope gate plate toward water collecting trough and mount it on large ball bearing rollers with 16 gage (1.52
mm0.0598 inch) stainless steel shells equipped with felt grease seals and stainless steel grease retainers.
Provide rollers with grease fittings extended through the valve body for pressure lubrication. Gate shall be
U-shaped with ladder racks on both sides and shall be constructed of not less than 16 mm 5/8 inch thick mild
steel lined with 11 gage (3.04 mm0.1196 inch) 410 stainless steel plate. Gate design shall be such that supporting
rollers, racks, and pinions are located completely out of the coal stream. Racks shall be cold formed and self-cleaning,
with stainless steel, self cleaning pinions over racks.
2.9.16.3 Operating Shaft
Mount in ball bearings with felt seals, stainless steel shells, stainless steel grease retainers, and grease
fittings. Mount a reduction gear on the gate shaft and provide an ample gate clearance pocket in the body to
ensure ease of operation through a standing column of coal. Handwheel for operating the valve shall be not less
than 457 mm 18 inches in diameter.
2.9.17 Chutes
Construct coal chutes dusttight as indicated of not less than 6 mm 1/4 inch thick 410 stainless steel plate.
Weld chutes with flanges located as indicated to facilitate equipment and chute section removal. Flanges shall
be not less than 10 mm 3/8 inch thick steel and gasketed to maintain dust-tight seal. Poke holes and access
panels shall be provided where indicated.
2.9.18 Coal Presence Indicators and Equipment Response Switches
May be of the following types and shall be interlocked with the coal handling controls to indicate equipment
failures, coal stoppages, and provide for a semi-automatic system. Enclosures for components shall meet the
requirements of NEMA Type 7, Class I, Division I, Groups C and D, and NEMA Type 9, Class II, Division I, Groups
E, F, and G.
2.9.18.1 Type A - Diaphragm Type Presence Indicator
Pressure-sensitive to presence of coal consisting of housing, diaphragm, limit switches, wiring, and mounting
bracket flanges. Housing shall be either cast iron, stainless steel, or protected cast aluminum, with synthetic
diaphragm as recommended for coarse slightly abrasive materials. Diaphragm deflection shall actuate a limit
switch to indicate coal presence. Design unit so that maintenance, diaphragm replacement and sensitivity adjustment
can be made from outside the bin. Type and number of contacts and voltages shall be as indicated on the control
diagrams.
2.9.18.2 Type B - Paddle Type Presence Indicator
Paddle mounted on a counterweighted horizontal shaft so that deflection of the paddle rotates a cam which actuates
a limit switch in a control box mounted on the shaft. Unit shall consist of paddle, shaft, enclosure, limit
switches, wiring, and mounting brackets. Shaft shall be cold rolled steel and paddle shall be stainless steel
with control enclosure of cast iron, stainless steel, or suitably protected cast aluminum. Type and number of
contacts and voltages shall be as indicated on the control diagram. Mount shaft in ball bearings equipped with
suitable dust seals and fittings for pressure grease lubrication.
2.9.18.3 Type C - Tilt Type Presence Indicator
Conical steel float that shall be tilted by presence of coal. Unit shall consist of housing, conical float,
universal pivot-collar, pendant mechanism, dust seal, limit switches, wiring, and mounting brackets. Unit shall
operate so that the tilting of the float actuates a limit switch in the enclosed housing above. Provide a hood
constructed according to manufacturer's recommendations for the indicator's location of not less than 5 mm 3/16
inch thick steel plate. Provide access panel for servicing the unit. Tilt type indicator may be a totally enclosed
type in which tilting causes a ball to roll off the center actuating a limit switch. Design unit to be cable
hung and to tilt on the presence of coal. Type and number of contacts and voltages shall be as indicated on
the control diagram.
2.9.18.4 Type D - Rotating Type Presence Indicator
Rotating paddle where presence of coal stalls motor and actuates a limit switch. Unit shall have either cast
iron or cast aluminum housing, stainless steel paddle, couplings, and flexible shaft. Shaft seal shall be spring
loaded and shall prevent the buildup of fines between shaft and hub. Operation shall be such that when paddle
stalls, motor continues to operate until the limit switch is actuated, which in turn shuts off the current to
the motor. Vane and baffle arrangements shall be according to manufacturer's recommendations for each indicator
location. Type and number of contacts and voltages shall be as indicated on the control diagrams.
2.9.18.5 Type E - Vibrating Type Presence Indicator
Vibrating sensing rod so that the presence of coal dampens the vibrations actuating a control signal. Sensing
rod shall be stainless steel not less than 10 mm 3/8 inch in diameter. Control unit shall be solid state, with
type and number of contacts and voltages as indicated on the control diagrams.
2.9.18.6 Equipment Speed Response Switch
Actuates a control signal when preset abnormal equipment operating conditions are encountered. Switch shall
be adjustable so that it may be used as an underspeed switch, overspeed switch, or zero speed switch. Switch
shall consist of input shaft from which the equipment speed is measured and compared to a preset point. Enclosure
shall be cast iron or suitably protected cast aluminum. Mount speed response switches as indicated on drawings.
Type of switch adjustment, type and number of contacts, and voltages shall be as indicated on the control diagrams.
2.9.18.7 Presence Indicators and Response Switches
Provide at hoppers and conveyor discharges located and protected according to manufacturer's recommendations
to ensure safe and reliable operation. Mount presence indicators in such a manner that they will not be injured
by occasional large lumps nor falsely operated by stray lumps or collected amounts of coal.
2.9.19 Control Panel and Controls
Provide a semi-automatic control system for the coal handling system as indicated. Control panel NEMA 12 construction,
centrally located in the main plant control room. Panel front shall include a system graphic display as indicated.
Display shall be approximately to scale and painted with an industrial acrylic enamel. Outline items with 3
mm 1/8 inch wide black lines. Lettering shall be on engraved plastic screwed to the front of the panel, with
white letters on a black background. Provide controls for operation on [_____] volt, [_____] phase, 60 Hz a.c.
Panel shall be complete with an annunciator and interlocks, relays, switches, running and safety lights, and
auxiliary parts necessary to safely control and operate the system. Items located in the door shall be dust-tight
and oil tight with push-to-test indicating lights being of the transformer type. Control relays shall be 10
amp, 600 volt class with convertible contacts. Provide and mark terminals for connections with the exception
of the neutral. Panel shall contain [_____] percent spare terminals. Wiring shall be No. 14 AWG type THHN stranded.
Neutral wire shall be white and other wiring of 120 volts or less shall be color coded and labeled. Provide
a plastic wire duct of sufficient size to provide [_____] percent cross sectional spare. Wiring shall be in
accordance with requirements of NFPA 70.
2.9.19.1 Panel Devices
Control panel shall include the following indicating lights (color in parenthesis):
a. Power - ON (red)
b. System Run (3 required)
Rail unloading hopper to storage yard (green)
Reclaim hopper to boiler plant (green)
Bunker to boiler plant (green)
c. Rail unloading hopper surfactant sprays - ON (green)
d. Reclaim hopper surfactant sprays - ON (green)
e. Stackout tube belt conveyor - ON (green)
f. Reclaim belt feeder - ON (green)
g. Bunker rotary vane feeder - ON (green)
h. Bunker reclaim belt feeder - ON (green)
i. Bucket elevator - ON (green)
j. Bunker - HIGH LEVEL (green)
k. Bunker - LOW LEVEL (red)
l. Screw conveyor no. 1 - ON (green)
m. Screw conveyor no. 2 - ON (green)
[n. Stoker surge hopper no. 1 inlet valve - OPEN (green)]
[o. Stoker surge hopper no. 2 inlet valve - OPEN (green)]
p. Emergency discharge chute - OPEN (green)
q. Stoker surge hopper - HIGH LEVEL (one required for each hopper)
r. Stoker surge hopper - LOW LEVEL (one required for each hopper)
s. Stoker surge hopper - LOW LOW LEVEL (one required for each hopper)
[t. Coal scale - ON (green)]
2.9.19.2 Switches and Pushbuttons
Provide momentary contact pushbuttons or selector switches for the following:
a. System- START (3 required)
Rail unloading hopper to storage yard
Reclaim hopper to boiler plant
Bunker to boiler plant
b. System - STOP (red head)
c. Rail unloading hopper surfactant spray - START/STOP
d. Reclaim hopper surfactant spray - START/STOP
e. Alarm - ACKNOWLEDGE
2.9.19.3 Annunciator Panel
Annunciator panel shall include the following:
a. Bunker - HIGH LEVEL
b. Bunker - LOW LEVEL
c. Stoker surge hopper (one required for each hopper) - HIGH LEVEL
d. Stoker surge hopper (one required for each hopper) - LOW LEVEL
e. Stoker surge hopper (one required for each hopper) - LOW LOW LEVEL
f. EMERGENCY SHUTDOWN (Auxiliary contacts for remote alarm)
g. Blank (3 required)
2.9.19.4 Panel Size
Size panel to accommodate future addition of one stoker surge hopper and associated equipment.
2.9.19.5 Auxiliary Devices
Provide auxiliary devices required for the control functions indicated above.
2.9.19.6 Name Plates
Provide laminated plastic name plates for devices on panel face.
2.9.19.7 Control Sequence
To ensure that coal does not back up during system startup or shutdown, design the controls so that on startup,
the last piece of equipment to handle coal starts first and on shutdown, stops last.
2.9.19.8 Additional Controls
Provide as shown. These controls include local START and STOP pushbuttons or three-position selector switches
for the following:
a. Belt feeders
b. Rotary vane feeder
c. Belt conveyor (at head pulley)
d. Screw conveyors
[e. Coal scale]
f. EMERGENCY STOP pushbuttons which stop the entire system shall be provided where indicated.
2.9.20 Multiple Belt Scrapers
Equip conveyor belts at the head pulley, with multiple belt scrapers. Adequate room and service access shall
be provided in the head chute design for multiple cleaners. Provide a doctor blade on the face of the head pulley
to remove most of the carryback material and a torsion arm type multiple blade cleaner to scrape and remove material
that bypasses the primary cleaner. Tail pulley takeups shall be provided with a plow to protect against material
being carried back between the belt and the pulleys. Both cleaners and plows shall have features that enable
the operator to safely inspect and adjust blades. Dribble chutes shall be designed to resist material buildup
and shall be plastic lined. A convenient dust tight door for clean out and inspection purposes shall be provided
on each side of the dribble chute.
2.9.21 Steel Coal Bunker
Cylindrical shaped type having a storage capacity of not less than [_____] Mg tons of coal having a density of
800 kg per cubic meter 50 pounds per cubic foot.
2.9.21.1 Construction
Welded construction, not less than [_____] meters feet in diameter with a vertical cylindrical section [_____]
meters feet [_____] mm inches high. Construct vertical cylindrical section of not less than 7.94 mm 5/16 inch
thick steel plate. Slope bottom cone shaped hopper section at not less than 55 degrees and fabricate from not
less than 10 mm 3/8 inch thick 410 stainless steel plate. Top of bunker shall be conical 35 degree sloped structurally
reinforced 6 mm 1/4 inch thick steel plate. Provide ladder inside bunker and immediately above ladder the bunker
top shall contain dusttight, weather tight access hatch of not less than 610 by 610 mm 24 by 24 inches. Shell
and bottom plates shall be beveled for full butt weld on inside of bunker and a finish weld on outside of bunker.
Provide bunker with flanged outlet drilled to match inlet of gate.
a. Responsibility: Contractor with whom contract is drawn shall assume full responsibility
for the design and final details of construction of the steel coal bunker.
b. Supports: Bunker shall be self supporting from four steel columns which shall be supported
from on top of a concrete foundation. Concrete work shall be as specified in Section
03 30 00 CAST-IN-PLACE CONCRETE.
c. Liner: Surface blast vertical inside surfaces of the bunker to a near white metal, and
then coat with 6 mm 1/4 inch thick troweled-on heavy duty three compound corrosion resistant
liner consisting of a resin, a hardener and graphite aggregate. Liner shall have an operating
temperature limitation of not less than 66 degrees C 150 degrees F.
2.9.21.2 Accessories
a. Alarm Switches: Provide bunker with two automatic bin level indicators with neoprene rubber
diaphragm and a single pole, double throw switch mounted in explosion proof aluminum housing
to signal high and low level alarms. Provide mounting plates on bunker shell and holes for
installation of indicator housing on outside of bunker. Wiring shall be as specified in
26 11 16 SECONDARY UNIT SUBSTATIONS.
b. Vibrators: Provide on the cone bottom of the coal bunker a heavy duty pulsating magnet
electric vibrator, semi-noiseless type, complete with mounting plate. Provide one vibrator
controller panel arranged for mounting in wall mounted control panel. Panel shall contain an
"ON-OFF" switch, power control dial, fuses and rectifier. Power supply to panel shall be 460
volt, single phase, 60 Hz current.
2.9.22 Stoker Surge Hoppers
Construct stoker surge hoppers dusttight approximately as indicated of 6 mm 1/4 inch, 410 stainless steel plate
with structural stiffeners, to hold not less than [_____] Mg tons of coal at a density of 800 kg per cubic meter
50 pounds per cubic foot. Connection transition between surge hopper discharge chute and stoker hopper extension
shall have bolted emergency firing door of not less than 610 by 457 mm 24 by 18 inches which shall contain a
150 by 150 mm 6 by 6 inch glass observation window. Connections shall be dusttight.
2.9.23 Coal Meter
Vane type, where a direct readout counter is directly connected by a flexible shaft to a vane projected into
center of coal downspout.
2.9.23.1 Vane
Construct vane of stainless steel design so that each foot of coal travel in the downspout causes the vane to
turn a definite amount.
2.9.23.2 Counter
Counter shall have not less than four 25 mm one inch high figures on translucent material, illuminated from within
the counter. Counter shall record directly the number of pounds of coal passing through the downspout.
2.9.24 Stackout Tube
Provide a stackout type discharge tube not less than 10 mm 3/8 inch thick, reinforced, stainless steel plate
for discharging coal from the stackout conveyor to the coal storage yard. Tube shall be 1220 mm 4 feet 0 inches
in diameter, and shall be designed as the structural support for a portion of the stackout conveyor and support
steel as indicated on the drawings. Tube shall be a window chute designed to discharge coal at not more than
1.83 meters 6 feet above coal pile.
2.10 FUEL OIL SYSTEM
NOTE: In reference to the following text, choose Section 33 56 10 FACTORY-FABRICATED
FUEL STORAGE TANKS if specifying below grade level fuel oil tanks. The rest
of the system (including above ground tanks) shall be constructed to Section
33 52 10 SERVICE PIPING, FUEL SYSTEMS.
The fuel oil system shall be designed and built in accordance with Section 33 52 10 SERVICE PIPING, FUEL SYSTEMS[.][,
except when underground fuel oil tanks are specified. Below grade level fuel oil tanks shall be constructed
in accordance with Section 33 56 10 FACTORY-FABRICATED FUEL STORAGE TANKS.]
2.11 ASH HANDLING SYSTEM (MECHANICAL)
NOTE: Choose this article and its paragraphs and subparagraphs or the following
article entitled "Ash Handling System (Pneumatic)" and its paragraphs and subparagraphs.
2.11.1 General
2.11.1.1 System Requirements
Provide a complete integrated, mechanical, semi-automatic, ash handling system with chain drag conveyor, screw
conveyors, bucket elevator, material intakes, rotary valves, [ash doors and enclosures,] silo vent filter, ash
silo, rotary ash conditioner, and additional equipment required for a complete mechanical ash handling system.
Provide related electrical work required to operate the ash handling system.
2.11.1.2 Routing
The system shall receive, and convey to the ash silo, ash from the stoker fired boiler ash storage pits, [economizer
hoppers,] [baghouse hoppers,] and other pollution control equipment hoppers.
2.11.1.3 Discharge
Discharge ash into ash storage silo in a dry condition. Arrange silo equipment for disposal of conditioned ash
to trucks. Operation shall be as dustless as possible.
2.11.1.4 Maximum Noise Level
Noise level of the operation shall not exceed 85 decibels sound pressure level 1.52 meters 5 feet from the equipment
in any direction.
2.11.2 System Valving
2.11.2.1 Rotary Valves
Provide rotary valve feeders of carbon steel construction complete with drive, guard, motor mount and gaskets,
carbon steel adjustable blade tips, adjustable shoe type air seal and right angle gearhead drive motor. Rotor
blade tips and shoes shall have a minimum Brinnell hardness of 500. Valves requiring part of the housing to
form an airlock seal are not acceptable.
a. Electric Motor: Totally enclosed, fan cooled, [_____] volt, [_____] phase, 60 Hz not less
than [_____] kW hp as specified under paragraph entitled "Motors and Drives" in this section.
2.11.2.2 Manual Valve Intakes for Bottom Ash
Provide in front of the stoker ash pit doors a 610 by 610 mm 24 by 24 inch cast iron grid and hopper with opening
approximately sized for the conveyor. Provide intake with dusttight, removable 6 mm 1/4 inch thick checkered
steel plate cover.
2.11.2.3 Silo Discharge Valve
Provide a rotary feeder for discharging bottom ash and fly ash from the ash silo. Feeders shall be of ductile
iron or cast steel and shall be complete with motor, motor support, chain drive, and necessary guards. Chain
shall be driven through a torque limiting clutch on the driven sprocket equipped with electric cutout switch
and alarm. [Feeder shall have spring-loaded hinged bypass plate to permit passage of clinkers.] Inlet and outlet
flanges shall be standard drilled pipe flange. Rotor blades and sealing arrangement shall be the manufacturer's
standard for the intended service. When rotors are equipped with adjustable tips, provide a service door in
the body of the valve for tip adjustment. Shaft seals shall be of the packing gland type with suitable packing
materials. Shaft bearings shall be outboard sealed ball bearings. Periphery seals shall be such that a complete
seal is accomplished at a differential of [_____] Pa inches of water static pressure.
2.11.3 Conveyors
2.11.3.1 Chain Drag Conveyor
Provide endless chain for dragging coal ashes from front of boilers along a recessed trough to the inlet chute
of a bucket elevator. Conveyor shall have [_____] meters feet sprocket centers, operate at speed not greater
than 35 mm per second 7 feet per minute, and have a capacity of not less than [_____] Mg per hour of 640 kg per
cubic meter tons per hour of 40 pounds per cubic foot ash. Provide conveyor complete with continuous chain,
drive, and take up terminals, gears, shafts, bearings, return rolls, hard white iron trough, ash intake gratings,
floor plates, discharge chute, electric motor, reduction gear, and supports. [Chain drag conveyor shall be designed
for future length of [_____] meter feet.]
a. Head and Foot Shafts: Provide SAE 1045, steel head and foot shafts not less than [_____]
and [_____] mm inches in diameter, respectively, mounted in anti-friction roller bearings in
pillow blocks. Foot shaft shall have screw-type takeups with not less than [_____] mm inches
adjustment.
b. Terminal Sprockets: Terminal sprockets shall be gray iron chilled rim not less than [_____]
mm inches in diameter with solid web and not less than eight teeth each.
c. Chain: Combination drag type of riveted construction. Design chain symmetrically so that
it can be turned over after one side is worn. Chain shall be [_____] mm inches wide with a
pitch not greater than 200 mm 8 inches and an ultimate strength of not less than [187] [249]
kN [42,000] [56,000] pounds. Construct chain of promal, a pearlitic malleable iron, center
links not less than [_____] mm inches high, and heavy [_____] mm inch thick heat treated carbon
steel side bars. Steel pins shall be cold rolled steel not less than [_____] mm inch in diameter,
press-fitted into sidebars, and machined flat on one side to prevent rotation. Center section
shall be rugged block type forming a rigid rectangle for maximum resistance to distortion with
broad wearing shoes contoured to prevent snagging and damage to chain or trough. Barrels of
center section shall be chambered to provide lubricant reservoir and still provide maximum bearing
area for pins. Shape barrel with pushing surface on one side and for contact with sprocket
on the other side.
d. Trough: Concrete lined with not less than [_____] mm inch thick hard white iron approximately
as indicated. Trough shall be [_____] mm inches wide with hinged 6 mm 1/4 inch thick checkered
steel plate covers. Covers shall be installed to be dusttight. Coordinate concrete work with
conveyor manufacturer's requirements.
e. Return Rollers: Chilled rim, single flange, enclosed-oiling type on [_____] mm inch diameter
carbon steel shafts spaced at not more than 3 meters 10 feet apart.
f. Discharge Chute: Construct of not less than 10 mm 3/8 inch steel plate and slope at not
less than 60 degrees.
g. Electric Motor and Drive: Totally enclosed, fan cooled, high torque, [_____] volt, [_____]
phase, 60 Hz not less than [_____] kW hp as specified under paragraph entitled "Motors and Drives"
in this section, direct connected by means of flexible coupling to a reduction gear unit having
alloy steel helical or herringbone gears and antifriction bearings enclosed in oiltight housing.
Provide an adjustable base for motor and reduction gear. Drive from output shaft of the reduction
gear to the conveyor head shaft shall be by means of finished steel roller chain conforming
to ASME B29.100 running over cut tooth sprockets conforming to ASME B29.100 complete with steel
plate chain guard. Roller chain attachments shall conform to ASME B29.100.
2.11.3.2 Screw Conveyors
Provide each screw conveyor dusttight and furnished complete, with trough, screw, inlet and discharge spouts,
discharge gates, bearings, bearing hangers, dust cover, electric motor, reduction gear, [service platform,] and
supports.
2.11.3.3 Inlet and Discharge Spouts
Arrange as indicated. Spouts shall be flanged and square with opening dimensions equal to the inside diameter
of the trough.
2.11.3.4 Screw Trough
Provide dusttight screw trough with trough covers. Support trough by 6 mm 1/4 inch thick steel plate feet at
not less than 3 meters 10 foot intervals. Individual trough sections shall not be greater than 3 meters 10 feet
long with steel angle end flanged connections.
2.11.3.5 Bearings and Hangers
Provide thrust bearings and trough end dust seals for both drive and tail bearings. Thrust bearings shall be
bronze in antifriction pillow blocks. Screw hanger bearings shall be babitted-type, with cast iron hangers
having removable bearing caps held in place by a U-bolt. Design hangers to fit inside the conveyor trough and
equip bearings for grease lubrication with grease fittings penetrating the dust cover to allow bearings to be
greased without removing dust cover. Hangers shall not be located at trough joints, feed, or discharge openings.
Locate hangers at not less than [3.66 meter12 foot intervals for screw diameters larger than 250 mm 10 inches
] [and] [3 meters10 foot intervals for screw diameters 250 mm 10 inches in diameter and smaller].
2.11.3.6 Conveyor Screws and Couplings
Construct conveyor screws of helocoid-type flights and connect with cold rolled steel couplings. Assemble conveyor
screws so that at the hangers there is 180 degrees rotation between the flight ends of each adjacent screw section.
Screw flight shall end over last discharge spout so bare pipe extends across this area to prevent material carry-over.
2.11.3.7 Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, three phase, 60 Hz, not less than [_____] kW hp as specified
under paragraph entitled "Motors and Drives" in this section. Install motor at discharge end of the conveyor.
Motor shall be supported by a unit bracket attached to the screw conveyor trough end plate and shall be connected
to reduction gear through a V-belt drive. Reduction gear shall be shaft mounted, double reduction type mounted
directly on the conveyor shaft. Provide tie rods, when required, to prevent reduction gear rotation and for
adjusting belt tension.
2.11.3.8 Service Platforms
Provide service platform conforming to OSHA regulations as indicated to properly maintain and service conveyor
drive unit.
2.11.4 Bucket Elevator
Provide a dusttight bucket elevator centrifugal discharge type, having approximately [_____] meter foot [_____]
mm inch sprocket centers, vertical chain and bucket, operating at a speed not to exceed [_____] meters per second
(m/s) feet per minute (fpm), and having a capacity of not less than [_____] Mg per hour of 640 kg per cubic meter
tons per hour of 40 pounds per cubic foot ash. Provide bucket elevator complete with continuous chain and attached
buckets, sprockets, gears, shafts, bearings, casing, top hood, discharge spout, bottom boot, access doors, electric
motor, reduction gear, service platform, and accessories.
2.11.4.1 Head and Foot Shafts
Head and foot shafts shall be not less than [_____] and [_____] mm inches in diameter, respectively. Construct
shafts of cold rolled steel and mount in antifriction roller bearings with forced lubricating type fittings.
Mount foot shaft in fixed pillow blocks. Head shaft shall have screw-type takeups with not less than [_____]
mm inches adjustment.
2.11.4.2 Terminal Sprockets
Cast iron with chilled rims. Head sprocket shall be not less than [_____] mm inches in diameter and foot sprocket
not less than [_____] mm inches in diameter.
2.11.4.3 Buckets and Chain
Construct buckets of malleable iron not less than 200 mm long, 127 mm wide, 140 mm deep 8 inches long, 5 inches
wide, and 12 inches deep. Buckets shall be mounted by not less than four bolt attachments to a single strand
of steel bushed chain having an ultimate strength of not less than 178 kN 40,000 pounds and pitch of 100 mm 4
inches. Bucket spacing shall be not greater than 406 mm 16 inches.
2.11.4.4 Backstop
Differential band brake type to prevent reversal of chain and buckets in case of power failure.
2.11.4.5 Casing
Elevator casing shall be not less than 298 by 991 mm 11 3/4 by 39 inches inside and constructed of not less than
5 mm 3/16 inch thick commercial hot rolled mild steel plate with 50 by 50 by 6 mm 2 by 2 by 1/4 inch corner
angles for full height of elevator casing. Fabricate casing in standard sections from 250 to 300 meter high
with 50 by 50 by 6 mm 10 to 12 feet high with 2 by 2 by 1/4 inch angles at both flanges for each section. Provide
a hinged inspection door not less than 610 by 762 mm 24 by 30 inches in the section immediately above the boot
section and at other indicated points. Casing and inspection doors shall be of dusttight construction with flange
angles continuously welded and gasketed. No makeshift repairs or field patching to overcome leakage shall be
permitted. Give casing interior a 1.60 mm 1/16 inch thick coating of coal tar primer and enamel conforming to
SSPC PS 11.01.
2.11.4.6 Head Section
Construct of not less than 5 mm 3/16 inch thick commercial hot rolled mild steel plate in heavy angle frame with
split, hinged, and removable top cover hood built of not less than 10 gage (3.42 mm0.1345 inch) commercial hot
rolled mild steel plate and flanged discharge throat built of not less than 5 mm 3/16 inch commercial hot rolled
mild steel plate. Design head section to support the drive machinery and head bearings. Provide access ladder
and service platform conforming to applicable OSHA regulations as indicated for providing proper service and
maintenance of elevator.
2.11.4.7 Boot Section
Construct of not less than 5 mm 3/16 inch commercial hot rolled mild steel plate in heavy angle frame with curved
and renewable bottom plate and renewable internal loading leg, both built of not less than 5 mm 3/16 inch commercial
hot rolled mild steel plate, and flanged inlet. Mount take-up and foot terminal bearing on one side of the boot
in a bolted removable side panel so the foot shaft and sprocket may be removed through the side of the door.
Bolt end panels so they are removable for cleanout and inspection.
2.11.4.8 Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, three phase, 60 Hz, not less than [_____] kW hp as specified
under paragraph entitled "Motors and Drives" in this section, direct connected by means of flexible coupling
to a reduction gear unit having alloy steel herringbone or helical gears and antifriction bearings enclosed in
oiltight housing. Provide an adjustable base for motor and reduction gear unit. Drive from the output speed
shaft of the reduction gear to the elevator head shaft shall be by means of finished steel roller chain conforming
to ASME B29.100 running over cut tooth sprockets conforming to ASME B29.100 complete with steel plate chain guard.
Roller chain attachments shall conform to ASME B29.100.
2.11.4.9 Anchoring Brackets
Provide steel brackets as indicated at intervals for anchoring elevator to increase rigidity.
2.11.4.10 Discharge Chute
Construct discharge chute to ash silo of not less than 10 mm 3/8 inch thick steel plate.
2.11.5 Ash Storage Silo
[_____] meters feet in diameter with [_____] meters feet high walls with a live bottom and flyash storage capacity
of not less than [_____] Mg tons, based on ash bulk density of 640 kg per cubic meter 40 pounds per cubic foot
for volumetric sizing. Structural joints shall be dusttight and watertight. Provide columns, beams, bracing,
and other structural members as required for complete erection of silo and accessories. Live storage capacity
shall allow for 20 degree angle of repose from silo outlet. Height of silo storage shall not be more than twice
the diameter. Provide a minimum of one meter 3 feet of freeboard above the ash level. Design of support steel
shall be approved by the ash system supplier. Design silo in accordance with the Uniform Building Code. The
design shall take into account seismic load, wind load, snow load, equipment loads and an ash bulk density of
1120 kg per cubic meter 70 pounds per cubic foot. Ash silo support shall be free standing and shall be of sufficient
height to allow gravity discharge of ash through the rotary ash conditioner to a [truck] [railroad car]. Provide
access to the stair tower with intermediate platforms at 3.66 meters 12 feet intervals which access the ash conditioner
level, silo floor level and silo roof level. Platforms from adjacent structures with stair access may be provided
in lieu of the stair tower, but ladders with safety cages and access platforms must be additionally provided.
Provide ladder with stainless steel fall prevention device on inside of silo from manhole in top of silo to bottom
of silo. [Provide silo roof enclosure and unloader room enclosure each with a single one by 2 meters 3 by 7
foot access door, [_____] by [_____] meter foot double door, two windows, ventilator, [heater], insulated metal
panel siding to match boiler plant walls and electrical lighting and convenience receptacles. Unloader room
enclosure shall have reinforced concrete floor.]
2.11.5.1 Construction
Construct silo of steel with refractory lining or of concrete staves with steel hoops and concrete roof. Roof
accessories shall include manhole, relief valve and vent filter. Bottom of silo shall be [conical, sloped a
minimum of 45 degrees.] [flat with a steel plate feeding hopper in bottom of silo to funnel the ash into the
inlet of the rotary vane feeder.] Provide hopper with expansion joints and sufficient poke holes with cover or
cap.
2.11.5.2 Concrete Stave Silo
Construct concrete stave silo of either lightweight solid or hollow precast concrete staves with post-tensioned
steel reinforcing hoops around the exterior. Mechanically measure and mix materials in concrete staves. Vibrate
and shape staves under pressure and steam or air cure.
a. Wall Coating: Coat interior surface with a three-step process of a brush coat, scratch
coat, and finish trowel coat of a mixture of fine sand and portland cement in accordance with
silo manufacturer's recommendations. Apply each coat successively to produce a smooth interior
surface. Work mixture into the formed horizontal and vertical grooves to permanently interlock
the concrete staves. Brush coat the exterior surface with a double application of waterproof
mixture. Mixture shall include a chemical agent for waterproofing and portland cement, sand,
and water. Work coating into joints and over the steel reinforcing hoops to form a weatherproof
protective coating.
b. Steel Reinforcing Hoops: Galvanized steel rods not less than 14 mm 9/16 inch in diameter
with not less than 16 mm 5/8 inch rolled threads. Join hoop ends together with nuts and heavy
malleable galvanized iron lugs or heavy duty galvanized steel lugs to a close tolerance for
a tight fit. Electrogalvanize rods, nuts, and lugs to ensure adequate protection against corrosion.
Rods shall be high quality, metallurgically sound steel with tensile strength not less than
448 MPa 65,000 pounds per square inch (psi), yield point not less than 276 MPa 40,000 psi, and
a minimum elongation of 14 percent in 229 mm 9 inches. Reinforcing shall be sufficient to resist
the maximum lateral pressure and loads imposed by the ash pressure within the silo. Hoop rods
shall be structurally connected together where they pass through silo outlets on inspection
frames.
c. Hollow Concrete Stave Silos: Construct silo of precast concrete staves with lateral air
spaces. Cast staves from a well proportioned mix of portland cement and an expanded clay light
weight aggregate. The minimum compressive strength of the concrete at 28 days shall be 34.50
MPa 5,000 psi. Hollow staves shall be 92 mm thick by 250 mm wide by 762 mm long 3 5/8 inches
thick by 10 inches wide by 30 inches long with five lateral air cores per stave, except that
shorter starter staves may be used to permit the horizontal joints to be staggered.
d. Solid Concrete Stave Silos: Construct silo of solid lightweight precast concrete staves.
Solid staves shall be not less than 92 mm thick and 250 mm wide by 762 mm long 3 5/8 inches
thick and 10 inches wide by 30 inches long, except starter staves may be shorter. Solid staves
shall be constructed from a well proportioned mix of portland cement, washed sand and gravel
which is free from injurious organic impurities and contains less than 5 percent of deleterious
substances. Grade fine aggregate from coarse to fine. Compressive strength of solid concrete
staves at 28 days shall be 34.50 MPa 5,000 psi.
2.11.6 Pulse Jet Bag Filter Vent
Provide for the silo constructed of 10 gage steel plate, fitted with rain hood. Bag material shall be sateen
cotton capable of withstanding not less than 91 degrees C 195 degrees F, weighing 0.33 kg per square meter 9.75
ounces per square yard, having thread count of 4 by 2 per square mm96 by 60 per square inch and permeability
of 76 to 102 L/s per square meter at 249 Pa 15 to 20 cfm per square foot at one inch water column. Vent shall
have not less than [_____] square meter feet effective cloth filtering area, with each bag having a maximum effective
cloth filtering area of 0.56 square meter 6 square feet.
2.11.7 Rotary Ash Conditioner (Unloader)
Provide a complete dustless horizontal, floor mounted unloading device to discharge ashes from silo to a [truck]
[railroad car]. Unloader (ash conditioner) shall include a 762 mm 30 inch diameter revolving drum which rotates
about fixed spray nozzles, and shall be complete with conditioner and discharge compartments, scrapers, and other
accessories as required. Unloader drum shall be constructed of steel plate not less than 10 mm 3/8 inch thick
and shall be roller chain driven by a totally enclosed, fan cooled, [_____] volt, three phase, 60 Hz electric
motor not less than 3.75 kW 5 hp as specified under paragraph entitled "Motors and Drives" in this section.
Unloader shall discharge the conditioned ashes to a truck through a 6 mm 1/4 inch thick steel plate chute. The
unloader shall be designed to eliminate most dust in unloading ash from the ash silo. An unloader that utilizes
screws as a means of mixing is unacceptable. The dustless unloader shall add water to the ash, but not to the
extent that there is free or surplus water running or dripping from the ash after discharge. Discharge ash shall
be in a semi-fluid, loose, free flowing condition.
2.11.8 Fluidizing System
Provide on the silo floor to ensure a constant and uniform feed of ash through the silo discharge outlet. System
shall consist of a series of diffuser modules, a conical diffuser hood, designed to support the total weight
of ash when the silo is full, and compressed air piping. Each diffuser module shall be mounted on the silo floor
using sloped concrete pads. System shall operate from the plant air system. Provide pressure reducing valves,
safety valves, and controls for a complete system.
2.11.9 Control Panel and Controls
Provide a semi-automatic control system for the ash handling system [as indicated]. Provide a centrally controlled
operation, with auxiliary local operation, and a monitoring control system with graphic display for the ash conveying
system. Provide local control stop-start pushbuttons and indication stations for chain drag conveyor, screw
conveyors, bucket elevator, and rotary ash conditioner. Ash handling system manufacturer shall provide measuring
devices, status switches, solenoid valves, and auxiliary parts necessary to safely control and operate the system.
Provide related electrical work required to operate the ash handling system. [Ash handling system manufacturer
shall provide detailed control logic diagrams to the manufacturer of the digital process control and data acquisition
system specified under VAMS Section 23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT.]
2.11.9.1 Control Panel
Provide a [separate control panel] [subpanel mounted in the main plant control panel] of NEMA 12 construction,
centrally located in the main plant control room. Panel front shall include a system graphic display as indicated.
Display shall be approximately to scale and painted with an industrial acrylic enamel. Outline items with 3
mm 1/8 inch wide black lines. Lettering shall be on engraved plastic screwed to the front of the panel, with
white letters on a black background. Provide controls for operation on [_____] volt, [_____] phase, 60 Hz a.c.
Panel shall be complete with an annunciator and interlocks, relays, switches, running and safety lights, and
auxiliary parts necessary to safely control and operate the system. Items located in the door shall be dusttight
and oil tight with push-to-test indicating lights being of the transformer type. Control relays shall be 10
amp, 600 volt class with convertible contacts. Provide and mark terminals for connections with the exception
of the neutral. Panel shall contain [_____] percent spare terminals. Wiring shall be No. 14 AWG Type THHN
stranded. Neutral wire shall be white and other wiring of 120 volts or less shall be color coded and labeled.
Provide a plastic wire duct of sufficient size to provide [_____] percent cross sectional spare. Wiring shall
be in accordance with the requirements of NFPA 70.
2.11.9.2 Control Panel Devices
a. Control panel shall include the following indicating lights (color in parentheses):
(1) Power - ON (red)
(2) System Run (3 required)
Chain drag conveyor to elevator (green)
Screw conveyors to drag conveyor (green)
Bucket elevator to silo (green)
(3) Ash Silo - HI LEVEL (red)
(4) Ash Silo - LOW LEVEL (red)
(5) Silo Vent Filter - ON (green)
b. Provide momentary contact pushbuttons or selector switches for the following:
(1) System - START (3 required)
Bucket elevator
Chain drag conveyor
Screw conveyors
(2) System - STOP (red head)
c. Provide sensors such that the following items can be alarmed on an ash handling system control
panel annunciator.
(1) Ash silo - HIGH LEVEL
(2) Bucket elevator - EMERGENCY SHUTDOWN
(3) Screw conveyor - EMERGENCY SHUTDOWN
(4) Chain drag conveyor - EMERGENCY SHUTDOWN
(5) Silo vent filter - OFF
(6) Plugged Hopper
d. Provide auxiliary devices required for the control functions above and laminated plastic
name plates for devices on the panel front.
e. Provide local control panel for operating and indication of the rotary ash conditioner with
the following functions:
(1) Power - ON (red)
(2) Water - ON/OFF
(3) Ash feeder - ON/OFF
(4) Rotary ash conditioner - START/STOP/JOG
(5) Normal Stop
(6) Wash out - START/STOP
(7) Emergency Stop
f. Provide control panel mounted at grade level for remote operation of the rotary ash conditioner
with the following functions:
(1) Rotary ash conditioner - START/STOP
(2) Normal stop
(3) Emergency stop
2.12 ASH HANDLING SYSTEM (PNEUMATIC)
NOTE: Choose this article and its paragraphs and subparagraphs or the above
article entitled "Ash Handling System (Mechanical)" and its paragraphs and subparagraphs.
2.12.1 System Requirements
Provide a complete integrated, pneumatic, automatic sequencing, ash handling system with air intakes, material
intakes, ash doors and enclosures, iron alloy conveyor line, fittings, rotary slide gates, primary and secondary
materials separators, tertiary bag filter, [steam exhauster,] [electric motor driven positive displacement blower
(mechanical exhauster),] [air washer,] silo vent filter, ash silo, rotary ash conditioner, and any other equipment
that may be necessary for a complete pneumatic ash handling system. Provide related electrical work required
to operate the ash handling system. Design system so that the ash silo is never placed under a partial vacuum.
2.12.2 System Type
System shall be of the intermittent vacuum type, whereby the vacuum is interrupted permitting periodic discharge
of collected materials into the silo on a programmed time cycle. System shall have sufficient air velocity to
pick up ash that may be deposited in the pipe.
2.12.3 Hoppers
System shall receive, and on a sequenced basis convey to the ash silo, ash from the stoker fired boiler ash storage
hoppers, siftings hoppers, soot hoppers, baghouse hoppers, and other pollution control equipment hoppers. Convey
from only one pickup point at a time.
2.12.4 Discharge
Discharge ash into the ash storage silo in a dry condition. Arrange silo equipment for disposal of conditioned
ash to trucks. Operation shall be as nearly dustless as possible.
2.12.5 Maximum Noise Level
The noise level of the operation shall not exceed 85 decibels sound pressure level 1.52 meters 5 feet from the
equipment in any direction.
2.12.6 Ash Storage Hopper
Provide a dry storage hopper for each boiler to receive and store bottom ash as it is discharged from the traveling
grate. Hopper shall be compatible with the grate ash discharge enclosure as specified under paragraph entitled
"Coal Stokers" and shall have a net volume to receive and store material for an 8 hour period at maximum boiler
output. Size hopper for mean ash level for one meter 3 feet below the step floor with ash density of 640 kg
per cubic meter 40 pounds per cubic foot for volumetric sizing.
2.12.6.1 Construction
Not less than 6 mm 1/4 inch thick, ASTM A 36/A 36M, steel plate, dust tight, floor supported steel structure
with refractory lining. Provide required steel columns, beams stiffeners and cross bracing. Bolt top section
of the hopper to the stoker support steel. Design load of hopper shall be based on 1120 kg per cubic meter 70
pounds per cubic foot. Slope sides at not less than 45 degrees from the horizontal to maintain positive feed
to the outlet.
2.12.6.2 Refractory Materials
As recommended by the manufacturer; the minimum total thickness of the refractory and insulating block lining
shall not be less than 178 mm 7 inches. Refractory shall be minimum of 114 mm 4 1/2 inches.
2.12.6.3 Discharge Doors or Gates
Provide each hopper with refractory lined, dust tight, water cooled, vertical lift doors, of an opening size
not less than 560 by 560 mm 22 by 22 inches. Each door shall be [air-cylinder operated] [chain wheel operated].
[Provide intermediate positioning capability with air cylinder operators.] Provide each door with guide rollers
and support arms to ensure smooth operation without binding. When doors are vertical the minimum number of rollers
shall be 4; for a sloping surface, the minimum number of rollers shall be 6.
2.12.6.4 Hopper Lift Door Enclosure
Provide not less than 6 mm 1/4 inch thick steel, dust tight, enclosure, for each vertical lift door. Match enclosure
to housing of the clinker crusher and make it large enough to enclose the outlet and the vertical lift door.
Provide hinged inspection and cleanout door on the front of the enclosure.
2.12.6.5 Hopper Access Door
Provide hinged access door on one side wall of each hopper. Door shall be cast iron, air tight swing-away locking
type with refractory lining. Install door so that it is convenient and easy to use.
2.12.7 Clinker Crusher
Provide a clinker crusher mounted under each hopper discharge outlet, below the vertical lift door enclosure,
capable of reducing clinkers from bottom ash to a maximum size of 50 mm 2 inches at a rate not less than the
conveyer system capacity.
2.12.7.1 Construction
Single roller crusher unit with extra heavy housing, outboard bearings sealed against grit infiltration, motor
and drive. Housing shall be 15 mm 1/2 inch thick. Crusher rollers shall have replaceable cam segments (teeth)
with a minimum Brinell hardness of 450. Each cam tooth shall be designed to permit resurfacing with hard material.
Stationary heavy cast iron or manganese steel abrasion resistant wear plates, of a Brinell hardness not less
than 350, shall be mounted about the crusher rollers. Cam shaft rotational speed shall not exceed 20 rpm.
2.12.7.2 Fluid Gear Drive
Crushers shall be driven by a fluid gear drive including a totally enclosed, fan cooled, [_____] volt, three
phase, 60 Hz electric motor not less than 3.75 kW5 hp, as specified under paragraph entitled "Motors and Drives"
in this section, fluid coupling and reduction gear, integrally mounted in dust and oil tight enclosures. Fluid
drive shall protect the unit from excessive shock. Drive shall automatically reverse when stalled; crusher shall
reverse and move forward three times and, after the third time, shall shut down and alarm when still stalled.
2.12.8 System Valving
2.12.8.1 Side Intake Valve for Fly Ash
Provide side intake valve for fly ash collection at each hopper, including dust collection hoppers and rear pass
hoppers, and other collection points. Side intake valve shall be pneumatically opened, spring closed, totally
enclosed disc valve of cast iron construction with wearing surfaces of Brinell hardness not less than 350. Provide
valve complete with flanged inlet hopper, handhole with gasketed cover and clamp and couplings. Side intake
valve shall feed ash to conveyor line on an angle, thus permitting air to mingle with the ash in the proper proportion
to eliminate clogging. Valves shall provide positive and automatic air tight shutoff and dust tight pickup.
Valve shall close on failure of operating air and before the discharge cycle of the intermittent conveyor operation.
A full load regulating switch shall control each valve to prevent overloading of the conveyor system.
2.12.8.2 Rotary Valve Intakes for Bottom Ash
Provide a rotary valve, designed for regulating bottom ash to the a conveyor pipeline, under each crusher. Valve
shall provide intake isolation and prevent overfilling or plugging of the conveyor line. Construction of valve
shall be of cast iron with wearing surfaces of Brinell hardness not less than 350. Valve shall be pneumatically
operated.
2.12.8.3 Air Intake
Provide spring loaded, swing disc, check valve type air intake, designed for air induction, at the end of each
conveyor branch. When intake is located exposed to the weather, provide a rain hood.
2.12.8.4 Isolating Valves (Line Valves)
Provide an air operated, totally enclosed rotary slide gate isolating valve at each branch pipe line connection
to prevent air flow through an unused branch line. Construct valve of abrasion resistant metal, machined and
fitted to ensure a vacuum tight fit and guard against leakage and excessive maintenance. Provide purge air connection
and a solenoid valve in the valve housing or cavity for purging the gate cavity of ash.
2.12.8.5 Silo Discharge Valve
Provide a rotary feeder for discharging bottom ash and fly ash from the ash silo. Feeders shall be of ductile
iron or cast steel and shall be complete with motor, motor support, chain drive, and necessary guards. Chain
shall be driven through a torque limiting clutch on the driven sprocket equipped with electric cutout switch
and alarm. [Feeder shall have spring-loaded hinged bypass plate to permit passage of clinkers.] Inlet and outlet
flanges shall be standard drilled pipe flange. Rotor blades and sealing arrangement shall be the manufacturer's
standard for the intended service. When rotors are equipped with adjustable tips, provide a service door in
the body of the valve for tip adjustment. Provide packing gland type shaft seals with suitable packing materials.
Shaft bearings shall be outboard sealed ball bearings. Periphery seals shall be such that a complete seal is
accomplished at a differential of [_____] inches of water static pressure.
2.12.9 Ash Conveyor Pipe and Fittings
Abrasion resistant cast iron alloy free of blowholes and other defects and suitable for use in ash conveying
systems.
2.12.9.1 Conveyor Piping
Centrifugally cast, abrasion resistant cast iron alloy pipe with a Brinell hardness of not less than 280.
2.12.9.2 Elbows and Fittings
Cast iron alloy with a Brinell hardness of not less than 350 and shall have renewable wearbacks not less than
25 mm one inch thick.
2.12.9.3 Hangers and Supports
Provide adjustable roller supports and pipe hangers to properly support the pipe. System supplier shall design
support system and furnish supports.
2.12.9.4 Contractor's Option
At the Contractor's option, conveyor pipe handling only fly ash may be Schedule 80 black steel pipe in lieu of
the iron alloy pipe; however outlet fitting, elbows, tees and laterals shall be cast iron alloy with wearbacks
and the pipe for a distance of one meter 3 feet after the cast iron alloy fittings shall be cast iron alloy pipe.
Provide pipe with couplings or split flanges, bolts and gaskets, rated not less the 530 degrees C 1000 degrees
F.
2.12.9.5 Expansion Joints
Stainless steel bellows type with abrasion resistant liners of a Brinell hardness not less than 350 or slip tube
expansion joints fabricated of cast iron alloy, of Brinell hardness not less than 280, machined for smooth sliding
fit with its mating part to absorb system thermal movement and shock loads.
2.12.10 Vacuum Air Piping
Provide from the secondary separator to the tertiary bag filter and from the tertiary bag filter to the [steam
exhauster] [mechanical exhauster] not less than 10 gage, ASTM A 211, spiral welded, vacuum air piping with ASTM A 570/A 570M
, standard radius, mitered 10 gage elbows.
2.12.11 Compressed Air Piping and Accessories
Provide pressure reducing valves, safety valves, pressure gages, manual plug or ball valves, compressed air piping,
as specified under paragraph entitled "Piping" in this section and other items required for a complete, operable,
pneumatic system.
2.12.12 Primary Ash Receiver-Separator and Secondary Ash Separator
Provide on top of ash silo two stages of receiving and separating, with each stage a complete self-contained
unit with efficient dust and air separation and gravity dump bottom gates to open with interruption of vacuum
and discharge into a silo. Design system so that suction is positively shut off from the receiver during its
dumping period, so that no dust can be sucked out through the exhaust while the discharge of the receiver is
open or opening. Air from the primary receiver shall enter the external secondary separator which shall remove
approximately 85 percent of the dust not collected by the primary receiver. Combined efficiency of the primary
and external secondary separators shall be not less than 95 percent. Provide completely contained gate assemblies
in a dust-tight enclosure fitted with access doors large enough to remove entire gate assembly. Provide receivers
of hard, abrasion-resistant, cast alloy iron with a Brinell hardness of not less than 500 constructed as described
below:
2.12.12.1 Primary Receiver-Separator
Not less than [914] [1219] mm [36] [48] inches inside diameter with cast sections 19 mm 3/4 inch thick and 50
mm 2 inch thick impingement section. Cylinder, along with the discharge hopper shall be of segmental bolted
construction. Construct receiver to ensure dropping of the maximum quantity of solids from the transporting
air. Provide carbon steel outlet pipe and discharge gate. Receiver-separator shall have an internal baffle
assembly to prevent re-entrainment of ash.
2.12.12.2 Secondary Separator
Not less than [406] [508] [610] mm [16] [20] [24] inches inside diameter of not less than 8 mm 5/16 inch thick
one piece construction with at least 13 mm 1/2 inch thick inlet wear section. Design the receiver to minimize
the carry-over of fly ash into the [air washer] [tertiary bag filter]. Separator shall have an internal baffle
assembly to prevent re-entrainment of ash once it has fallen into the collection hopper of the separator.
2.12.12.3 Dust Tight Enclosure
Support primary and secondary receivers on not less than 6 mm 1/4 inch thick, dust tight, carbon steel support
boxes with hinged access doors or removable panels on each side for servicing the receiver swing gates. Provide
support box with airtight roller bearings, hinged, counterweighted swing gates with removable neoprene seals.
Gates may, as an option, be air cylinder operated gates in lieu of the counterweighted gates.
2.12.13 Mechanical Exhausters
NOTE: When environmental restraints, availability of steam or water or economics
preclude the use of steam exhausters, use a mechanical (electrical driven) exhauster
with a pulse jet bag filter to produce the required system air flow.
Provide two, V-belt drive, positive displacement blowers with electric motors and accessories with each capable
of producing a vacuum of at least 41 kPa 12 inches of mercury and with the air flow necessary for handling ashes
through the system. One blower (exhauster) shall be used as a prime mover and the other as a standby unit.
2.12.13.1 Isolation Gates
Each exhauster shall include a manual bolt-up type gate for isolation and crossover. Gates shall include limit
switches for status indication.
2.12.13.2 Accessories
Exhauster shall be complete with belt guard, air inlet silencer, air discharge snubber, support stand, expansion
joint on inlet and outlet, belt and shaft guards, high temperature safety switch and vacuum relief valve.
2.12.13.3 Electric Motor
Totally enclosed, fan cooled, [_____] volt, three phase, 60 Hz, as specified under paragraph entitled "Motors
and Drives" in this section.
2.12.13.4 Noise Level
Noise level shall not exceed 85 dBA sound pressure level at 1.50 meters 5 feet above the floor and 1.50 meters
5 feet from the blower in any direction.
2.12.14 Bag Filter
Provide a pulse jet self-cleaning bag filter assembly to provide a tertiary means of removing fine ash particles
from the conveying air system. Installation of this assembly shall be on the silo roof, downstream of the two-stage
cyclone type mechanical separator so as to permit a combined minimum separating efficiency of 99.5 percent (by
weight), with a guaranteed outlet emission less than 0.005 grains particulate per dry standard cubic foot of
exhaust air. The filter assembly shall include a main housing, bag assemblies, bag cleaning mechanism, discharge
gate and control panel. This equipment shall be integrated with cyclone type separators, vacuum breakers, vacuum
switches and conveying system controls as specified elsewhere. Bag filter shall be capable of operating at 25
percent above the system design vacuum. Filter housing shall be capable of withstanding a vacuum of 96 kPa 28.5
inches of mercury.
2.12.14.1 Cloth Area
Size filter on the basis of not greater than 25.40 L/s 5 acfm of air per square meter foot of cloth area. Calculate
acfm on the maximum system air flow.
2.12.14.2 Filter Construction
Welded construction housing or body of, ASTM A 36/A 36M plate with an upper clean gas plenum, bag compartment,
hopper bottom, internal access platform and support structure. Plate thickness shall be a minimum of 6 mm 1/4
inch with exception of the plenum tube sheet, which shall be a minimum of 13 mm 1/2 inch thick. Housing shall
be cylindrical, having a minimum diameter of [_____] meter feet [_____] mm inches.
a. Upper Gas Plenum: Dished head, with flanged inlet and discharge connections, tube sheet,
venturis and blow tubes. These appurtenances shall be welded airtight. Venturis shall be fabricated
from carbon steel having a minimum thickness of 16 gage. Minimum centerline spacing between
venturis shall be 191 mm 7 1/2 inches. A series of blow tubes shall be employed over the venturis.
Each tube shall extend through the wall of the dished housing and be manifolded externally.
Include support of external manifold.
b. Bag Compartment: Of sufficient height to allow internal access by maintenance personnel.
Base of this compartment shall include a metal platform supported by steel angle cross bracing.
Platform shall extend over the entire base area of the compartment. Sidewall of this compartment
shall include a hinged access door with locking handle. Door shall be gasketed and the opening
shall be a minimum of 762 mm high by 406 mm wide 30 inches high by 16 inches wide.
c. Hopper Bottom: Conical having a slope angle of not greater than 45 degrees with a flanged
outlet.
d. Access Platform: With [stairs] [ladder] and safety handrail for external mounting to the
filter housing. Mount platform at a height to allow convenient access through the hinged door
located on the bag compartment sidewall. Platform floor area shall be not less than 1.40 square
meter 15 square feet.
e. Provide filter housing with required columns and cross bracing to support structure from
the silo roof to discharge directly into the silo. This support shall be of sufficient height
to allow convenient installation of the filter discharge gate.
2.12.14.3 Discharge Gate
Air cylinder operated swing disc type. A rotary feeder type gate is not acceptable. When in the open position,
gate disc shall swing out of the path of material being discharged. Both gate disc and seal shall be replaceable.
A handhole shall be included on the gate housing for easy access to both disc and seat.
2.12.14.4 Bag Cleaning Mechanism
Provide venturis, blow tubes, manifold, solenoid air valves, diaphragm valves and differential pressure switch
conveniently located at the filter unit. Operation of these devices shall be on a sequential basis (adjustable
setting) to allow periodic surges of compressed air through the filter venturi sections. Compressed air requirement
for bag cleaning shall be not greater than 7.08 cubic meter per second at 690 kPa (gage) 15 scfm at 100 psig.
2.12.14.5 Bag Assemblies
Each filter bag assembly shall include the filtering media, wire retainer and stainless steel clamping device.
Filter bag shall slide over the retainer and both shall be clamped to the venturi by a stainless steel common
band clamp. Top portion of the retainer shall have inside dimension equal to the mating venturi to ensure a
tight fit.
a. Retainers: Cage type construction, fabricated from No. 1018 rounds or equal, using minimum
of 3 mm 1/8 inch diameter rounds on vertical strands and 5 mm 3/16 inch diameter rounds on horizontal
strands. Coat retainer with nickel and zinc after completion of fabrication.
b. Filter Bags: Not less than 474 g per square meter 14 ounces per square yard felted material.
Provide felted polyester or dacron bags when operating temperatures are below 135 degrees C
275 degrees F. Provide Nomex bags or bags of similar abrasion and temperature resistant qualities
when temperatures are above 135 degrees C 275 degrees F but not greater than 218 degrees C 425
degrees F. Bags shall have an exterior finish to aid in dust release.
2.12.14.6 Control Panel
Provide NEMA 4, wall mounted control panel to sequentially control the bag cleaning and dump operations of the
filter unit. Locate panel near the filter unit to permit easy field adjustment of sequence timers. Panel overall
dimensions shall be not less than 610 mm wide by 762 mm high by 200 mm deep 24 inches wide by 30 inches high
by 8 inches deep. As a minimum, the panel instrumentation shall include a dump cycle timer, pulse valve sequence
timer, two high differential pressure delay relays, alarm relay, time delay relay, manual/auto selector switch,
pulse valve "ON" indicating light, high differential indicating light, terminal blocks and internal wiring.
Welds and scratches of panel enclosure shall be free from blemishes. Paint panel exterior with manufacturer's
standard enamel. Interior of panel shall be white enamel. Shop inspect panel and test prior to shipment.
2.12.14.7 Vacuum Breakers
Provide two air cylinder operated vacuum breakers. One shall be a pop-up or single ported type for installation
in the air line between the secondary separator and tertiary bag filter. Second breaker shall be a three-ported
type for locations in the air line between the tertiary bag filter and the exhauster. Each breaker shall use
a disc type gate or equivalent to ensure full closure of the gate against its mating seat.
2.12.15 Steam Exhauster
NOTE: The steam exhauster system requires 0.32 kg 2500 pounds of steam per
second hour for a 150 mm 6 inch system (8 to 23 Mg9 to 25 tons per hour) and
0.44 kg 3500 pounds of steam per second hour for an 200 mm 8 inch system (13.6
to 31.75 Mg15 to 35 tons per hour) and approximately 1.89 L/s 30 gpm of water
to the air washer. A steam condenser, air washer and silencer should be used
when the steam exhauster is used and should not be used when a mechanical exhauster
is specified.
Provide a steam jet exhauster of cast iron construction with venturi throat of the high efficiency type for producing
the vacuum necessary for handling ashes through the system. Make inlet air connection on the steam jet exhauster
through a special spiral fitting so that the air enters the exhauster unit tangentially, avoiding direct impingement
on the nozzle. Provide a unit capable of producing a vacuum of at least 40.56 kPa 12 inches of mercury column
at shutoff and not requiring more than [0.32] [0.44] kg of steam per second at 690 kPa (gage) [2500] [3500] pounds
of steam per hour at 100 psig.
2.12.16 Steam Condenser, Air Washer and Silencer
NOTE: The steam exhauster system requires 0.32 kg 2500 pounds of steam per
second hour for a 150 mm 6 inch system (8 to 23 Mg9 to 25 tons per hour) and
0.44 kg 3500 pounds of steam per second hour for an 200 mm 8 inch system (13.6
to 31.75 Mg15 to 35 tons per hour) and approximately 1.89 L/s 30 gpm of water
to the air washer. A steam condenser, air washer and silencer should be used
when the steam exhauster is used and should not be used when a mechanical exhauster
is specified.
Provide a double stage cyclone type steam condenser, which also extracts the remaining solids from the steam-air
system. Construct steam condenser body of hard metal castings not less than 16 mm 5/8 inch thick suitable for
this special service except that the inlet connector shall be not less than 19 mm 3/4 inch thick. Castings shall
have a Brinell hardness of not less than 250. Other metal used in the condenser shall be at least 6 mm 1/4 inch
thick steel with the top not less than 13 mm 1/2 inch thick steel plate. Provide drain connection not less
than 76 mm 3 inches and water connection not less than 38 mm 1 1/2 inches. Provide silencer as required for
quiet operation.
2.12.17 Ash Storage Silo
NOTE: Use enclosures for silo roof and unloader in climates where protection
of equipment and personnel from the weather is desired.
[_____] meters feet in diameter with [_____] meters feet high walls with a live bottom and flyash storage capacity
of not less than [_____] Mg tons, based on ash bulk density of 640 kg per cubic meter 40 pounds per cubic foot
for volumetric sizing. Structural joints shall be dusttight and watertight. Provide columns, beams, bracing,
and other structural members as required for complete erection of silo and accessories. Live storage capacity
shall allow for 20 degree angle of repose from silo outlet. Height of silo storage shall not be more than twice
the diameter. Provide a minimum of one meter 3 feet of freeboard above the ash level. The design of the support
steel shall be approved by the ash system supplier. Design silo in accordance with the Uniform Building Code.
The design shall take into account seismic load, wind load, snow load, equipment loads and an ash bulk density
of 1120 kg per cubic meter 70 pounds per cubic foot. Ash silo support shall be free standing and shall be of
sufficient height to allow gravity discharge of ash through the rotary ash conditioner to a [truck] [railroad
car]. Provide access stair tower with intermediate platforms at 3.66 meters 12 foot intervals for access to
ash conditioner level, silo floor level and silo roof level. Platforms from adjacent structures with stair access
may be provided in lieu of the stair tower, but ladders with safety cages and access platforms must be additionally
provided. Provide ladder with stainless steel fall prevention device on inside of silo from manhole in top of
silo to bottom of silo. [Provide silo roof enclosure and unloader room enclosure each with single one by 2 meter
3 by 7 foot access door, [_____] by [_____] meter foot double door, two windows, ventilator, [heater], insulated
metal panel siding to match boiler plant walls and electrical lighting and convenience receptacles. Unloader
room enclosure shall have reinforced concrete floor.]
2.12.17.1 Construction
Construct silo of steel with refractory lining or of concrete staves with steel hoops and concrete roof. Roof
accessories shall include manhole, relief valve and vent filter. Bottom of silo shall be [conical, sloped a
minimum of 45 degrees.] [flat with a steel plate feeding hopper in bottom of silo to funnel ash into inlet of
rotary vane feeder.] Provide hopper with expansion joints and sufficient poke holes with cover or cap.
2.12.17.2 Concrete Stave Silo
Construct concrete stave silo of either lightweight solid or hollow precast concrete staves with post-tensioned
steel reinforcing hoops around the exterior. Mechanically measure and mix materials in concrete staves. Vibrate
and shape the staves under pressure and steam or air cure.
a. Wall Coating: Coat interior surface with a three-step process of a brush coat, scratch
coat, and finish trowel coat of a mixture of fine sand and portland cement in accordance with
the silo manufacturer's recommendations. Apply each coat successively to produce a smooth interior
surface. Work mixture into the formed horizontal and vertical grooves to permanently interlock
the concrete staves. Brush coat the exterior surface with a double application of waterproof
mixture. Mixture shall include a chemical agent for waterproofing and portland cement, sand,
and water. Work coating into joints and over the steel reinforcing hoops to form a weatherproof
protective coating.
b. Steel Reinforcing Hoops: Galvanized steel rods not less than 14 mm 9/16 inch in diameter
with not less than 16 mm 5/8 inch rolled threads. Join hoop ends together with nuts and heavy
malleable galvanized iron lugs or heavy duty galvanized steel lugs to a close tolerance for
a tight fit. Electrogalvanize rods, nuts, and lugs to ensure adequate protection against corrosion.
Rods shall be high quality, metallurgically sound steel with tensile strength not less than
448 MPa 65,000 psi, yield point not less than 276 MPa 40,000 psi, and a minimum elongation of
14 percent in 229 mm 9 inches. Reinforcing shall be sufficient to resist the maximum lateral
pressure and loads imposed by the ash pressure within the silo. Structurally connect hoop rods
that pass through silo outlets on inspection frames together.
c. Hollow Concrete Stave Silos: Construct silo of precast concrete staves with lateral air
spaces. Cast staves from a well proportioned mix of portland cement and an expanded clay light
weight aggregate. Minimum compressive strength of the concrete at 28 days shall be 34.50 MPa
5,000 psi. Hollow staves shall be 92 mm thick by 250 mm wide by 762 mm long 3 5/8 inches thick
by 10 inches wide by 30 inches long with five lateral air cores per stave, except that shorter
starter staves may be provided to permit the horizontal joints to be staggered.
d. Solid Concrete Stave Silos: Construct silo of solid lightweight precast concrete staves.
Solid staves shall be not less than 92 mm thick and 250 mm wide by 762 mm long 3 5/8 inches
thick and 10 inches wide by 30 inches long, except starter staves may be shorter. Solid staves
shall be constructed from a well proportioned mix of portland cement, washed sand and gravel
which is free from injurious organic impurities and contains less than 5 percent of deleterious
substances. Grade fine aggregate from coarse to fine. Compressive strength of solid concrete
staves at 28 days shall be 34.50 MPa 5,000 psi.
2.12.18 Pulse Jet Bag Filter Vent
NOTE: Consult the manufacturer of ash handling equipment for venting requirements.
Provide for the silo constructed of 10 gage steel plate, fitted with rain hood. Bag material shall be sateen
cotton capable of withstanding not less than 91 degrees C 195 degrees F, weighing 0.33 kg per square meter 9.75
ounces per square yard, having thread count of 4 by 2 per square mm 96 by 60 per square inch and permeability
of 76 to 102 L/s per square meter 15 to 20 cfm per square foot at 249 Pa one inch water column. Vent shall have
not less than [_____] square meter feet effective cloth filtering area, with each bag having a maximum effective
cloth filtering area of 0.56 square meter 6 square feet.
2.12.19 Rotary Ash Conditioner (Unloader)
Provide a complete dustless horizontal, floor mounted unloading device to discharge ashes from silo to a [truck]
[railroad car]. Unloader (ash conditioner) shall include a 762 mm 30 inch diameter revolving drum which rotates
about fixed spray nozzles, and shall be complete with conditioner and discharge compartments, scrapers, and other
accessories as required. Unloader drum shall be constructed of steel plate not less than 10 mm 3/8 inch thick
and shall be roller chain driven by a totally enclosed, fan cooled, [_____] volt, three phase, 60 Hz electric
motor not less than 3.75 mm 5 hp as specified under paragraph entitled "Motors and Drives" in this section.
The unloader shall discharge the conditioned ashes to a truck through a 6 mm 1/4 inch thick steel plate chute.
Unloader shall be designed to eliminate most dust in unloading ash from the ash silo. An unloader that utilizes
screws as a means of mixing is unacceptable. Dustless unloader shall add water to the ash, but not to the extent
that there is free or surplus water running or dripping from the ash after discharge. Discharge ash shall be
in a semi-fluid, loose, free flowing condition.
[2.12.20 Fluidizing System
NOTE: Delete fluidizing system when not necessary.
Provide a fluidizing system on the silo floor to ensure a constant and uniform feed of ash through the silo discharge
outlet. System shall consist of a series of diffuser modules, a conical diffuser hood, designed to support the
total weight of ash when the silo is full, and compressed air piping. Each diffuser module shall be mounted
on the silo floor using sloped concrete pads. System shall operate from the plant air system. Provide pressure
reducing valves, safety valves, and controls for a complete system.
]2.12.21 General Controls
Provide a centrally controlled operation, with auxiliary local operation, and a monitoring control system with
graphic display for the ash conveying system. Provide local control stop-start push buttons and indication stations
for chain drag conveyor, screw conveyors, bucket elevator, and rotary ash conditioner. Ash handling system manufacturer
shall provide measuring devices, status switches, solenoid valves, and auxiliary parts necessary to safely control
and operate the system. Provide related electrical work required to operate the ash handling system. [Ash handling
system manufacturer shall provide detailed control logic diagrams to the digital process control and data acquisition
system manufacturer specified under VAMS Section 23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT.]
2.12.21.1 Functions
Provide capability to perform any of the following functions from the operator interface console specified under
VAMS Section 23 09 53.00 20 CONTROLS NAD INSTRUMENTATION BOILER PLANT.
a. System Start
b. System Stop
c. Auto/Manual/Index Mode of Operation Selection
d. Selection of Bypass of any Boiler
e. Manual Index to any Intake
f. Selection of Ash Silo for Baghouse Ash
2.12.21.2 Status Indicators
Provide sensors or contact closures for status indication on the operator interface console specified under VAMS
Section 23 09 53.00 20 CONTROL SNAD INSTRUMENTATION BOILER PLANT[, or on the annunciator over the central control
panel] for the following:
a. Conveyor On
b. Unit On (one required for each unit)
c. Final Line Purge On/Complete
d. Baghouse Ash to Ash Silo
2.12.21.3 Alarms
Provide sensors such that the following items can be alarmed on the operator interface console specified under
VAMS Section 23 09 53.00 20 CONTROLS AND INSTRUMENTAITON BOILER PLANT[ or on the annunciator over the central
control panel]:
a. Blower Failure
b. Blower High Temperature
c. Bag Filter Failure
d. Bag Filter High Differential
e. Bag Filter Off
f. Plugged Hopper
g. Conveying Complete
h. Clinker Crusher Abnormal Shutdown (1 required for each boiler)
i. Low Conveying Air
j. High Conveying Vacuum
2.12.21.4 Vacuum Transmitter
To measure conveying system vacuum. Range shall be zero to 101 kPa 30 inches mercury with 4 to 20 mA dc linear
transmitter output. Display vacuum on the operator interface console specified under VAMS Section
23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT.
2.12.22 Controls Operation
2.12.22.1 Automatic
Normally operated in the automatic mode. Automatically sequence through automatic intakes except the clinker
crusher for each boiler after the system is started. When a unit is not in operation, selecting the "bypass
mode" shall cause intakes on that unit to be skipped. For Manual operation, "index" is used to select the desired
intake. As the conveying system shuts down automatically, the main conveyor line shall be purged for approximately
one minute to remove ash remaining in it.
2.12.22.2 Switching
Sequence system under the control of vacuum switches and timers. Maximum vacuum will be when system is conveying
material. When a hopper is empty, vacuum will drop and a "no load" vacuum switch shall cause the system to shift
to the next intake. Prevent premature sequencing due to momentary low vacuum with a timer. When a plugged hopper
occurs, vacuum will be between "no load" and normal value. Provide a timer to allow packed or arched material
to break loose before alarming the condition.
2.12.22.3 Valves
Provide solenoid air valves for each air operated device, timers, contactors, relays and devices and equipment
required for system control, measuring and operation. Identify each device with an engraved plastic identification
plate [in accordance with a system graphic display] provided by the ash handling system supplier.
2.12.22.4 Bottom Ash Hopper Local Control Stations
Provide a wall mounted, NEMA 250, control station at each bottom ash hopper with front access door, lock, circuit
breakers, selector switches, lights and push buttons.
a. Selector Switches:
(1) Crusher: three position switch, "Reverse (momentary)-Off-Forward"
(2) Rotary Valve Intake: two position switch "Open-Close"
(3) Vertical Lift Door: position switch "Open-Intermediate-Close"
b. Emergency "Stop" Pushbutton, For clinker crusher, with manual reset.
(1) "On-Manual"
(2) "Crusher Stalled"
2.13 AIR POLLUTION CONTROL EQUIPMENT
NOTE: Mechanical cyclone collectors should be used for soot blowing and as
a prefilter on baghouse fabric filters or electrostatic precipitators. The
fabric filter should be used where necessary to meet local, state or federal
regulations or statutes for particulate emissions, when sulfur emissions are
within regional limits through the burning of low sulfur "compliance coal."
When coal containing more than 2 percent sulfur is burned, an electrostatic
precipitator is generally more economical for control of particulates than the
fabric filters, when sulfur emissions will meet regional limitations. When
sulfur emissions are not within the regional limits, a scrubber with a prefilter
mechanical cyclone and possibly a baghouse filter may be required to meet the
emission limitations.
2.13.1 Mechanical Cyclone Collectors
As specified in Section 23 51 43.01 20 MECHANICAL CYCLONE DUST COLLECTOR OF FLUE GAS PARTICULATES.
2.13.2 Fabric Filter Baghouse
As specified in Section 23 51 43.03 20 FABRIC FILTER DUST COLLECTOR OF FLYASH PARTICULATES IN FLUE GAS.
2.13.3 Electrostatic Precipitator Filters
As specified in Section 23 51 43.02 20 ELECTROSTATIC DUST COLLECTOR OF FLUE GAS PARTICULATES.
2.13.4 Scrubbers
As specified in Section [23 51 43.00 20 DUST AND GAS COLLECTOR DRY SCRUBBER AND FABRIC FILTER TYPE.]
2.14 MISCELLANEOUS EQUIPMENT
2.14.1 Condensate Receiver
Provide a [horizontal] [vertical] type tank not less than [_____] meter feet [_____] mm inches in diameter by
[_____] meter feet [_____] mm inches [long] [high] overall with a storage capacity of not less than [_____] liters
gallons. Tank shall be constructed of welded steel plate not less than 10 mm 3/8 inch thick. Provide condensate
tank with a 610 mm 24 inch diameter manway, dual gage glasses with protective guards, saddles, and other connections
as indicated.
2.14.1.1 Coating
Surface blast interior of tank to bare metal and coat with a bake-on phenolic lining or corrosion resistant liner
consisting of a resin and hardener suitable for immersion in water at not less than 121 degrees C 250 degrees
F. Coat the exterior of the tank with one shop coat of manufacturer's standard primer rated for service of not
less than 121 degrees C 250 degrees F.
2.14.1.2 Accessories
Provide the condensate receiver with the following:
a. Connections for condensate pumped return, vent, water outlet, drain, sampling outlet, level
transmitter and controls.
b. [_____] mm inch vent.
c. Reflex type water gage glasses with shutoff valves and guards.
d. One, 125 mm 5 inch dial, thermometer, 10 to 149 degrees C 50 to 300 degree F range, with
lagging extension type wells, for steam and water space.
e. [_____] mm inch overflow trap.
f. One high water alarm switch with stainless steel float and trim. Circuit shall close as
liquid level rises. Locate switch to close circuit when water level rises to 25 mm one inch
below overflow level of receiver.
g. One low water alarm switch with stainless steel float and trim. Close circuit as liquid
level falls. Locate switch to close circuit when water level drops to 25 percent of the storage
capacity of the storage tank.
h. Switches on a single column with valved connections to tank. Provide unions in pipe on
each side of each float switch.
i. Pipe, fittings, controls, specialties, bolts, gaskets, drains, and valves, necessary for
a complete unit.
j. Provide automatic control system to control level in condensate tank by modulating discharge
from condensate pumps.
2.14.2 Deaerating Heater
Provide a deaerating feedwater heater with storage tank conforming to FS W-H-2904, except as modified below and
to ASME BPVC SEC VIII. Tank shall be ASME Code stamped. Provide stainless steel trays. No test model will
be required.
Model A - Pressurized operation.
Type I - Tray-type heating and deaerating element.
Class 3 - 10 minute water storage capacity (minimum).
Grade A - Guaranteed removal from water of dissolved oxygen in excess of 0.005 cubic centimeters
(cc) per liter, over a ten to one load swing.
2.14.2.1 Heater Capacity
Provide deaerating heater capable of heating and deaerating makeup water consisting of [_____] kilograms per
second (kg/sec) pounds per hour of softened makeup water from [_____] to [_____] degrees C F (outlet temperature).
2.14.2.2 Inlet Water Characteristics
Softened makeup water:
Ph: [_____]
Total hardness (as CaC03): [_____]
2.14.2.3 Storage Tank
Horizontal design with steel supports [drilled for bolting] of approved design. Provide storage tank with not
less than a 410 by 510 mm 16 by 20 inch minimum size manhole and cover and provide heater section with not less
than a 300 by 460 mm 12 by 18 inch minimum size tray access handhole and door.
2.14.2.4 Vent Condensing Arrangement
Provide the deaerating heater with a vent condenser which shall condense the vented steam when the heater is
operating at full capacity with the inlet water mixture at a temperature not exceeding 82 degrees C 180 degrees
F. Construct the vent condenser, when of the direct contact type, with stainless steel baffling.
2.14.2.5 Materials
Construct trays, tray supports, water distributors, and other parts coming in contact with undeaerated water
or air laden steam of 430 stainless steel.
2.14.2.6 Accessories
Provide the deaerating heater unit with the following accessories:
a. Pressure relief valve: Sized in accordance with FS W-H-2904.
b. Thermometers: Two, 125 mm 5 inch dial thermometers, 10 to 149 degrees C 50 to 300 degrees
F, with lagging extension type wells for the storage tank and the heater section. Provide a
thermometer similar to above but with range of minus [_____] degrees C F to plus [_____] degrees
C F for the makeup water connection.
c. Lifting attachments for the deaerator unit and the storage tank.
d. Water gage glasses: Reflex type with shutoff valve and guards.
e. Pressure gages: One 150 mm 6 inch dial compound pressure gage for the heater section with
range from [_____] kPa inches of mercury (vacuum) to [_____] kPa (gage) psig.
f. Float controllers:
(1) Inlet condensate controller
(2) Makeup water controller
(3) Overflow controller
g. Overflow control valve: With pneumatic controller arranged for local automatic operation.
h. Storage tank gage glass: Full height, shielded, for storage tank including shutoff valve
and drain cocks.
i. Makeup water inlet control valve: With pneumatic controller.
j. Switches: For low water level alarm in the storage tank, high water level alarm, condensate
pump shut-down in the storage tank, and low steam pressure alarm. Install switches on a single
column with connections valved and unions provided in pipe on each side of each float switch.
k. Special tools: One set for maintenance.
l. Condensate pump reset: With stainless steel float and trim to reset pump shutdown switch
on fall of liquid level in tank to [_____] mm inches below level of overflow level of storage
tank.
m. Furnish pipe, fittings, controls, specialties, bolts, gaskets, drains, and valves, necessary
for proper attachment of accessories and trimmings and install.
[n. Oil separator]
2.14.2.7 Connections
Provide necessary connections for condensate, steam, makeup water, removal of vented gases, vacuum breakers,
discharge of deaerated water, and as required for instruments and controls.
a. Provide heater connections as follows:
(1) [_____] mm inch steam inlet
(2) [_____] mm inch makeup water inlet
(3) [_____] mm inch condensate
(4) [_____] mm inch high pressure trap return
(5) [_____] relief valves sized as required
(6) [_____] mm inch vent
(7) [_____] mm inch for thermometer well
(8) [_____] mm inch for pressure gage
(9) Vacuum breakers: As required
(10) [_____] mm inch heater drain
(11) [_____] mm inch spare [capped] [flanged]
(12) [_____] mm inch spare [capped] [flanged]
(13) Handholes And manhole: With covers
b. Tank connections shall include:
(1) [_____] mm inch drain
(2) [_____] mm inch boiler feed recirculation ([_____] required)
(3) 25 mm one inch sampling
(4) 25 mm one inch chemical feed
(5) [_____] mm inch for sight glass ([_____] sets required)
(6) [_____] mm inch for high and low alarm switches
(7) [_____] mm inch thermometer well
(8) Vacuum breakers: As required
(9) [_____] mm inch spare (capped)
(10) [_____] mm inch spare (flanged)
(11) [_____] mm inch level transmitter and controller ([_____] sets required)
(12) Downcomer and equalizer: As required
(13) [_____] mm inch feedwater outlet
(14) [_____] mm inch overflow outlet with internal water seal
2.14.2.8 Level Control
Provide an automatic control system to control the water level in the storage tank, by modulating valves in the
makeup water lines. Output of the condensate pump shall be controlled by level in condensate storage tank.
a. Controllers: Provide external cage type air operated level controllers for both the condensate
and makeup water lines complete with 40 mm 1 1/2 inch screwed connections, external cage, and
controller. Cage body shall be Class 125 cast iron construction. Internal components including
displacer, torque tube, displacer rod, displacer rod driver and bearings shall be 316 stainless
steel. Displacer shall be 356 mm 14 inches long. Controller shall be direct acting with 20
to 103 kPa (gage) 3 to 15 psig range with proportional band adjustment. Locate controller to
maintain an operating level at 2/3 full point of storage tank. Provide level controller with
air pressure reducing valve, filter, gages and isolating valves for float cage. Provide unions
on each side of float cage.
b. Air operated regulating valves: Provide air operated control valves for both the condensate
and makeup water lines. Valves shall have Class 125 or Class 150 rating with iron or semi-steel
bodies and 316 stainless steel internals. Provide open on air failure condensate valve and
provide makeup water valve with an air lock mounted on valve diaphragm and piped to hold valve
in last position on air failure. Design valves for the following conditions:
Condensate Makeup Water
(1) Valve size [_____] [_____]
(2) Capacity (L/s) [_____] [_____]
(3) Maximum pressure drop
at above capacity
(kPa (gage)) [_____] [_____]
(4) Available pressure
kPa (gage) [_____] [_____]
(5) Minimum Cv at 100
percent open [_____] [_____]
Condensate Makeup Water
(1) Valve size [_____] [_____]
(2) Capacity (gpm) [_____] [_____]
(3) Maximum pressure drop
at above capacity (psig) [_____] [_____]
(4) Available pressure psig [_____] [_____]
(5) Minimum Cv at 100
percent open [_____] [_____]
2.14.2.9 Low Pressure Steam Control
Provide an automatic control system to control the steam to the deaerating feedwater heater. Maintain steam
pressure in the heater by modulating a pressure reducing valve in the steam supply line. Control shall be local
and remote from the control panel.
a. Controller: Adjustable proportional band, 0 to 103 kPa (gage) 0 to 15 psig brass bellows
for input signal, and 20 to 103 kPa (gage) 3 to 15 psig output air pressure range, pilot controller
complete with air set (valve, filter, drier and pressure regulator) mounted on control valve
yoke.
b. Pressure reducing station control valve: Provide a [_____] mm inch air operated pressure
reducing valve with proper internals to pass a flow of [_____] kg per second pounds per hour
of steam. Steam at the valve inlet shall be [_____] kPa (gage) psig saturated, and the outlet
shall be controlled at [_____] kPa (gage) psig. Minimum steam flow shall be approximately [_____]
kg per second pounds per hour. Minimum valve Cv shall be [_____] at 100 percent open. Valve
shall be Class 250 or Class 300 flanged, iron or semi-steel body with stainless steel internals
equal percentage flow characteristics and a full size port. Provide valve actuator including
travel indicator, hand jack, valve positioner, and air supply filter-reducer set. Valve shall
move to open position in case of failure.
2.14.2.10 Gage Glasses
Provide to cover the entire range of water level in the storage section. Gage glasses shall not be greater than
610 mm 24 inches center-to-center. Provide gage glasses complete with [chain operated] ball check shutoff and
drain cock valves and safety shield.
2.14.2.11 Alarms
Provide high and low water level alarms for storage tank as follows:
a. High water level alarm: Switch with stainless steel float and trim. Locate switch to close
circuit when water level rises to 25 mm one inch below overflow level of storage tank.
b. Low water level alarm: Switch with stainless steel float and trim. Locate switch to close
circuit when water level falls to [_____] meters feet [_____] mm inches above bottom of storage
tank.
c. Coordinate alarms with annunciator panel as indicated.
2.14.2.12 Multiport Back Pressure Relief Valve
Capable of relieving not less than [_____] kg per second pounds per hour of steam with not more than a [_____]
kPa (gage) psig pressure rise when set at [_____] kPa (gage) psig initial operating pressure and fully adjustable
by means of an external handwheel or chain operator for an initial set pressure of 0 to 172 kPa (gage) 0 to 25
psig. Locate on low pressure steam header manifold for the deaerating heater. Valve shall be multiport vapor
cushion type rated for operating temperatures up to but not greater than 149 degrees C 300 degrees F with Class
125 cast iron body, bronze trim and carbon steel springs.
2.14.2.13 Exhaust Head
FS A-A-50494, Type [I (cast iron)] [II (fabricated steel plate)] of [_____] mm inch size with [_____] mm inch
diameter drain, and a capacity of [_____] kg/sec pounds per hour of steam at [_____] kPa (gage) psig.
2.14.3 Boiler Feed Pumps
NOTE: Use this paragraph for centrifugal boiler feed pumps. Use Style 1, horizontal
split case pumps in all sizes. Pump service requirements shall include pump
capacity of a minimum of 125 percent of boiler requirements at maximum load.
Discharge head must be sufficient to deliver water to the boiler at a pressure
3 percent higher than the setting of the highest setting of the boiler safety
valves and up to 6 percent over the maximum operating pressure of the boiler
in accordance with ASME BPVC.
FS A-A-50562, Type II (boiler feed pump), Style 1 (horizontally split case), Class 2 (multi-stage) except as
modified below. Each pump shall be two stage with horizontal split casing, enclosed single suction opposed type
impellers, renewable casing and impeller wearing rings, stuffing box with quenching gland and flooded oil lubricated,
water cooled bearings.
2.14.3.1 Construction
Bronze fitted including bronze impeller and impeller wear rings, andASTM A 48/A 48M, Class 30, cast iron casing.
Provide casing with suction and discharge gages in tapped openings. Mount each pump and prime mover on a fabricated
steel bed plate having a drip collection chamber with tapped drain openings. Provide lifting attachments to
enable equipment to be set into its normal position and to enable split case pumps to be easily dismantled in
place.
2.14.3.2 Drives
Variable speed motors and turbines direct connected to respective pumps with a gear type, forged steel, flexible
coupling. Provide a shaft and coupling guard.
a. Electric motors: Variable speed, [open drip proof], [totally enclosed], [fan cooled], [_____]
volt, three phase, 60 Hz of not less than [_____] kW hp, as specified under paragraphs entitled
"Motors and Drives" and "Variable Speed Control For Motors" in this section.
b. Steam turbine: Single stage, rated at not less than [_____] kW hp, with inlet steam pressure
of [_____] kPa (gage) psig and [_____] degrees C F and normal exhaust back pressure of 34 kPa
(gage) 5 psig or a maximum back pressure of 103 kPa (gage) 15 psig. Water rate at full load
and normal steam conditions shall not exceed [_____] kg pounds per brake power hour. Provide
a stainless steel steam strainer, sentinel relief valve, sight oil level indicator and one hand
valve.
(1) Turbine construction: Turbine casing split on the horizontal centerline constructed of
ASTM A 48/A 48M, cast iron, with a design pressure rating of 1724 kPa (gage) at 232 degrees
C 250 psig at 450 degrees F at inlet, and 379 kPa (gage) at 232 degrees C 55 psig at 450 degrees
F at the outlet.
(2) Turbine bearings and shaft: Horizontal split, ring oiled, sleeve type, water cooled.
Shaft shall be stainless steel or chrome plated under the packing glands. Shaft seals shall
be segmented carbon rings with springs and stops.
(3) Speed governor: Variable speed oil relay, NEMA Class D, governor for speed control and
pneumatic operator to maintain an adjustable, preset pump discharge header pressure by variation
of turbine speed. Input to the operator shall be a 20 to 103 kPa (gage) 3 to 15 psig pneumatic
signal. Provide an electro-pneumatic transducer to accept the 4 to 20 mA signal from the control
system controller specified in VAMS Section 23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER
PLANT.
(4) Emergency overspeed governor: Completely independent of the speed governor and shall operate
a separate trip valve.
(5) Insulation: Turbine shall be insulated and lagged by the manufacturer as specified in
Section 23 07 00 MECHANICAL INSULATION.
2.14.3.3 Minimum Flow Protection for Boiler Feed Water Pumps
a. Automatic flow control valve: Provide with each pump an automatic bypass valve. Valve
shall automatically program the recirculation flow, the detection of low flow, the cycling of
control valve and pressure letdown for high pressure boiler feedwater return to the feedwater
heater. Bypass valve shall be cast steel with stainless steel internals, and shall have a rating
of not less than 2068 kpa (gage) at 204 degrees C 300 psig at 400 degrees F. Valve shall have
a line size body with a one inch recirculation connection. Provide pumps and turbine with all
trimmings which the manufacturer considers essential for proper operation of units.
b. Boiler feedwater automatic recirculation system: (Option to Automatic Valve). Provide
a boiler feedwater automatic recirculation system to protect the feedwater pumps at low flow
conditions. System shall be capable of recirculating the minimum flow recommended by the pump
manufacturer. System shall be an engineered system consisting of the various functional components
specified or shall be a self-contained and self-powered mechanical system. Components of the
engineered system shall include a flow transmitter with orifice in feedwater line, bypass flow
controller with bypass flow control valve, and a bypass pressure reducing orifice.
(1) System bypass flow controller: Include detection of low flow and modulation of a control
valve in a bypass line returning to a low pressure sink. Incorporate a pressure let-down feature
or device to reduce the pressure from the boiler feedwater pump discharge pressure to that of
the low pressure sink.
(2) System bypass control valve: Modulate to provide minimum flow recommended by the pump
manufacturer and to provide shutoff or recirculation flow when feedwater flow to boilers exceeds
the minimum flow required for pump protection.
2.14.3.4 Feedwater Stop and Check Valves
Provide a Class 300, flanged, cast steel feedwater stop gate valve and check valve on the feedwater outlet of
each pump. Provide piping from the valves to the economizer inlet, and from the economizer to the flanged connection
on the boiler drum. Provide connection on pipe at economizer outlet for remote recording thermometer.
2.14.4 Condensate Pumps
NOTE: Use this paragraph for centrifugal condensate pumps. Pump service requirements
shall include pump capacity at a minimum of 125 percent of full load boiler
requirements. Discharge into deaerator heater shall be modulated.
FS A-A-50562, Type I, Style [1 (horizontally split cast)] [2 (end suction)], Class 1 (single stage) unless modified
below.
2.14.4.1 Construction
Bronze impellers and impeller wear rings. [Cast iron] [ductile iron] pump casing designed for the specified
conditions. Bearings shall be oil lubricated. Equip casing with tapped openings for suction and discharge gages.
Provide gages in openings. Mount pump and driver on a fabricated steel bed plate having a drip collection chamber
with tapped drain openings. Provide lifting attachments for installation and maintenance.
2.14.4.2 Drives
Variable speed motors and turbines direct connected to the respective pumps with a gear type flexible coupling.
Provide shaft and coupling guards.
a. Electric motors: Variable speed, [open drip proof], [totally enclosed], [fan cooled], [_____]
volt, three phase, 60 Hz of not less than [_____] kW hp, as specified under paragraphs entitled
"Motors and Drives" and "Variable Speed Control For Motors" in this section.
b. Steam turbine: Single stage, rated at not less than [_____] with inlet steam pressure of
[_____] kPa (gage) psig and [_____] degrees C F, normal exhaust back pressure of 34 kPa (gage)
5 psig and a maximum back pressure of 103 kPa (gage) 15 psig. Water rate at full load and
normal steam conditions shall not exceed [_____] kg pounds per brake power hour. Provide a
stainless steel steam strainer, sentinel relief valve, sight oil level indicator and one hand
valve.
(1) Turbine construction: Turbine casing split on the horizontal or vertical centerline constructed
ofASTM A 48/A 48M cast iron, with a design pressure rating of 1724 kPa (gage) at 232 degrees
C 250 psig at 450 degrees F at inlet, and 379 kPa (gage) at 232 degrees C 55 psig at 450 degrees
F at the outlet.
(2) Turbine bearings shaft: Ring oiled, anti-friction type. The shaft shall be stainless
steel or chrome plated under the packing glands. Shaft seals shall be segmented carbon rings
with springs and stops.
(3) Speed governor: Variable speed governor for speed limiting and pneumatic operator to maintain
an adjustable preset level in [deaerator tank] [condensate receiver] by variation of turbine
speed. Input to the operator shall be a 20 to 103 kPa (gage) 3 to 15 psig pneumatic signal
and vary the turbine speed from minimum to full speed in a linear response. Maximum and minimum
speed shall be adjustable. Provide an electro-pneumatic transducer to accept the 4 to 20 mA
signal from the controller specified in VAMS Section 23 09 53.00 20 CONTROLS AND INSTRUMENTATION
BOILER PLANT.
(4) Emergency overspeed governor: Completely independent of the speed governor and shall operate
a separate trip valve.
(5) Insulation: Turbine shall insulated and lagged as specified in Section 23 07 00 THERMAL
INSULATION FOR MECHANICAL SYSTEMS.
2.14.5 Variable Speed Control for Motors
Remotely installed cabinet housed units with solid state rectification and inverter equipment to vary frequency
of electrical power to drive motors.
2.14.5.1 Housing
a. House controller in a [wall] [floor] mounted, NEMA 250 enclosure finished with manufacturers
standard painted finish. Provide control panel complete with fused disconnect switches, magnetic
[across the line] [part winding] starters with thermal overload protection, transformer, hand-off-automatic
selector switches, hand potentiometer for manual speed control, fuses and running lights.
b. Provide manual switch within control panel so that in the event of failure of a component,
the motor can be put across the line at full voltage to maintain air or pump pressure. Provide
a mechanical door interlock that will allow the panel to open only when the fused disconnect
is in the off position.
2.14.5.2 Variable Frequency Controllers
Variable frequency controllers shall use solid-state semiconductor power conversion equipment. Provide controllers
as integrated and assembled products. Provide controllers by the same manufacturer.
a. Each controller shall be rated for a supply of [_____] volts, three phase, 60 Hz. The output
shall be [_____] volts, three phase with frequency variable between zero and 60 Hz. Controllers
shall be rated to operate the motors continuously at their rated horsepower and frequency.
Speed regulation shall be three percent or better without tachometer feedback. The electrical
supply system has an available short circuit rating of [_____] amperes symmetrical.
b. Each controller shall be capable of driving the motor continuously at a lower speed no greater
than 20 percent of full rated motor speed with stable operation and without overheating the
motor under rated ambient conditions. Provide estimate of minimum speed at which motor can
be operated continuously without overheating or problems of instability due to overhauling of
the load.
c. Provide controller fault protection so that a single or three phase short circuit at the
controller terminals or inverter commutation failure will not result in damage to power circuit
components. Provide overload protection so that motor and controller are protected against
operating overloads.
d. Provide adjustable time delay undervoltage protection so that motors will continue to operate
during momentary voltage fluctuation or loss of voltage. Time adjustment shall be zero to 5
seconds. Provide for orderly shutdown on undervoltage conditions exceeding the time delay interval.
e. Provide adjustable timed linear acceleration and deceleration.
f. Provide volts/hertz control to prevent motor overheating throughout the speed range.
g. Provide door interlocks to prevent opening of enclosure doors unless power is disconnected.
h. Controllers shall be self protecting and shall provide orderly shutdown for, but not limited
to, the following conditions:
(1) Loss of input power
(2) Undervoltage
(3) Sustained gradual overload
(4) Fault or large instantaneous overload
(5) Overtemperature
(6) Failure of ventilating system
(7) Overvoltage
(8) Control circuit failure
i. Provide contacts for remote annunciation of shutdown or abnormal condition.
j. Electrical bypass: Provide each controller with manual isolation and bypass switching.
The switch shall be manually operated with controller deenergized. Switch shall be two position
with provisions for locking the switch in either position.
(1) Normal position: Bypass shall be open and the controller shall be connected to the supply
circuit and the load.
(2) Bypass position: Bypass shall be closed and controller shall be electronically isolated
from the supply and the load. Isolating contacts shall be located so that it is possible to
verify by visual inspection that the contacts are open and the controller is electrically isolated.
In the bypass position the motor shall be operated at constant speed and controlled from the
air circuit breaker. Provide auxiliary contacts that close in the bypass position. The auxiliary
contacts shall be used to activate the damper control to provide fan load control in the bypass
position.
2.14.5.3 Controller Environmental Protection
a. Ventilation: Design controllers enclosed and ventilated for installation in a moderately
dusty area. Provide forced filtered ventilation including fans, filters, controls and accessories
required for operation. Enclosures shall be operated under positive pressure at all times.
Provide filtered ventilating openings and gasketed doors to prevent infiltration of dust.
b. Heating: Provide electric heaters to prevent condensation in the enclosure and to prevent
low in going air temperatures that exceed the equipment rating. Provide a low temperature alarm
to sound when enclosure temperature falls below required minimum temperature. Provide contacts
for remote annunciation of alarm condition.
2.14.5.4 Method of Control
Supply each controller from an electrically operated air circuit breaker or motor starter. Controller ventilation
and heating shall be from another circuit.
a. Start signal: Closes the electrically operated air circuit breaker or motor starter to
energize the controller. Controller shall accelerate fan to operating speed. Fan speed shall
be controlled from the load control signal.
b. Stop signal: Opens the electrically operated air circuit breaker or motor starter to de-energize
the controller. Upon deenergization, the controller control system shall revert to the stop
condition.
c. Boiler feedwater pump speed control system: Matches pump discharge to system demand and
maintains a system header pressure controlled to the set point values. Provide Manual/Automatic
control stations for master pressure and for each boiler feed pump. Provide indicators for
feedwater header pressure and individual boiler feedwater pump flow. See VAMS Section
23 09 53.00 20 CONTROLS AND INSTRUMENTATION BOILER PLANT.
2.14.6 Valve Actuators
[Electrically] [or] [pneumatically] operated designed so that valve may be manually operated by removing the
drive pins. Actuators shall be operated by push button control. Locate one push button at a position adjacent
to the valve. Locate a second push button within the boiler control room. Provide a valve position indicator
utilizing indicating lights. A green light shall indicate the valve is fully open and an amber light shall indicate
the valve is fully closed. Both lights on shall indicate when the valve is partially open. [Provide torque
limit controls to protect the valve during opening and closing for electrically operated valves.] Actuator electric
motor shall be totally enclosed, [_____] volts, [_____] phase, 60 Hz as specified under paragraph entitled "Motors
and Drives" in this section. Provide NEMA 4 control enclosures.
2.14.7 Sump Pumps
FS A-A-50555 with automatic float switch and disconnect switch in NEMA 6 enclosure.
2.14.8 Water Softening System
NOTE: Size the system for 125 percent of the maximum expected steam load to
100 percent of plant capacity. Include losses from blowdown. Size with one
tower regenerating. Frequency of regeneration should be between 12 and 24 hours
at peak loading.
Ion exchange resin type, conforming to WQA S-100 except as modified below. [Manual] [Push button automatic]
[Fully automatic] in operation with operating controls housed in a NEMA 12 enclosure having a total capacity
between regenerations of not less than [_____] liters gallons of water of [_____] grams grains hardness when
operated at a sustained softening rate of [_____] L/s gpm. Maximum effluent water temperature shall be [_____]
degrees C F.
2.14.8.1 Softener Equipment
Including but not limited to the following:
a. Water hardness monitor: Provide a water hardness monitor with an alarm point at 1.0 ppm
to assure compliance for boilers rated above 3150 grams/sec 25,000 lbs./hr.
b. Total solids monitor/controller: Provide a continuous monitor and controller when required
to control the concentration of dissolved solids and treatment chemicals in the water for boilers
rated above 3150 grams/sec 25,000 lbs./hr.
c. Water meter: Provide a [_____] mm inch cold water meter on each softener unit.
d. Ion exchange resin: High capacity, polystyrene base, sulfonated synthetic type except that
the exchange capacity shall be not less than 68.70 kg per cubic meter 30 kilograins per cubic
foot at a salt dosage of 240 kg per cubic meter 15 pounds per cubic foot.
e. Tank sizing: Minimum acceptable bed depth of 762 mm 30 inches; maximum acceptable bed depth
of 1829 mm 72 inches. Base reactor tank sizes on allowing a freeboard above the resin bed of
not less than 75 percent of the resin bed depth, and flow rate between 1.11 and 7.13 L/s per
cubic meter 0.5 and 3.2 gpm per cubic foot of resin.
2.14.8.2 Brine Storage System
Provide a complete brine storage system including fiberglass storage tank, sight level gage, bulk salt delivery
tube, internal distribution system, level control system, tank vent with dust collection system, top and side
manholes, access ladder, and other required appurtenances.
a. Storage tank: Filament wound fiberglass with flat bottom and domed top as recommended by
the manufacturer for brine storage. The tank shall be [_____] meters feet [_____] mm inches
in diameter by [_____] meters feet [_____] mm inches wall height with a nominal capacity of
[_____] liters gallons and a dry salt storage capacity of [_____] Mg tons. Design the water
distribution system, internal piping distributors, and brine collection system so that system
shall be capable of dissolving [_____] kg pounds of rock salt per second minute to produce [_____]
L/s gpm of brine. System shall be able to dissolve [_____] Mg tons of salt before cleanout.
b. Accessories: Provide the following accessories:
(1) Steel holddown lugs securely bonded to the tank in adequate number to properly anchor tank
to concrete base
(2) Side bottom flanged drain not less than 100 mm 4 inches in diameter
(3) Side and top manholes not less than 559 mm 22 inches in diameter
(4) Flanged top connections for delivery pipe and vent
(5) Ladder for access to top manhole
(6) Water inlet connection
(7) Brine outlet connection
(8) Level control system
(9) Sight level gage
c. Pneumatic delivery pipe: Not less than 100 mm 4 inches in diameter.
d. Dust collection vent system and safety relief valve: Provide storage tank with dust collection
vent system and safety relief valve.
e. Access ladder: Of steel construction to be bolted to tank by means of FRP mounting lugs
complete with safety cage. Platform shall connect ladder to tank for safe access to manhole.
f. Tank internals: Construct tank internals including water distribution piping and brine
collectors of FRP or polyvinyl chloride (PVC).
g. Tank nozzles: ASME B16.5, Class 150, reinforced FRP or PVC flanges.
h. Level control system: Electrode holder and electrodes mounted in a standpipe exterior to
the tank. Position electrodes so that a solenoid operated water makeup valve will be opened
or closed to maintain the liquid level to within plus or minus 25 mm one inch of the set level.
Provide tank with a high water alarm. Electrodes shall be easily removable for cleaning and
constructed of materials, that will allow continual immersion in brine.
2.14.9 Chemical Feed Systems
Provide systems complete with storage tank, supporting framework, hinged cover, mixer, strainers, level indicators,
proportioning pumps, relief valves and interconnecting piping for a complete chemical feed packaged unit.
2.14.9.1 Storage Tank
190 liters50 gallon capacity constructed of FRP. Provide removable, hinged cover.
2.14.9.2 Exterior Gage Glass
Protected, full height of the tank complete with gage cocks.
2.14.9.3 Low Level Alarm
Provide tank with a low level switch to sound alarm and shut down pumps should level drop to preset minimum.
2.14.9.4 Dissolving Baskets
Construct baskets of a corrosion resistant material suitable for continuous immersion in a [_____] solution.
NOTE: The chemical feed solution to be used shall be inserted here.
2.14.9.5 Tank Strainer
In suction line to pump.
2.14.9.6 Supporting Steelwork
Provide supporting steelwork to adequately support tank, mixer, and the number of proportioning pumps specified.
2.14.9.7 Agitator
Provide an agitator with mounting bracket to mount to storage tank. Agitator shaft and propeller shall be of
stainless steel.
2.14.9.8 Proportioning Pumps
Provide [two] [three] [_____] proportioning pumps of the [simplex] [duplex] type. Each pump shall have a minimum
capacity of [_____] L/s gph at a [_____] kPa (gage) psig discharge pressure. Capacity shall be adjustable from
zero to 100 percent by a convenient screw adjustment of stroke length. Provide pump with integral check valves.
Electric motors shall be [totally enclosed], [fan cooled], [_____] volts, [_____] phase, 60 Hz as specified under
paragraph entitled "Motors and Drives" in this section.
2.14.9.9 Safety Relief Valve
Provide for each pump to discharge back into the tank in event of excessive line pressure.
2.14.10 Welded Blowdown Tank
Provide in accordance with the Recommended Rules for the Design and Arrangement of Boiler Blowoff Equipment supplemental
to the National Board Inspection Code latest edition published by the National Board of Boiler and Pressure Vessel
Inspectors, Columbus, Ohio.
a. Construction: Construct equipment and accessories in accordance with the requirements of
the ASME BPVC SEC VIII for a working pressure of at least the maximum allowable working pressure
of the boiler but in no case shall the plate thickness be less than 10 mm 3/8 inch. Provide
corrosion allowance of [2.55 mm] [0.1 inch] [_____]. Tank dimensions shall be [_____] meters
feet [_____] mm inches O.D. by [_____] meters feet [_____] mm inches long over the heads (overall).
Provide tank with wear plate not less than 10 mm 3/8 inch thick and [279 by 381 mm11 by 15 inch
] [457 by 508 mm18 by 20 inch] manhole.
NOTE: The volume of the blowdown tank shall be calculated to be twice the volume
of water removed from one boiler when the normal water level is reduced not
less than 100 mm 4 inches.
b. Tank connections: Provide the following connections:
(1) Blowdown inlet for bottom blowdown [20] [25] mm [3/4] [1] inch
(2) Tangential blowdown inlet [_____] mm inch
(3) Steam vent, flanged [_____] mm inch
(4) Discharge water outlet, flanged [_____] mm inch with internal water seal and 20 mm 3/4
inch siphon breaker
(5) Drain 50 mm 2 inch
(6) Thermometer connection 20 mm 3/4 inch
(7) Pressure gage connection 6 mm 1/4 inch
(8) Cold water inlet [_____] mm inch with temperature regulating valve and backflow preventer
(9) Two gage glass connections 15 mm 1/2 inch
c. Angle supports and coating: Provide the tank with steel angle support legs extending [_____]
meter feet below the bottom of the tank. Coat the tank with one coat of manufacturer's standard
high temperature primer.
2.14.10.1 Accessories
a. Gage glass: 300 mm 12 inch reflex type with shutoff valves and guard.
b. Thermometer: Bi-metal dial type with separable socket, 125 mm 5 inch dial, 10 to 149 degrees
C 50 to 300 degrees F range.
c. Pressure gage: Zero to 172 kPa (gage) Zero to 25 psig range.
d. Internal baffles and pipes: As detailed.
2.14.10.2 Controls
Provide a self operating regulator to control the flow of cooling water to the tank. Regulator shall include
a 20 mm 3/4 inch screwed bronze body with stainless steel trim, reverse acting actuator for cooling, capillary
tubing and a union connection bulb with a stainless steel well. Control setting shall be 60 degrees C 140 degrees
F with a minimum Cv of [_____].
2.14.11 Continuous Boiler Blowdown System
Provide a complete automatic continuous boiler blowdown system, in accordance with NBBPVI NB-27, which shall
include a controller/programmer unit and flow assembly for each boiler, plus a continuous blowoff heat exchanger,
flash tank and boiler water sample cooler.
2.14.11.1 Automatic Blowdown Controller
Intermittent type boiler blowdown system rated for not less than 1724 kPa (gage) 250 psig steam pressure.
a. Flow assembly: Include a 25 mm one inch ball valve with 316 stainless steel ball and stem
and stainless steel electrode assembly.
b. Controller/programmer: Include a conductivity meter with zero to 6000 micromhos range,
valve open/closed indicators and manual/auto control switch. Cycle interval and sample duration
shall both be adjustable over a wide range. Mount units at the operating floor near the boiler
front.
c. Accessories and connections:
(1) Continuous blowdown connection: At each boiler, provide a gate valve and extend piping
to header at flash tank.
(2) Header connections: Provide with a tee with valved sampling connection. Provide a 20
mm 3/4 inch, three globe valve bypass around each flow assembly.
(3) Common header: Provide from valved outlet connections on flow assembly units, to connection
on flash tank.
2.14.11.2 Flash Tank
ASME code stamped and constructed in accordance with the ASME BPVC SEC VIII designed for [_____] kPa (gage) psig
. Tank shall be [_____] mm inches in diameter by [_____] mm inches long including heads.
a. Provide tank with blowdown inlet, steam outlet, gage glass, float operated outlet valve,
relief valve, and inspection openings. Tank shall have steel angle legs with plate feet for
bolting to floor and legs shall be of sufficient length so that bottom of lower head of tank
will be not less than 457 mm 18 inches above floor.
b. Automatic control system: Control level in the flash tank, by modulating a valve in the
water outlet line.
(1) Level controller: External cage type air operated level controller, complete with 40 mm
1 1/2 inch screwed connection, 350 mm 14 inch stainless steel float and Class 125 cast iron
body. Controller shall be direct acting with 20 to 103 kPa (gage) 3 to 15 psig range with proportional
band. Locate controller to maintain an operating level at center line of storage tank. Provide
level controller with air pressure reducing valve, filter, gages and isolating valves for float
cage. Provide unions on each side of float cage.
(2) Outlet water valve: [_____] air operated control valve with a capacity to pass [_____]
L/s gpm at a pressure drop of [_____] kPa (gage) psig. Cv shall not be less than [_____] at
100 percent open. Valve shall be Class [_____], flanged, iron or semi-steel body with stainless
steel internals. Valve shall have equal percentage flow characteristics with a full size port.
Provide an air lock mounted on valve diaphragm and piped to hold valve in last position on air
failure.
2.14.11.3 Sample Cooler
Water cooled shell and tube type with valves and accessories required to safely withdraw a water sample from
the boiler drum. Provide drain under sampling valve terminating with a 20 mm 3/4 inch splash proof funnel, 229
mm 9 inches below outlet of valve.
2.14.11.4 Heat Exchanger
Provide an ASME code stamp continuous blowoff heat exchanger designed and constructed in accordance with the
ASME BPVC SEC VIII, to transfer heat from the continuous blowoff water leaving the existing continuous blowoff
flash tank to the treated makeup water entering the feedwater heater. Heat exchanger shall be a bare tube, helical
coiled bundle, installed in a one piece casing with removable front plate. Bundle shall be removable. Tube
diameter shall not be less than 20 mm 3/4 inch. Tubes shall be ASTM B 111/B 111M copper alloy, with cast iron
shell. Design tube side for not less than [_____] kpa (gage) psig pressure at [_____] degrees C F. Design shell
side for not less than [_____] kpa (gage) psig pressure at [_____] degrees C F.
2.15 PIPING
Piping work shall include the provision, of piping systems, including valving and specialty items, for the steam
plant and related external auxiliary equipment.
a. Piping materials, design, and fabrication shall be in accordance with ASME B31.1 except
as modified otherwise below or indicated otherwise.
b. Compute expansion of pipe with operating temperatures above minus 19 degrees C zero degrees
F in lieu of 21 degrees C 70 degrees F specified in ASME B31.1.
c. Requirements of ASME B31.1 apply to the building steam heating and steam distribution piping
designed for 103 kpa (gage) 15 psig or lower and hot water heating systems 207 kpa (gage) 30
psig or lower.
2.15.1 Materials
Suitable for the maximum pressure at the maximum temperature at which the equipment must operate.
2.15.1.1 Pipe Materials
a. Steel pipe
(1) Steam pipe, boiler feedwater pipe, relief pipe and steam tracer pipe: Black, ASTM A 53/A 53M
or ASTM A 106/A 106M seamless steel pipe, Grade A or B. Wall thickness not less than Schedule
40. Steam tracer pipe, with steam up to 103 kPa (gage) 15 psig, may be ASTM B 88M ASTM B 88
, type K copper tubing.
(2) Condensate pipe and boiler blowdown pipe: Black, welded or seamless ASTM A 53/A 53M or
ASTM A 106/A 106M, steel pipe, Grade A or B. Wall thickness not less than extra strong (XS or
Schedule 80).
(3) Chemical feed pipe and coal pile-runoff water sump pump discharge piping: ASTM A 312/A 312M
austenitic stainless steel.
(4) Fuel oil pipe: ASTM A 53/A 53M or ASTM A 106/A 106M, seamless black steel pipe, Grade
A or B.
(5) Treated water, hot water heating, high temperature water, drains (other than sanitary),
and overflow pipe: black, welded or seamless steel up to a maximum pressure of 1724 kPa (gage)
250 psig or ASTM A 53/A 53M or ASTM A 106/A 106M, Grade A or B.
(6) Gas pipe and compressed air pipe: Welded or seamless pipe up to a maximum pressure of
1724 kpa (gage) 250 psig or ASTM A 53/A 53M or ASTM A 106/A 106M, Grade A or B.
b. Copper tubing
(1) Instrument air pipe: ASTM B 88M ASTM B 88 hard copper tubing, Type K or L; except in a
corrosive atmosphere or outside pipe shall be copper tubing, Type K or L, with ASTM D 1047 PVC
jacketing.
(2) Steam tracer pipe: Contractor may at the Contractor's option provide ASTM B 88M ASTM B 88
, Type K, copper tubing for steam up 103 kPa (gage) 15 psig.
(3) Potable water, sanitary drains and storm drains: As specified in Section 22 00 00 PLUMBING
SYSTEMS, unless otherwise specified. Chlorinated polyvinyl chloride (CPVC) and other plastic
tubing and fittings shall not be used in the steam heating plant.
2.15.1.2 Fittings
a. Fittings for steel pipe:
(1) Sizes 6 to 50 mm 1/8 to 2 inches: ASME B16.3 malleable iron, screwed end fittings, for
working pressures not greater than 2068 kpa (gage) 300 psig at temperatures not greater than
232 degrees C 450 degrees F or ASME B16.11 forged steel.
(2) Sizes 6 to 50 mm 1/8 to 2 inches: ASME B16.11 steel, socket welded end fittings.
(3) Sizes 6 to 65 mm 1/8 to 2 1/2 inches: ASME B16.9 steel, butt welding fittings.
(4) Sizes 65 to 600 mm 2 1/2 to 24 inches: ASME B16.5 forged steel, flanged fittings.
b. Welded outlets and welding saddles: Make branch connections of 45 and 90 degrees either
with ASME B16.9 forged steel welded outlet fittings or welding saddles. Welding outlets and
saddles shall not be smaller than two pipe sizes less than the main pipe sizes.
c. Fittings for copper tubing: ASME B16.18 cast bronze solder joint or ASME B16.22 wrought
copper solder joint. For instrument air, fittings may be ASME B16.26 compression joint type.
d. Unions:
(1) Unions for steel pipe: ASME B16.11, ASME B16.39 threaded. Unions for zinc coated pipe
shall be zinc coated.
(2) Unions for copper tubing: ASME B16.22. For instrument air, unions may be compression
joint type.
2.15.1.3 Flanges
ASME B16.5, forged steel, welding type. Remove the raised faces on flanges when used with flanges having a flat
face. Except as specified otherwise, pressure and temperature limitations shall be as specified in ASME B16.5
for the proper class and service, and the type face specified.
2.15.1.4 Valves
a. Valves for maximum working pressure of 1034 kpa (gage) 150 psig saturated steam or 1550
kPa (gage) 225 psig W.O.G. (Water, Oil, Gas) at 93 degrees C 200 degrees F (non-shock service).
(For working pressures not exceeding 862 kPa (gage) 125 psig saturated steam or 1379 kpa (gage)
200 psig water at 93 degrees C 200 degrees F non shock service, Class 125 may be used in lieu
of Class 150 or Class 250).
(1) Valve sizes 50 mm 2 inches and smaller:
(a) Non throttling valves: Gate valves, bronze, wedge disc, rising stem, Class 150, MSS SP-80
or ball valves, bronze, double stem seals, stainless steel ball and shaft, tight shutoff.
(b) Globe valves and angle valves: Bronze, Class 150, MSS SP-80.
(c) Check valves: Bronze, Type [IV, swing check] [III, lift check], Class 150, MSS SP-80.
(2) Valve sizes 65 mm 2 1/2 inches and larger.
(a) Gate valves: Flanged, cast iron, Class 250,
MSS SP-70 or steel, Class 150, ASME B16.34. Valves shall have wedge disc, outside screw and
yoke (OS&Y), rising stem; valves 200 mm 8 inches and larger shall have globe valved bypass.
(b) Globe valves and angle valves: Flanged, cast iron, Class 250, MSS SP-85 or steel, Class
150, ASME B16.34.
(c) Check valves: Flanged, cast iron, Class 250 or steel, Class 150, Type [_____], [lift]
[swing] check, style [_____], MIL-V-18436.
b. Valves for maximum working pressure of 1724 kPa (gage) 250 psig steam at a maximum temperature
of 232 degrees C 450 degrees F or 3447 kPa (gage) 500 psig W.O.G. at 93 degrees C 200 degrees
F (non-shock).
(1) Valve sizes 65 mm 2 1/2 inches and larger.
(a) Gate valves: Flanged or butt welded, cast iron, Class 250, MSS SP-70 (maximum size 300
mm 12 inches) or steel, Class 300, ASME B16.34. Valves shall have wedge disc, OS&Y, rising
stem; each valve 200 mm 8 inches and larger shall have globe valved bypass.
(b) Globe valves and angle valves: Flanged or butt welded, cast iron, Class 250, MSS SP-85
or steel, Class 300, ASME B16.34.
(c) Check valves: Flanged or butt welded, iron body, Class 250 or steel, Class 300, Type [_____]
[lift] [swing] check, style [_____], MIL-V-18436.
c. Valves for maximum working pressure of 2068 kPa (gage) 300 psig steam at a maximum temperature
of 454 degrees C 850 degrees F or a maximum W.O.G. pressure of 4653 kPa (gage) 675 psig at 149
degrees C 300 degrees F (non shock).
(1) Valve sizes 65 mm 2 1/2 inches and larger:
(a) Gate valves, Globe Valves, and Angle Valves: Flanged or butt welded, ASME B16.34, steel,
Class 300, rising stem, OS&Y. Gate valves 200 mm 8 inches and larger shall have globe valved
bypass.
(b) Check valves: Flanged or butt welded, steel, Class 300, Type [_____], [lift] [swing] check,
style [_____], MIL-V-18436.
d. Ball valves: ASME B16.5 and API Std 607 double stem seal type for bubble tight shutoff.
Seats and seals shall be TFE material. Ball and shaft shall be stainless steel. Provide mechanical
stops to prevent cycling valve in wrong direction and self-aligning stem seal.
e. Valve accessories: ASME B16.34 valve operating mechanisms including chain wheels, gear
operators, floor stands, electric motors, air motors and cylinder-type actuating devices. Provide
the accessories as follows and as indicated.
(1) Provide power operators with remote position indicators on the following valves: soot
blowers, [_____], [_____].
(2) Provide floor stands and valve extensions on platforms and floors for the following valves:
deaerator drain valves, [_____].
(3) Provide motorized actuators or chain wheels with chain and guides on valves with handwheel
centerline higher than 2 meters 7 feet above the floor or platform except where specified otherwise.
Chains shall extend from the valve to within one meter 3 feet above the floor. Provide impact
chain wheels on steam headers and other locations where the valve has a tendency to stick.
When a valve is motorized, provide hand operation for emergency.
(4) Provide gear operators on ball valves larger than 80 mm 3 inches and on gate valves 200
mm 8 inches and larger.
f. Steam pressure regulating valves: FS A-A-50558, minimum of Class [125] [150] [250] [300],
except as specified otherwise. [Cast iron], [cast steel] valve body with valve seats and disc
of replaceable heat treated stainless steel. Valves shall be single seated, shall seat tight
under dead end conditions, and shall go to the closed position in the event of pressure failure
of the operating medium. Valves shall be spring loaded diaphragm operated type, except valves
exposed to ambient temperature of less than 2 degrees C 35 degrees F or exposed to the weather
shall be piston operated type. Capacity of valves shall be not less than that indicated. Pilot
valves shall have strainer at inlet from external feeder piping.
(1) Spring loaded diaphragm operated valves: Fabricate main spring of stainless steel, and
it shall not be in the path of steam flow through the valve. Control valves by pilot valve
through external feeder piping.
(2) Piston operated valves: Control valves by integral pilot valve through external feeder
piping.
g. Safety relief valves: MIL-V-18436, Style D or E, with Class [150] [300] inlet flange, with
test lever, designed for the intended service.
2.15.1.5 Bolts and Nuts
a. Bolts: ASTM A 193/A 193M, Grade B8. Lengths of bolts shall be such that not less than
two full threads will extend beyond the nut with bolts tightened to required tensions and washers
seated.
b. Nuts: ASTM A 194/A 194M, Grade 8.
2.15.1.6 Gaskets
ASME B31.1 and as specified below, except provide spiral wound metal covered non-asbestos gaskets in lieu of
compressed sheet non-asbestos. Gaskets shall be as thin as the finish of surfaces will permit. Do not use paper,
vegetable fiber, rubber, or rubber inserted gaskets for temperatures greater than 121 degrees C 250 degrees F
. Provide metal or metal jacketed non-asbestos gaskets with small male and female and small tongue-and-groove
flanges and flanged fittings; they may be used with steel flanges with lapped, large male and female, large tongue-and-groove,
and raised facings. Provide full face gaskets with flat-faced flanges. Raised face cast iron flanges, lapped
steel flanges, and raised faced steel flanges shall have ring gaskets with an outside diameter extending to the
inside of the bolt holes. Widths of gaskets for small male and female and for tongue-and-groove joints shall
be equal to the widths of the male face and tongue. Gaskets shall have an inside diameter equal to or larger
than the port opening. Dimensions for nonmetallic gaskets shall be in accordance with ASME B16.21. Materials
for flanged gaskets shall be as listed below for service specified:
a. Steam, boiler blowdown, exhaust steam: Spiral wound metal composition or copper
b. Boiler feed water: Metal jacketed non-asbestos, copper or monel
c. Hot water, above 38 degrees C 100 degrees F: Spiral wound metal non-asbestos
d. Cold water: Red rubber or neoprene rubber
e. Heavy fuel oil (No. 6): Spiral wound metal non-asbestos, soft steel, or monel
f. Diesel fuel (No. 2): ASME B16.21 metallic
g. Compressed air: Spiral wound metal non-asbestos
2.15.1.7 Expansion Joints
a. Slip tube expansion joints: MIL-E-17814, Type IV, single or double slip tube as indicated,
designed for [1034] [2068] kPa (gage) [150] [300] psig saturated steam working pressure. Expansion
joints shall be of the type which permits the injection of semi plastic type packing while the
joint is in service under full line pressure. Slip tube shall be of chromium plated, wrought
steel construction, guided by internal and external guides integral with joint body. Fit slip
tube ends with forged steel pipe flanges or bevel for welding into pipe line where indicated.
Deliver joints complete with packing and ready for installation.
b. Flexible ball expansion joint: Capable of 360 degrees rotation plus 15 degrees angular
flex movement and shall be installed in strict accordance with recommendations of the manufacturer.
Ball joints shall have steel bodies and polished steel balls. Provide end connections to suit
class of piping herein before specified. Seals shall be of pressure molded composition designed
for the working pressure. Design joints for [1034] [2068] kPa (gage) [150] [300] psig saturated
steam working pressure. Cold set joints as necessary to compensate for temperature at time
of installation. Do not use ball joints on superheated steam or on joints subject to frequent
flexure.
c. Bellows expansion joints: MIL-DTL-17813 flexible guided type with stainless steel expansion
element, internal sleeves and external covers. Joints shall be designed for a working pressure
of [_____] kPa (gage) psig and a temperature of [_____] degrees C F.
2.15.1.8 Pipe Hangers and Supports
MSS SP-58 and MSS SP-69, Type [______] or Type [_____] of the adjustable type, except as specified or indicated
otherwise. Suspended steam and condensate piping shall have pipe hangers Type [_____] with insulation protection
saddles Type [_____]. Provide insulated piping, except steam and condensate piping, with insulation protection
shields Type 40. Provide bronze or copper plated collars on uninsulated copper piping. Support rods shall
be steel. Rods, hangers and supports shall be zinc plated, except for uninsulated copper piping which shall
be copper plated; cast iron rollers, bases and saddles may be painted with two coats of heat resisting aluminum
paint in lieu of zinc plating. Axles for cast iron rollers shall be stainless steel. Size hanger rods with
a 150 percent safety factor for a seismic design.
2.15.1.9 Instrumentation
a. Pressure and vacuum gages: Conform to applicable requirements of ASME B40.100.
b. Indicating thermometers: MIL-T-19646 dial type. Thermometer shall include a separable
immersion well.
2.15.1.10 Miscellaneous Pipeline Components
a. Cold and hot water meters: FS A-A-59224 for maximum flow of [_____] L/s at 38 degrees C
gpm at 100 degrees F and reduced flow of up to [_____] L/s at 121 degrees C gpm at 250 degrees
F.
b. Air traps: Float controlled valves arranged to close properly when water enters the traps.
Air traps shall conform to requirements for float operated steam traps (non-thermostatic), FS A-A-60001
, except that the valve mechanism shall be inverted so as to be closed, not opened, by rising
water.
c. Steam traps: FS A-A-60001. Inverted bucket high pressure steam traps designed for use
at [_____] kPa (gage) psig at [_____] degrees C F. Low pressure steam traps shall be float
and thermostatic type for pressures up to 103 kPa (gage) 15 psig. Provide traps with separate
strainers unless specified otherwise.
d. Strainers: FS WW-S-2739 for Class [125] [250] with blow off outlet. Construct strainers
for Class 300 of cast carbon steel in accordance with ASME B16.5 for minimum of 2068 kPa (gage)
300 psig saturated steam pressure. Provide blow off outlet with pipe nipple and gate valve.
e. Steam exhaust heads: FS A-A-50494 for atmospheric discharge of exhaust steam.
2.15.1.11 Backflow Preventers
Reduced pressure principle type conforming to the applicable requirements of [AWWA C510 and AWWA C511.] [Section
22 00 00 PLUMBING SYSTEMS.]
2.15.1.12 Insulation
Materials and application shall be as specified in Section 23 07 00 THERMAL INSULATION FOR MECHANICAL SYSTEMS.
2.15.1.13 Pipe Sleeves
a. Floor Slabs, Roof Slabs, and Outside Walls Above and Below Grade: Galvanized steel pipe
having an inside diameter at least 15 mm 1/2 inch larger than the o.d. diameter of the pipe
passing through it. Provide sufficient sleeve length to extend completely through floors, roofs,
and walls, so that sleeve ends are flush with finished surfaces except that ends of sleeves
for floor slabs shall extend 13 mm 1/2 inch above finished floor surface. Sleeves located in
waterproofed construction shall include flange and clamping ring.
b. Partitions: Galvanized sheet steel, 26 gage or heavier, of sufficient length to completely
extend through partition thickness with sleeve ends flush with partition finished surface.
2.15.1.14 Piping Identification
Piping Identification shall conform to MIL-STD-101 and shall be placed in clearly visible locations; except that
piping in the boiler room shall be painted the primary color of the color code. Labels and tapes conforming
to ASME A13.1 shall be used in lieu of band painting or stenciling. Labels shall be outdoor grade acrylic plastic.
Markings on labels shall indicate the direction of flow, flowing media, and media design pressure and temperature.
Spacing of identification marking shall not exceed 3 meters 10 feet. Provide two copies of the complete color
and stencil codes used. Frame codes under glass and install where directed.
2.16 FIRE PROTECTION SYSTEM
Provide the fuel oil room with a wet sprinkler system as specified in Section 21 13 13.00 20 WET PIPE SPRINKLER
SYSTEM, FIRE PROTECTION.
2.17 MARKING
Identify equipment, valves, switches, motor controllers, and controls or indicating elements, by printed, stamped
or manufactured identification plates or tags of rigid plastic or non-ferrous material. Lettering for identification
plates or tags shall be not less than 5 mm 3/16 inch high. Nomenclature and identification symbols used on the
identification plates or tags shall correspond to those used in the maintenance manuals, operating instructions,
and schematic diagrams. Identification plates or tags shall be rigidly affixed to the equipment or devices without
impairing functions or, when this is not possible, shall be attached using a non-ferrous wire or chain. In addition
to the identification plate or tag, each major component of equipment shall have a nameplate listing the manufacturer's
name, model number, and when applicable, electrical rating and other information required by pertinent standards
or codes.
2.18 TOOLS AND TESTING EQUIPMENT
Provide special tools and wrenches required for the installation, maintenance, and operation of the equipment.
Testing equipment to be provided shall include necessary equipment to perform routine tests:
a. On lubricating oil for acidity (pH-potentiometer), viscosity (saybolt test), and dirt (gravimetric).
b. On softened water for hardness (soap test or colorimetric test), and boiler blowdown water
for pH (colorimetric) and conductivity (potentiometer).
c. For water (distillation) and sediment (gravimetric) in fuel oil.
2.19 WELDING MATERIALS
Welding materials shall comply with Section 2, ASME BPVC SEC II-C. Welding equipment, electrodes, welding wire,
and fluxes shall be capable of producing satisfactory welds when used by a qualified welder or welding operator
using qualified welding procedures.
2.20 MOTORS AND DRIVES
A.C. electric motors shall meet the requirements of NEMA MG 1. Motors shall be designed for continuous operation
at rated load under usual service conditions as defined by NEMA. Unless specifically noted otherwise, motors
less than 3/8 kW 1/2 hp shall be 115 volt, 60 Hz, single phase, capacitor-start, or permanent split capacitor,
with Class B insulation for 40 degrees C 104 degrees F ambient. Unless specifically noted otherwise, motors
3/8 kW 1/2 hp and larger shall be 460 volt, 60 Hz, three phase, Design B, squirrel cage induction with a minimum
insulation of Class F for 40 degrees C 104 degrees F ambient. Size motors to meet power requirements of the
driven unit at design conditions, including drive and coupling losses which are incurred, without loading the
motor beyond its nameplate horsepower rating. Minimum service factor for open drip-proof motors shall be 1.15
and for totally enclosed, fan cooled motors 1.0. Motor shall be quiet operating. Bearings shall be heavy duty,
grease lubricated, anti-friction, single shielded, regreasable type and shall have approved lubricating fittings
extended to an easily accessible location for field servicing. Provide sole plates for motors installed on concrete
pads. Motors shall have copper windings.
2.21 SOURCE QUALITY CONTROL
2.21.1 Instrument Air Compressors
Factory test air compressor package at full load for not less than 2 hours. Check capacity, smoothness of operation,
alternation of units, and proper operation of the air unloaders during the test.
2.21.2 Variable Speed Motor Controller Factory Test
Burn-in tests shall be conducted for at least 50 hours at rated conditions. Replace each component that fails
during the burn-in test, and the test shall be run on the entire assembly for the complete 50 hours. Burn-in
test shall not be complete until the entire assembly has operated for 50 hours without failure.
PART 3 EXECUTION
3.1 INSTALLATION
Install materials and equipment as indicated and in accordance with manufacturer's recommendations.
3.1.1 Boiler
3.1.1.1 Installing Tubes In Headers
Tubes may be rolled into the headers provided the holes used for rolling will not be blocked for access in the
future by any item of equipment or piping, provided under this contract. Otherwise, weld tubes into the headers
by use of stubs or socket welds. Stub end tubes may be welded into headers in shop and tubes welded to same
in field.
3.1.1.2 Installing Tubes In Drums
Before installing tubes, polish tube ends and tube seats in the drums to bright metal using a No. 60 grit cloth
grinding band driven on a pneumatic or electric polishing motor. Do not polish these tubes until ready for immediate
installation. Install the tubes and hold in place with proper width, hard maple wood spacers and by lapping
the tubes in the tube sheet. Lap tubes only enough to hold them in place for rolling. Check tube stock on
each end of the tube before rolling. Furnish 10 mm 3/8 inch stock on each tube end with no deviation. When,
after the tubes are rolled in place, there remains more than 10 mm 3/8 inch stock due to extra length of tube,
excess shall be milled off to 10 mm 3/8 inch using a milling wheel driven by a pneumatic or electric motor.
At no time shall there be less than 10 mm 3/8 inch stock between end of tube and nearest surface of header.
Tubes shall then be rolled with a bell roll of the proper size and tension. Tubes shall not be rolled to excess.
Drive bell roll by a pneumatic or electric motor using a proper size mandrel pin. At no time will a manual
operation of tube rolling be permitted. Lubricant for the expanding operation shall be a water soluble compound.
3.1.1.3 Inspecting Tubes
After tubes are rolled in place, provide, under manufacturer's supervision, one person in steam drum and one
in mud drum. The person in the steam drum shall drop a ping pong ball through every tube to be sure that no
foreign matter or misalignment obstructs the tube. After boiler tubes have been tested, follow the same procedure
on the water wall tubes. Remove each tube that is not in alignment after being installed and install a new tube
in its place.
3.1.1.4 Installing Firebrick
Lay up in air-setting mortar. Dip each brick in mortar, rub, shove into its final place, and then tap with a
wooden mallet until it touches the adjacent bricks. Mortar thick enough to lay with a trowel will not be permitted.
Maximum mortar joint thickness shall not exceed 3 mm 1/8 inch and average joint thickness shall not exceed 1.60
mm 1/16 inch.
3.1.1.5 Installing Plastic Refractory
Install in accordance with the manufacturer's recommendations and by workmen skilled in its application.
3.1.1.6 Installing Casing Insulation
Before application of the insulations, clean exterior surfaces of the boiler not covered by brick work by commercial
blast and finish with one coat of FS TT-P-28 aluminum heat-resisting paint. Apply paint directly to cleaned
metal surfaces to a minimum dry film thickness of 0.0254 mm one mil.
3.1.2 Equipment Installation
Install equipment in strict accordance with this specification, and with manufacturer's installation instructions.
Grout equipment mounted on concrete foundations before installing piping. Install piping in such a manner as
not to place strain on equipment. Flanged joints shall not be bolted to final torque settings until the flanges
are aligned, gasketed and mated properly. Expansion bends shall be adequately extended before installation.
Grade, anchor, guide and support piping, without low pockets.
3.1.2.1 Equipment Foundations
Provide foundations of sufficient size and weight, and proper design to preclude shifting of equipment under
operating conditions, or under abnormal conditions which could be imposed upon the equipment. Equipment vibration
shall be limited within acceptable limits, and shall be isolated. Foundations shall be adequate for soil conditions
of the site and shall meet requirements of the equipment manufacturer. Trowel exposed foundation surfaces smooth
except surfaces which are to receive grout, which shall be properly roughened.
3.1.2.2 Induced Draft Fan
Provide each driver and reduction gear with a 38 mm 1 1/2 inch thick steel base plate. Shim base plate level,
using steel shim stock which is at least as large as the equipment foot and is slotted for installation around
studs or bolts. Anchor and grout into place prior to setting driver. An approved millwright shall align and
shim the drive unit. Millwright shall drill and ream foot and base plate and install taper pins with nut on
top for pullout removal. One front foot and diagonally opposite rear foot shall be pinned to base plate. Bolt
equipment in place in a manner approved by the manufacturer. Level and grout fan and bearing pedestal sole plates
in place.
3.1.2.3 Stack
Stack shall be leveled and plumb during installation. Erected stack shall be no more than 25 mm one inch out
of plumb per 15 meters 50 feet in height. Remove roughness, marks, and lifting lugs from stack. Grind surfaces
smooth and flush with surrounding surfaces.
3.1.2.4 Fuel Oil Tanks
NOTE: At the text below, choose one of the following fuel oil tanks found below.
[a. Horizontal Fuel Oil Tanks (Below Ground). Provide concrete ballast slabs for tanks and
concrete protective ground level slabs for FRP tanks. Ballast slabs shall be full length and
width of tanks and protective slabs shall extend 610 mm 2 feet beyond the tanks. Concrete work
shall be as specified in Section 03 30 00 CAST-IN-PLACE CONCRETE.
(1) Install backfill fiberglass reinforced tanks as recommended by the manufacturer; backfill
adjacent to the tanks shall be pea gravel unless otherwise recommended by the manufacturer.
Backfill for steel tanks shall be sand.
(2) Set steel tanks on a bed of sand not less than 152 mm 6 inches deep over the concrete slab
and strap in place with stainless steel hold-down straps with stainless steel turnbuckles.
Set FRP tanks on a bed of pea gravel not less than 305 mm 12 inches thick and pre-shape for
the tank contours for FRP tanks. Fabricate straps for FRP tanks from FRP resins reinforced
with stainless steel to prevent breaking of straps and floating of empty tanks.
(3) Slope tank toward sump not less than 25 mm in each 1.50 meters one inch in each 5 feet.]
[b. Horizontal Fuel Oil Tanks (Above Ground). Continuously support steel tank saddles along
the full length of the base and level and grout to ensure full bearing.]
[c. Vertical Fuel Oil Tank. Provide [sand, crushed stone or fine gravel cushion] [concrete
base].]
NOTE: Choose for a base material either sand/ crushed stone/fine gravel or
a concrete base.
(1) Sand, Crushed Stone or Fine Gravel Cushion: Area beneath tank shall be covered with a
fuel resistant plastic membrane with a thickness of not less than 0.50 mm 20 mils. Carefully
fuse or cement plastic membrane seams. Lay plastic over a thoroughly compacted select subgrade
free from rocks that could puncture the plastic. Over the plastic provide a bed of sand, crushed
stone or fine gravel not less than 152 mm 6 inches thick. Stabilize the bed with an approved
material and shape to the tank bottom. Slope bed down to the center sump approximately 152
mm 6 inches for each 3 meters 10 feet of tank radius. When in place, tank shell shall be plumb.
(2) Concrete base shall be as indicated and in accordance with Section 03 30 00 CAST-IN-PLACE
CONCRETE.
(3) Mastic Seal: Place the mastic seal between the tank and the concrete ring to the cross
section indicated. Compact the mastic thoroughly. Immediately before placing the mastic, coat
the tank surfaces to be in contact with the concrete ring with a coat of MIL-C-18480 bituminous
material.
3.1.3 Piping
Unless specified otherwise, erection, welding, brazing, testing and inspection of piping shall be in accordance
with ASME B31.1 and Section 40 17 26.00 20 WELDING PRESSURE PIPING. Piping shall follow the general arrangement
shown. Cut piping accurately to measurements established for the work. Work piping into place without springing
or forcing, except where cold-springing is specified. Piping and equipment within buildings shall be entirely
out of the way of lighting fixtures and doors, windows, and other openings. Locate overhead piping in buildings
in the most inconspicuous positions. Do not bury or conceal piping until piping has been inspected, tested,
and approved. Where pipe passes through building structure, pipe joints shall not be concealed, but shall be
located where they may be readily inspected and building structure shall not be weakened. Avoid interference
with other piping, conduit, or equipment. Except where specifically shown otherwise, vertical piping shall run
plumb and straight and parallel to walls. Piping connected to equipment shall be installed to provide flexibility
for vibration. Support and anchor piping so that weight of the piping is not putting equipment under a load.
3.1.3.1 Fittings
Provide long radius elbows on welded piping to reduce pressure drops due to bends in the piping runs. Do not
miter pipe to form elbows or notch straight runs to form full sized tees, or similar construction. Make branch
connections with welding tees or factory made forged welding branch outlets and nozzles having integral reinforcements
conforming to
ASME B31.1.
3.1.3.2 Grading of Pipe Lines
Unless indicated otherwise, install horizontal lines of steam and return piping to grade down in the direction
of flow with a pitch of not less than 25 mm in 9 meters one inch in 30 feet, except in loop mains and main headers
where flow may be either direction. Pitch air lines to the source of supply, and make provisions for draining
off condensate. Install water lines to drain to a shutoff valve.
3.1.3.3 Anchoring, Guiding, and Supporting Piping
NOTE: Pipe hangers and supports shall be spaced and designed to support steam
piping filled with water for hydrostatic tests.
Anchor and support piping in a manner such that expansion and contraction will take place in the direction desired,
prevent vibration by use of vibration dampeners, and prevent undue strains on boilers and equipment served.
Fabricate hangers used for the support of piping of 50 mm 2 inch nominal pipe size and larger to permit adequate
adjustment after erection while still supporting the load. Provide wall brackets where pipes are adjacent to
walls or other vertical surfaces which may be used for supports. Provide supports to carry the weight of the
lines and maintain proper alignment. Provide inserts and sleeves for the supports in concrete where necessary
and place in new construction before pouring concrete. Provide insulated piping with a pipe covering protection
saddle at each support. Provide pipe guides and anchors of approved type at points where necessary to keep pipes
in accurate alignment, to direct expansion movement, and to prevent buckling and swaying and undue strain.
Provide pipe guides for alignment of pipe connecting the free unanchored ends of each expansion joint. Support
pipe rollers in concrete conduits and trenches by extra strong steel pipe with ends inserted in slots provided
in concrete walls. Set pipe supports for rollers at correct elevations either by metal shims or by cutting away
of concrete and after placing pipe lines in alignment, grout ends of pipe supports and fix in place. Space pipe
supports to provide adequate support for pipes. Pipe shall not have pockets formed in the span due to sagging
of the pipe between supports, caused by the weight of the pipe, medium in the pipe, insulation, valves, and fittings.
Maximum spacing for pipe supports for steel pipe shall be in accordance with ASME B31.1; maximum spacing for
supports for copper tubing shall be in accordance with PHCC-1983 National Standard Plumbing Code.
3.1.3.4 Copper Tubing
Copper tubing shall have solder joints with solder suitable for the pressure-temperature ratings of the piping
system. Tubing 20 mm 3/4 inch and smaller for instrument air may be compression joint in lieu of soldered joint.
Tin-antimony (95/5) solder is suitable for saturated steam up to 103 kPa (gage) 15 psig but tin lead (50/50)
solder is not acceptable for steam service. Flux shall be non corrosive. Wipe excess solder from the joints.
3.1.3.5 Sleeves
Provide pipe sleeves where pipes and tubing pass through masonry and concrete walls, floors, and partitions.
Space between pipe, tubing, or insulation and the sleeve shall be not less than 6 mm 1/4 inch. Hold sleeves
securely in proper position and location before and during construction. Sleeves shall be of sufficient length
to pass through entire thickness of walls, partitions, and slabs. Sleeves in floor slabs shall extend 13 mm
1/2 inch above the finished floor. Firmly pack space between pipe or tubing and the sleeve with oakum and caulk
on both ends of the sleeve with elastic cement.
3.1.3.6 Flashing for Buildings
Where pipes pass through building roofs and outside walls, provide proper flashing and counter flashing and make
tight and waterproof.
3.1.3.7 Outlets for Future Connections
Locate as directed capped or plugged outlets for connections to future equipment, when not located exactly by
the project drawings.
3.1.3.8 Screwed Joints in Piping
Provide teflon tape or suitable pipe joint compound applied to male threads only for making up screwed joints.
Piping shall be free from fins and burrs. Ream or file out pipe ends to size of bore, and remove chips.
3.1.3.9 Welded Joints
Weld joints in piping by the metal-arc or gas welding processes in accordance with ASME B31.1 and as specified
in Section 40 17 26.00 20 WELDING PRESSURE PIPING. Number or mark each weld to identify the work done by each
welder on welds on which stress relieving or radiographic inspection is required.
a. Contracting Officer reserves the right to require the Contractor to provide re-examination
and re-certification of welders.
b. Radiographic testing of circumferential butt welded joints of pipe with operating temperature
of 177 degrees C 350 degrees F and above shall be required on ten percent of the joints, the
location of which will be determined by the Contracting Officer; when more than ten percent
of the radiographically tested joints show unacceptable defects radiographically test joints
of this type piping.
c. Equipment and Protection: Items of equipment for welding shall be so designed and manufactured,
and shall be in such condition as to enable qualified operators to follow procedures and to
attain the results specified. Protect welders and gas cutters from the light of the arc and
flame by approved goggles, shields, helmets, and gloves. Replace cover glasses in helmets and
shields when they become sufficiently marred to impair the operator's vision. Take care to
avoid risk of explosion and fire when welding and gas cutting near explosive or flammable materials.
Ventilate welding and gas cutting operations in accordance with paragraph 29 CFR 1910-SUBPART Q
(f) of Title 29 of the Code of Federal Regulations).
d. Surface Conditions: Do not weld when atmospheric temperature is less than minus 18 degrees
C zero degrees F, when surfaces are wet, when rain or snow is falling or moisture is condensing
on surfaces to be welded, nor during periods of high wind, unless welder and work are protected
properly. At temperatures between zero and mins 18 degrees C 32 and zero degrees F heat with
a torch the surface for an area within 80 mm 3 inches of the joint to be welded to a temperature
warm to the hand before welding. Free surfaces to be welded from loose scale, slag, rust, paint,
oil, and other foreign material. Joint surfaces shall be smooth, uniform and free from fins,
tears, and other defects which might affect proper welding. Remove slag from flame-cut edges
to be welded by grinding, but temper color need not be removed. Thoroughly clean each layer
of weld metal by wire brushing prior to inspection or deposition of additional weld metal.
3.1.3.10 Cleaning of Piping
Before installing pipe, thoroughly clean it of sand, mill scale and other foreign material. After erection but
before final connections are made to apparatus thoroughly clean interior of piping. Flush with water piping
except air and fuel lines, in addition, blow out steam lines with intermittent high pressure steam blows to promote
shedding of internal scale; blow compressed air and fuel oil lines clean with 552 to 690 kPa (gage) 80 to 100
psig air dried to a 2 degrees C 35 degree F dew point at 552 kPa (gage) 80 psig. Sterilize potable water piping
by means of liquid chlorine or hypochlorite in accordance with AWWA C651 before placing water system in service.
Take care during fabrication and installation, to keep piping, valves, fittings and specialties free of loose
welding metal chips of metal or slag, welding rods and other foreign matter. Blowing or flushing shall in no
case be channeled through equipment, pump, control valve, regulating valve, instrument gage or specialty in the
system. Provide temporary screens, strainers, connections, spool pieces and bypasses consisting of piping or
hoses, pumps and other required equipment temporarily installed for the purpose of cleaning and flushing piping.
Drain flushing water and test water to the sanitary sewer system.
3.1.3.11 Reduction in Pipe Size
Provide reducing fittings for changes in pipe size; the use of bushings will not be permitted. In horizontal
steam lines, reducing fittings shall be the eccentric type to maintain the bottom of the lines in the same plane.
In horizontal water mains, reducers shall be set to maintain top of lines in the same plane.
3.1.3.12 Expansion Control
Provide bends, loops, and offsets wherever practical to relieve overstressed piping systems due to thermal expansion
and to provide adequate flexibility. Cold spring piping system as indicated but not more than an amount greater
than 50 percent of the total linear expansion.
3.1.3.13 Connection to Equipment
Provide unions or flanges where necessary to permit easy disconnection of piping and apparatus. Provide unions
and gate valves at each connection to threaded end control valves, strainers and equipment.
3.1.3.14 Valve Installation
Install valves in positions accessible for operation and repair. Install stems in a vertical position with handwheels
or operators on top or in a horizontal position. Do not install handwheels on stop valves below the valve.
When the centerline of any valve is more than 2 meters 7 feet above the floor or platform, provide the valve
with a chain-operated handwheel. When the valve is motorized, provide hand operation for emergency use.
a. Gate Valves: Arrange back outlet gate valves for turbine exhaust for hand operation and
provide with a floor stand.
b. Globe Valves: Pressure shall be below the disc. Install globe valves with stems horizontal
on steam and exhaust lines, when better drainage is required or desired.
c. Steam Pressure-Reducing Valves: Provide the steam line entering each pressure-reducing
valve with a strainer. Provide each pressure-reducing valve unit with two shutoff valves and
with a globe or angle bypass valve and bypass pipe. A bypass around a reducing valve shall
be of reduced size to restrict its capacity to approximately that of the reducing valve. Provide
each pressure-reducing valve unit with indicating steam gages to show the reduced pressure and
the upstream pressure and an adequately sized safety valve on the low pressure side.
d. Valve Tags and Charts: Permanently tag each valve with a black and white engraved laminated
plastic tag showing valve number, valve function and piping system and whether another valve
must be opened or closed in conjunction with this valve. Provide a typed chart which will show
the required valve tagging plus the location of each valve; frame valve charts under glass and
install as directed.
3.1.3.15 Traps and Connections
Traps shall be of the type and capacity for the service required, and shall be properly supported and connected.
Except for thermostatic traps in pipe coils, radiators, and convectors, install traps with a dirt pocket and
strainer between it and the piping or apparatus it drains. Whenever it is necessary to maintain in continuous
service apparatus or piping which is to be drained, provide a three valve bypass so that the trap may be removed
and repaired and condensate drained through the throttled bypass valve. Provide a check valve on the discharge
side of the trap whenever the trap is installed for lift or operating against a back pressure, or it discharges
into a common return line. Provide test connections on the discharge side of the high and medium pressure traps
when they are specifically required. Test connection shall include a 15 mm 1/2 inch globe valve with open blow.
3.1.3.16 Pressure Gage Installation
Pressure gages shall have a shutoff valve or petcock installed between the gage and the line, and gage on steam
lines shall have a siphon installed ahead of the gage.
3.1.3.17 Thermometer and Sensing Element Installation
Provide thermometers and thermal sensing elements of control valves, with a separable socket. Install separable
sockets in pipe lines in such a manner to sense flowing fluid temperature and minimize obstruction to flow.
3.1.3.18 Strainer Locations
Provide strainers with meshes suitable for the services upstream of each control valve and where dirt might interfere
with proper operation of valve parts, orifices, or moving parts of equipment.
3.1.3.19 Dissimilar Piping Materials
Provide dielectric unions or flanges between ferrous and nonferrous piping, equipment, and fittings, except that
bronze valves and fittings may be provided without dielectric couplings for ferrous-to-ferrous or nonferrous-to-nonferrous
connections. Dielectric fittings shall utilize a nonmetallic filler which will prevent current flow from exceeding
one percent of the short circuit current. Spacer shall be suitable for the pressure and temperature of the service.
Fittings shall otherwise be as specified in this section.
3.1.3.20 Surface Treating, and Pipe Wrapping
Uninsulated steel piping buried in the ground shall have exterior surfaces protected with a tape wrapping system
or a continuously extruded polyethylene coating system as specified in Section 09 97 13.28 PROTECTION OF BURIED
STEEL PIPING AND STEEL BULKHEAD TIE RODS.
3.1.4 Painting
Unless specified otherwise, pipe hangers, structural supports, pipe and pipe fittings, conduit and conduit fittings,
air grilles, pipe coverings, insulation, and metal surfaces associated with mechanical and electrical equipment
including zinc-coated steel ducts shall be painted utilizing the painting systems as specified in Section
09 90 00 PAINTS AND COATINGS. Zinc-coated steel duct in unpainted areas shall not be painted. Piping to be insulated,
except zinc-coated and copper pipe, shall be given a protective coating prior to installing the insulation.
3.1.4.1 Piping, Fittings, and Mechanical and Electrical Equipment
Equipment shall be factory finished to withstand the intended end use environment in accordance with the specifications
for particular end item. Factory finished equipment on which the finish has been damaged shall have damaged
areas retouched and then be given a complete finish coat to restore the finish to its original condition. Finish
coat shall be suitable for exposure in the intended end use environment.
3.1.4.2 Boilers
After erecting and testing boilers, clean as necessary exposed surfaces of boiler normally painted in commercial
practice to remove grease, coal dust, flyash and other foreign matter and finish with one coat of aluminum heat
resisting paint applied to minimum dry film thickness of 0.025 mm one mil.
3.1.4.3 Vertical Fuel Oil Tank
Clean interior surfaces to bare metal in accordance with SSPC SP 10. Clean to bare metal by powered wire brushing
or other mechanical means surfaces that cannot be cleaned satisfactorily by blasting. Wash members which become
contaminated with rust, dirt, oil, grease, or other contaminants with solvents until thoroughly clean. Remove
weld backing plates prior to blast cleaning; when left in place, round off corners prior to blast cleaning and
coating. Internally coat tanks in accordance with Section 09 97 13.17 INTERIOR COATING OF WELDED STEEL PETROLEUM
FUEL TANKS.
3.1.4.4 Surfaces Not to be Painted
Unless specified otherwise, do not paint equipment having factory applied permanent finish, switchplates and
nameplates, motor starters, and concrete foundations.
3.1.5 Insulation
Insulate mechanical equipment, systems and piping as specified in Section 23 07 00 THERMAL INSULATION FOR MECHANICAL
SYSTEMS.
3.2 FIELD QUALITY CONTROL
Furnish labor, equipment, test apparatus required and materials for preparation and performance of tests and
inspections specified to demonstrate that the steam heating plant as installed, are in compliance with contract
requirements. During start-up and during tests, ensure the presence of factory trained engineers or technicians
employed by the boiler manufacturer and system suppliers of such components as the boiler, stoker, burner, combustion
controls, ash handling system, air pollution control system, feedwater treatment equipment, and other auxiliary
equipment, to ensure proper functioning, adjustment, and testing of the individual components and systems. Furnish
a detailed written record of test conditions, test procedures, field data, and the start-up and operational performance
of the entire heating plant to the Contracting Officer before the Contractor's operational and test personnel
leave the site. The Government will furnish, when available, water, electricity and fuel for the tests, except
fuel required for retesting. The Contractor shall rectify defects disclosed by the tests and retest the equipment.
The Contractor's boiler plant personnel shall be experienced in starting up and operating boiler plants.
3.2.1 Tests and Inspections (Piping)
Examine, inspect, and test piping in accordance with ASME B31.1 except as modified below. The Contractor shall
rectify defects disclosed by the tests. Necessary subsequent tests required to prove system tightness after
additional work by the Contractor shall be furnished by the Contractor. Make tests under the direction of and
subject to the prior approval of the Contracting Officer.
3.2.1.1 Hydrostatic and Leak Tightness Tests
a. Test piping systems attached to the boilers and included under the jurisdiction of ASME BPVC SEC I
in accordance with the requirement of that Code. Piping bearing ASME Code symbol stamp will
be accepted only as indicating compliance with the design and material requirements of the code.
b. Test piping which is a part of the steam generation or auxiliary systems, including piping
within the boiler room and external to the boiler room, by the following methods:
(1) Perform hydrostatic test at 150 percent of design pressure for welded and screwed steel
piping systems except those for air, oil, and gas. Hold hydrostatic tests for a period of one
hour with no pressure loss. Temperature of testing fluid shall not exceed 38 degrees C 100
degrees F.
(2) Test air and oil lines in accordance with the requirements of ASME B31.1 for pneumatic
tests with the exception that the test pressure must be held for one hour. Examine for leaks
by a soap or other foaming agent test.
(3) Inspection and test of gas piping shall conform to the requirements of NFPA 54.
c. For each test, install a calibrated test pressure gage in the system to observe loss in
pressure.
3.2.2 Preliminary Operation
The Contractor under the direction of the respective manufacturer's representative shall perform the work of
placing in operation equipment provided by the Contractor, except as specifically noted otherwise. Make adjustments
to equipment that are necessary to ensure proper operation as instructed by the manufacturer of the equipment.
a. Lubricate equipment prior to operation in accordance with the manufacturer's instructions.
Lubricants shall be provided by the Contractor. Contractor shall furnish lubrication gun with
spare cartridges of lubricant to operating personnel.
b. Dry out motors before operation as required to develop and maintain proper and constant
insulation resistance.
c. Check drive equipment couplings for proper alignment at both ambient and operating temperature
conditions.
3.2.3 General Startup Requirements
Prior to initial operation of complete system, check each component as follows:
a. Inspect bearings for cleanliness and alignment and remove foreign materials found. Lubricate
as necessary and in accordance with the manufacturer's recommendations. Replace bearings that
run roughly or noisily.
b. Adjust direct drives for proper alignment of flexible couplings. Provide lubrication when
a particular coupling so requires. Check security of couplings to driver shafts. Set drive
components to ensure free rotation with no undesirable stresses present on the coupling of attached
equipment.
c. Check motors for amperage comparison to nameplate value. Correct conditions that produce
excessive current flow and that exist due to equipment malfunction.
d. Check speeds of each motor and driven apparatus to ensure that they are operating at the
desired point.
e. Check the actual suction and discharge pressure of each pump against the desired performance
curves.
f. Check pump packing glands or seals for cleanliness and adjustment before running each pump.
Inspect shaft sleeves for scoring and proper placement of packing; replace when necessary.
Ensure piping system is free of dirt and scale before circulating liquid through pumps.
g. Inspect both hand and automatic control valves. Clean bonnets and stems, tighten glands
to ensure no leakage, but permit valve stems to operate without galling. Replace packing in
valves that require same to retain maximum adjustment after system is judged complete. Replace
entire packing in valves that continue to leak after adjustment. Remove and repair bonnets
that leak. Coat packing gland threads and valve stems with a suitable surface preparation after
cleaning.
h. Inspect and make certain that control valve seats are free from foreign material and are
properly positioned for the intended service.
i. Check flanges and packing glands after the system has been placed in operation. Replace
gaskets in flanges that show signs of leakage after tightening.
j. Inspect screwed joints for leakage and remake each joint that appears to be faulty. Do
not wait for rust to form. Clean threads on both parts, apply compound and remake joint.
k. Strainers installed shall be thoroughly blown out through individual valved blow-off connection
on each strainer prior to placing in operation.
l. Thoroughly blow out or dismantle and clean strainers after systems have been in operation
one week. Thoroughly clean, repair, and place back in service traps or other specialties in
which foreign matter has accumulated, causing malfunction or damage.
m. Adjust pipe hangers and supports for correct pitch and alignment.
n. Remove rust, scale and foreign materials from equipment and renew defaced surfaces. When
equipment is marred, the Contracting Officer shall have the authority to request that new materials
be provided.
o. Adjust and calibrate temperature, pressure and other automatic control systems.
p. Inspect each pressure gage and thermometer for calibration, and replace those that are defaced,
broken or read incorrectly.
q. Vertical Fuel Oil Tank Calibration: After completing installation of tank, prepare a calibration
table for the tank showing volume of fuel in liters gallons in tank to any height of liquid
in meters and mm feet, inches, and eighths of an inch when measured by a steel tape lowered
through the roof. Calibrate tank in accordance with ASTM D 1220 for "critical measurement"
"operating control." Correct the data obtained for use with the product to be stored.
3.2.4 Plant Equipment Tests
3.2.4.1 Plant Air Compressors
Test plant air compressors in service to determine compliance with contract requirements and warranty. During
the tests, test equipment under every condition of operation. Test safety controls to demonstrate performance
of their required function. Completely test system for compliance with specifications.
3.2.4.2 Coal Handling System
Test coal handling system under operating conditions and demonstrate that the work is in conformance with the
specified requirements. Conduct this test in the presence of the Contracting Officer.
3.2.4.3 Fuel Oil Tanks
NOTE: Choose one of following subparagraphs.
[a. Horizontal Fuel Oil Tanks (Below Ground)
(1) Test tanks before placing in service, in accordance with the applicable paragraphs of the
code under which they were built. A UL label, ASME Code Stamp, or API monogram on a tank shall
be evidence of compliance with code requirements.
(2) Holiday Detection Test: Inspect coal tar epoxy coating system for film imperfections using
a low voltage (75 volt) holiday tester. Inspect FRP coated tanks with a 10,000 volt spark test
for imperfections or holidays. Repair holidays or pinholes in the coatings.]
[b. Vertical Fuel Oil Tank: Inspect and test as specified in API Std 650. Use the radiographic
method of inspection of butt welds as required by API Std 650; sectioning method will not be
acceptable as an alternative to radiographic inspection.]
3.2.4.4 Blowdown Valves and Try Cocks
Test blowdown valves and try cocks for proper operation.
3.2.4.5 Fans, Heaters, Pumps, and Motors
Test draft fans, fuel oil heaters, fuel pumps, and electric motors to determine compliance with the referenced
standards. Standard symbols and certifications from the referenced organization may be accepted at the discretion
of the Contracting Officer. Closely observe the operation of fans, fuel oil heaters, fuel pumps, and electric
motors for possible defects or nonconformance.
3.2.5 Boilers and Auxiliaries Tests and Inspections
The Contractor, with qualified personnel provided by the Contractor, shall make tests and inspections at the
site under the direction of and subject to the approval of the Contracting Officer. Furnish direction of the
Contractor's boiler plant personnel in the operation of each boiler and appurtenances through the entire testing
period, from the respective manufacturer's representatives and consultants and ensure that necessary adjustments
have been made. The Contractor shall notify the Contracting Officer in writing at least 7 days in advance that
equipment is ready for testing. The Contractor shall furnish testing equipment, including gages, thermometers,
calorimeter, Orsat apparatus, thermocouple pyrometers, fuel flow meters, water meters and other test apparatus
and calibrate instruments prior to the test. Draft, fuel pressure and steam flow may be measured by permanent
gages and meters installed under the contract. The Contractor is responsible for providing an analysis of the
fuel being used for the tests. Control of noise levels developed by exhaust steam shall be as directed by the
Contracting Officer to satisfy the environmental conditions of the surrounding area. The Contractor shall perform
the following tests when feasible in the sequence as listed:
a. Strength and tightness tests
b. Standards compliance tests
c. Preliminary operational tests (steady state combustion test and variable load combustion
test)
d. Tests of auxiliary equipment
e. Feedwater equipment test
f. Capacity and efficiency tests
3.2.5.1 Strength and Leak Tightness Tests
Subject boilers to the following strength and tightness tests:
a. Watersides Including Fitting and Accessories: Hydrostatically test watersides in accordance
with the requirements of ASME BPVC SEC I The ASME label will be accepted as evidence of this
test.
b. Boiler Casing, Air Casing, and Ducts: Test air casing and ducts exterior to the furnace
pneumatically at the maximum working pressure. Use the soap bubble method to verify tightness.
Test gas sides of boilers normally operated under pressure for tightness at one and one half
times the predicted operating pressure in the furnace at maximum continuous output. For this
test, tightly seal the boiler with a suitable means to blank off openings. Admit air to the
boiler until the test pressure is reached, and then hold. When, in a 10 minute period the
pressure drop does not exceed 1245 Pa 5 inches water gage, the casing shall be regarded as tight
and accepted. Use air pressure and soap bubble tests or comparative carbon dioxide readings
for induced draft boilers.
3.2.5.2 Boiler Inspection
The Boiler Inspector shall be present to witness the appropriate tests which need to be observed in order to
certify the safety of the boiler. The inspection shall include the requirements of NAVFAC MO 324. The Boiler
Inspector shall complete NAVFAC form 9-11014/40, Data Record Sheet; NAVFAC form 9-11014/41, Inspection Report;
NAVFAC 9-11014/32 Inspection Certificate for each boiler after inspecting the boiler and finding it to be safe.
No boiler may be fired until it has passed the inspection of the Boiler Inspector. The boiler inspection forms
shall be submitted through the Contractor to the Contracting Officer. The Inspection Certificate shall be placed
under framed glass, mounted on or near the boiler in a conspicuous location.
3.2.5.3 Boiler Cleaning and Startup
Dry out, boil out, and operate the firing rate of the new boiler(s) under direct responsibility and supervision
of the manufacturer[, and in the presence of the boiler room operating personnel]. Provide chemicals that are
required. Allow sufficient time for the boiling out process to ensure interior surfaces are clean. This time
shall be at least 24 continuous hours and generally not more than 36 hours; boil out shall continue until water
is clear. Boil out, cleaning and starting procedures shall be in accordance with requirements of ASME BPVC SEC VII
, and FM DS 12-17.
3.2.5.4 Boiler Preliminary Operational Tests
Conduct a boiler operational test on each unit continuously for two weeks. Operate one boiler at a time to
demonstrate control and operational conformance to specified requirements including ability to respond to load
swings from the specified capacity to minimum turndown. Operational test shall be conducted under the supervision
of a registered professional engineer or a licensed power plant operator and shall serve to prove safeties, controls,
maintenance of stable combustion at low loads[, proper coal distribution and combustion, and ability to operate
without furnace slagging][, proper flame lengths and patterns to avoid flame impingement on the tubes for oil
firing], and proper mechanical and electrical functioning of systems. This test shall include each item mentioned
in this specification as well as each item mentioned in the specification of the particular pieces of equipment.
Conduct tests with factory trained combustion equipment engineers, as previously specified. Test and record
steam quality rates of steam flow, flue gas temperature, percentages of carbon dioxide, carbon monoxide, oxygen
and nitrogen in the flue gas and percent excess air for each boiler at tested load and graphically present test
data.
3.2.6 General Operational Tests
3.2.6.1 General Controls
Operational tests, performance tests, and demonstration tests shall be conducted with boiler controls functional
and on line. No bypassing, use of jumpers, or other disablement of control systems will be allowed unless specified
elsewhere.
3.2.6.2 Steady State Combustion Tests
Test fuel burning and combustion control equipment with each of the specific fuels at the minimum limit of the
turndown range and at increments of 50, 75 and 100 percent of full rated load. Each test run shall be at least
two hours on each fuel and until stack temperatures are constant and capacity and efficiency requirements of
this specification have been verified and recorded. Verify proper operation of instrumentation and gages during
the tests.
3.2.6.3 Varying Load Combustion Tests
Test boilers continuously under varying load conditions to demonstrate proper operability of the combustion control,
flame safeguard control, programming control and safety interlocks. Conduct these tests after adjustment of
combustion controls has been completed under the steady state combustion tests. Continue variable load operational
tests for a period of at least 8 hours.
a. Sequencing: Boiler shall start, operate and stop in strict accordance with the specified
operating sequence.
b. Flame Safeguard: Verify operation of flame safeguard controls by simulated flame and ignition
failures. Verify trial-for-pilot ignition, trial-for-main flame ignition, combustion control
reaction and valve closing times by stop watch.
c. Immunity to Hot Refractory: Operate burner at high fire until combustion chamber refractory
reaches maximum temperature. Main fuel valve shall then be closed manually. Combustion safeguard
shall drop out immediately causing safety shutoff valves to close within the specified control
reaction and valve closing times.
d. Pilot Intensity Required: Gradually reduce fuel supply to the pilot flame to the point
where the combustion safeguard begins to drop out (sense "no flame") but holds in until main
fuel valve opens. At this point of reduced pilot fuel supply, the pilot flame shall be capable
of safely igniting the main burner. When the main fuel valve can be opened on a pilot flame
of insufficient intensity to safely light the main flame, the boiler shall be rejected.
e. Boiler Limit and Fuel Safety Interlocks: Safety shutdown shall be caused by simulating
interlock actuating conditions for each boiler limit and fuel safety interlock. Safety shutdowns
shall occur in the specified manner.
f. Combustion Controls: Demonstrate accuracy, range and smoothness of operation of the combustion
controls by varying steam demand through entire firing range required by turndown ratio specified
for the burner. Control accuracy shall be as specified.
g. Safety Valves: High pressure limit switch shall be locked out or otherwise made inoperative
and the boiler safety valves shall be lifted by steam. Determine the relieving capacity, popping
pressure, blowdown and reseating pressure by observation and measurement in accordance with
the ASME BPVC SEC I. The ASME standard symbol will be accepted only as indicating compliance
with the design and material requirements of the code.
3.2.6.4 Auxiliary Equipment and Accessory Tests
Observe and test blowdown valves, stop valves, try cocks, draft fans, fuel oil heaters, pumps, electric motors,
and other accessories and appurtenant equipment during the operational and capacity tests for leakage, malfunctions,
defects, and for compliance with referenced standards.
3.2.6.5 Feedwater Equipment Tests
Perform the test of the feedwater treatment equipment in two steps. Conduct one test concurrently with the combustion
tests. The Government will perform a second test during the first period of heavy loading after the plant has
been accepted and put in service. Correct deficiencies revealed during the Government tests under the guarantee
provisions of the contract. Both the first and second series of tests shall determine compliance with the limits
for chemical concentrations of this specification. Supply equipment for taking samples and test kit for analyzing
samples. Sampling equipment and test kit shall become the property of the Government when tests are completed.
3.2.6.6 Capacity and Efficiency Tests
Perform capacity and efficiency tests after operating tests have been satisfactorily completed and boiler has
been operated continuously for at least 14 days with no nuisance shutdowns and without the necessity for frequent
or difficult adjustments. Perform these tests on each boiler. Conduct tests using [the] [each] specified fuel.
Test procedures shall be in accordance with the heat loss method [and the input-output method] of ASME PTC 4.
Before performing tests, the Contracting Officer and the Contractor shall reach agreement on those items identified
in ASME PTC 4 Section 3, paragraph 3.0l "Items on Which Agreement Shall be Reached." A test run shall not start
until the boiler and accessories have reached an equilibrium and stabilization condition for at least one hour
in duration. Duration of tests shall be sufficient to record necessary data but in no case shall each run be
less than [4] [10] [24] hours.
a. Accomplish maximum output testing by means of a single 2 hour run at 110 percent load on
the boiler under test. Calculate boiler efficiency, both input-output and heat loss, from the
consistent readings taken during the runs. Runs shall be made at four different loads 30, 50,
70, and 100 percent of boiler rating during which both heat loss and input-output data shall
be taken. Predict unmeasured losses used in conjunction with heat loss calculations and include
with equipment data when submitted for approval. Subsequent tests required because of failure
of the equipment to perform adequately during specified capacity and efficiency tests shall
be the financial responsibility of the Contractor, including the cost of fuel.
b. Should analysis of the coal being burned during performance tests vary from that specified
as the performance coal, the guarantees shall be adjusted in accordance with accepted engineering
practice to determine compliance. Carbon loss shall be determined in accordance with American
Boiler Manufacturers Association curves for carbon loss.
3.2.6.7 Temporary Waste Steam Connection
When necessary to obtain sufficient load for these tests, provide a temporary steam line at a point outside of
building. Provide necessary pipe, fittings, supports, anchors and appurtenances including a field fabricated
silencer as directed by the Contracting Officer. Remove temporary piping and silencer after tests have been
satisfactorily completed.
3.2.6.8 Fire Safety for Oil-Fired Boilers
Conduct tests as necessary to determine compliance with the applicable UL Safety Standards. The presence of
the applicable Underwriters' label may be accepted as evidence of compliance in this respect when equipment is
manufacturer's standard commercial product.
a. Oil-Fired Boilers: Meet test requirements of UL 726.
b. Oil Burners: Meet test requirements of UL 296.
3.2.6.9 Plant Acceptance Operation
NOTE: Include bracketed portion when project is for coal fired installation
with flue gas desulfurization system.
After satisfactory completion of tests specified, operate complete plant including each boiler [and its related
flue gas cleaning equipment] and subsystems for a period of 30 continuous 24 hour operational days prior to final
acceptance by the Government. Furnish labor, chemicals, test equipment and apparatus; the Government will furnish
fuel, electricity and water. During this 30 day period, furnish readily available, services of qualified representatives
from manufacturers of each plant component and system for the purpose of additional operational assistance, component
and system adjustment and repairs. Government personnel will observe Contractor's operational procedures. The
Contractor's representatives shall be prepared to answer pertinent questions from the Government about the plant
operation.
3.2.6.10 NAVFACENGCOM Acceptance
Operational, piping systems, auxiliary equipment and accessory testing shall be completed prior to requesting
an acceptance inspection by a Naval Facilities Engineering Command (NAVFACENGCOM) Boiler Inspector. The Contracting
Officer, upon receipt of 14 calendar days advance notice from the Contractor, shall request that the boiler plant
by a qualified NAVFACENGCOM Boiler Inspector. Contractor shall perform final operational performance testing
of all plant systems in the presence of the NAVFACENGCOM Boiler Inspector, at the inspector's discretion. The
NAVFACENGCOM Boiler inspector shall receive copies, and review the results, of all pertinent operational test
reports before approving acceptance of the boiler plant by the Government.
3.2.7 Manufacturer's Field Services
3.2.7.1 Erection/Installation Supervisors and Service Engineers
a. Boiler: Furnish the services of a competent supervisor who is in the direct employ of the
boiler manufacturer. This supervisor shall remain on the construction site the full 8 hours
per day, 5 days per week, or the same hours as the boiler erectors are on the job. This supervisor
shall be responsible for the complete steam generating unit, including the steam generator,
stoker, fans and related work, such as refractory, or insulation regardless of whether the stoker,
fans or other related items of work are furnished by manufacturers other than the boiler manufacturer.
b. Stoker: Furnish a competent erection supervisor for the equipment furnished by the stoker
manufacturer.
c. Fans: Furnish a company service engineer to advise on the erection or installation of fans
and related equipment.
d. Service Engineers: Furnish services of the manufacturing companies' service engineers and
the system suppliers' service engineers to advise during erection and installation of other
systems and equipment such as control system, ash handling system, coal handling system, air
compressors, air dryers, boiler feedwater pumps, fuel oil pumps, condensate pumps, water treatment
equipment, chemical feed pumps, deaerating feedwater heater and stacks.
3.2.7.2 Boiler and System Representatives
Furnish factory trained engineers or technicians who are representatives of the boiler manufacturer and system
supplier to supervise testing of the boilers and auxiliary equipment.
a. Furnish the services of a Boiler Inspector who is qualified and certified as such by the
National Board of Boiler and Pressure Vessel Inspectors and who is presently employed full time
by a firm, such as Hartford Steam Boiler Inspection and Insurance Company, which has a business
of inspecting boilers.
3.2.7.3 Instruction to Government Personnel
Supervisors and service engineers shall provide instruction for the Government's operators in the operation and
maintenance of the equipment furnished under this section. The minimum number of hours provided shall be as
follows:
Equipment Operation Instruction Maintenance Instruction
Boiler and auxiliaries 40 hours 16 hours
Stoker 40 hours 16 hours
F.D. and I.D. fans 16 hours 16 hours
Coal handling system 16 hours 32 hours
Ash handling system 24 hours 8 hours
Air compressors and dryers 8 hours 16 hours
Boiler feedwater pumps 8 hours 8 hours
Miscellaneous equipment 16 hours 16 hours