USACE / NAVFAC / AFCESA / NASA UFGS-23 25 00 (November 2008)
-----------------------------
Preparing Activity: USACE Superseding
UFGS-23 25 00 (April 2006)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 23 25 00
CHEMICAL TREATMENT OF WATER FOR MECHANICAL SYSTEMS
11/08
NOTE: This guide specification covers the requirements for chemical treatment
of water for mechanical systems.
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).
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.
[ASME INTERNATIONAL (ASME)ASME B40.100(2005) Pressure Gauges and Gauge Attachments][ASTM INTERNATIONAL (ASTM)ASTM D 1384(2005e1) Corrosion Test for Engine Coolants in GlasswareASTM D 2688(2005) Corrosivity of Water in the Absence of Heat Transfer (Weight Loss Methods)ASTM D 596(2001; R 2006) Reporting Results of Analysis of Water][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 Generators][U.S. ARMY CORPS OF ENGINEERS (USACE)PWTB 420-49-5(1998) Industrial Water Treatment Procedures][U.S. DEPARTMENT OF DEFENSE (DOD)UFC 3-230-08A(2004) Water Supply: Water Treatment]1.2 SYSTEM DESCRIPTION
This section covers the provisions and installation procedures necessary for a complete and totally functional
water system(s) chemical treatment. Provide and install the system with all necessary System Components, Accessories,
Piping Components, and Supplemental Components/Services.
1.3 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.][information only. When used, a designation following the "G"
designation identifies the office that will review the submittal for the Government.] Submit the following in
accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-03 Product Data
Water Treatment System[; G][; G, [_____]]
Water Analysis[; G][; G, [_____]]
[Six] [_____] complete copies, at least 5 weeks prior to the purchase of the water treatment
system, of the proposed water treatment plan including a layout; control scheme; a list of existing
make-up water chemistry, including the items listed in paragraph Water Analysis; a list of treatment
chemicals to be added; the proportion of chemicals to be added; the final treated water control
levels; and a description of health, safety and environmental concerns for handling the chemicals
plus any special ventilation requirements.
Spare Parts
Spare parts data for each different item of material and equipment specified.
Field Instructions
Instructions, at least 2 weeks prior to construction completion, including equipment layout,
wiring and control diagrams, piping, valves and control sequences, and typed condensed operation
instructions. The condensed operation instructions shall include preventative maintenance procedures,
methods of checking the system for normal and safe operation, and procedures for safely starting
and stopping the system. The posted instructions shall be framed under glass or laminated plastic
and posted where indicated by the Contracting Officer.
Tests[; G][; G, [_____]]
Test schedules, at least 2 weeks prior to the start of related testing, for the condenser/chilled/boiler/condensate/feedwater
water quality tests. The schedules shall identify the date, time, frequency and collection
location for each test.
Demonstrations[; G][; G, [_____]]
A schedule, at least 2 weeks prior to the date of the proposed training course, which identifies
the date, time, and location for the training.
SD-06 Test Reports
Condenser Water Quality Assurance Tests
Test reports in bound 216 by 279 mm 8-1/2 by 11 inch booklets. The reports shall identify
the chemical composition of the condenser water. The reports shall also include a comparison
of the manufacturer's or chemical vendor's recommended operating conditions for the cooling
tower and condenser in relation to the actual condition of the condenser water. Any required
corrective action shall be documented within the report.
Steam Boiler Water Quality Assurance Tests
The water quality test report identifying the chemical composition of the boiler, feedwater
and condensate water. The report shall include a comparison of the condition of the boiler
water with the manufacturer's or chemical vendor's recommended conditions. Any required corrective
action shall be documented within the report.
SD-10 Operation and Maintenance Data
Water Treatment System
[Six] [_____] complete copies of operating and maintenance manuals for the step-by-step water
treatment procedures. The manuals shall include testing procedures used in determining water
quality.
1.4 QUALITY ASSURANCE
1.4.1 Safety
NOTE: Catwalk, ladder and guardrail may be required. If so, select the applicable
item and delete the others and indicate on drawings the selected item. If not
applicable, delete the entire sentence within the brackets.
Exposed moving parts, parts that produce high operating temperature, parts which may be electrically energized,
and parts that may be a hazard to operating personnel shall be insulated, fully enclosed, guarded, or fitted
with other types of safety devices. Install safety devices so that proper operation of equipment is not impaired.
Provide [catwalk,] [ladder,] [and guardrail] where indicated and in accordance with Section [05 50 13 MISCELLANEOUS
METAL FABRICATIONS] [05 51 33 METAL LADDERS].
1.4.2 Drawings
Because of the small scale of the drawings, it is not possible to indicate all offsets, fittings, and accessories
that may be required. Carefully investigate the plumbing, fire protection, electrical, structural and finish
conditions that would affect the work to be performed and arrange such work accordingly, furnishing required
offsets, fittings, and accessories to meet such conditions.
1.5 DELIVERY, STORAGE, AND HANDLING
Protect all equipment delivered and placed in storage from the weather, humidity and temperature variations,
dirt and dust, or other contaminants.
1.6 MAINTENANCE
Submit spare parts data for each different item of material and equipment specified, after approval of the detail
drawings, not later than [_____] months prior to the date of beneficial occupancy. The data shall include a
complete list of parts and supplies, with source of supply
PART 2 PRODUCTS
2.1 STANDARD PRODUCTS
a. Provide materials and equipment which are standard products of a manufacturer regularly engaged in
the manufacturing of such products, that are of a similar material, design and workmanship and that have
been in satisfactory commercial or industrial use for two years prior to bid opening.
b. The two-year use shall include applications of equipment and materials under similar circumstances
and of similar size. The two years experience shall have been satisfactorily completed by a product
which has been sold or is offered for sale on the commercial market through advertisements, manufacturer's
catalogs, or brochures. Products having less than a two-year field service record will be acceptable
if a certified record of satisfactory field operation, for not less than 6000 hours exclusive of the
manufacturer's factory tests, can be shown.
c. All products shall be supported by a service organization. Submit a certified list of qualified
permanent service organizations for support of the equipment, including their addresses and ualifications.
These service organizations shall be reasonably convenient to the equipment installation and shall be
able to render satisfactory service to the equipment on a regular and emergency basis during the warranty
period of the contract.
d. The selected service organization shall provide the chemicals required, the concentrations required,
and the water treatment equipment sizes and flow rates required. The company shall provide all chemicals
required for the [condenser] [condenser and chilled] water systems and fill the systems with chemicals
to the levels specified. The chemical shall meet the requirements of this specification as well as the
recommendations from the manufacturers of the condenser and cooling tower. Acid treatment chemicals
shall not be used.
2.2 NAMEPLATES
Each major component of equipment shall have the manufacturer's name, address, type or style, and catalog or
serial number on a plate securely attached to the item of equipment. Nameplates shall be provided for:
a. Pump(s)
b. Pump Motor(s)
2.3 ELECTRICAL WORK
NOTE: Where motor starters for mechanical equipment are provided in motor-control
centers, the references to motor starters will be deleted. Mechanical designer
must ensure that the electrical designer is provided with electrical requirements
for chemical feed pumps.
Electrical equipment, motors, motor efficiencies, and wiring shall be in accordance with Section 26 20 00 INTERIOR
DISTRIBUTION SYSTEM. Provide electrical motor driven equipment specified complete with motors, motor starters,
and controls. Electrical characteristics and enclosure type shall be as shown, and unless otherwise indicated,
all motors of 745 W 1 horsepower and above with open, dripproof, or totally enclosed fan cooled enclosures, shall
be high efficiency type. Field wiring shall be in accordance with manufacturer's instructions. Each motor shall
conform to NEMA MG 1 and be of sufficient size to drive the equipment at the specified capacity without exceeding
the nameplate rating of the motor. All motors shall be continuous duty with the enclosure specified. Provide
motor starters complete with thermal overload protection and other appurtenances necessary for the motor control
indicated. Furnish motors with a magnetic across-the-line or reduced voltage type starter as required by the
manufacturer. Motor starter shall be provided with [NEMA 1] [NEMA 3R] [NEMA [_____]] enclosures. Manual or
automatic control and protective or signal devices required for the operation specified and any control wiring
required for controls and devices specified, but not shown, shall be provided.
2.4 GAUGES
Gauges shall conform to ASME B40.100, Class 1, 2, or 3, Style X, Type I or III as required, 115 mm 4-1/2 inches
in diameter with phenolic or metal case.
2.5 WATER ANALYSIS
NOTE: A water analysis may be available from the user. If an analysis is not
available, an analysis will be performed during the design, and appropriate
data will be entered.
Cooling towers with a capacity greater than 176 kW (50 tons) will be provided
with automatic chemical feed and blow down systems. Smaller towers will be
provided with continuously activated systems. Indicate the location of the
entire water treatment system. Delete all the information under this paragraph
if a cooling tower is not used in the system.
Conditions of make-up water to be supplied to the boilers, cooling towers and chilled water systems reported
in accordance with ASTM D 596 are as follows:
Date of Sample [_____]
Temperature [_____] degrees C.
Silica (SiO 2) [_____] ppm (mg/L)
Insoluble [_____] ppm (mg/L)
Iron, total (Fe) [_____] ppm (mg/L)
Aluminum (Al) [_____] ppm (mg/L)
Calcium (Ca) [_____] ppm (mg/L)
Magnesium (Mg) [_____] ppm (mg/L)
Carbonate (HCO 3) [_____] ppm (mg/L)
Sulfate (SO 4) [_____] ppm (mg/L)
Chloride (Cl) [_____] ppm (mg/L)
Nitrate (NO 3) [_____] ppm (mg/L)
Turbidity [_____] ntu
pH [_____]
Residual Chlorine [_____] ppm (mg/L)
Total Alkalinity [_____] ppm (mg/L)
Non-Carbonate Hardness [_____] ppm (mg/L)
Total Hardness [_____] ppm (mg/L)
Dissolved Solids [_____] ppm (mg/L)
Conductivity [_____] micromho/cm
2.6 CONDENSER WATER TREATMENT SYSTEMS
The use of chemical-treatment products containing hexavalent chromium (Cr) is prohibited. Treat rhe water to
be used in the condenser water systems to maintain the conditions recommended by this specification as well as
the recommendations from the manufacturers of the condenser and evaporator coils. Chemicals shall meet all required
federal, state, and local environmental regulations for the treatment of condenser-side heat exchangers, cooling
towers and direct discharge to the sanitary sewer.
2.6.1 Condenser Water Limits
The condenser water limits shall be as follows, unless dictated differently by the cooling tower or chiller manufacturer's
recommendations:
Treatment type Phosphonate/Polymer
Puckorius Index 4 minimum
Langelier Index 4 maximum
Total Dissolved Solids 5000 ppm maximum
Calcium Hardness 1200 ppm maximum
Silica 150 ppm maximum
PH 7.5 - 8.5
For treated condenser/cooling tower water, blowdown must be minimized until the first of one of the top 5 limits
is reached. Specific requirements for treatment chemicals and levels are listed below in paragraphs dealing
with small and large systems.
2.6.2 Glycol Solution
NOTE: If freeze protection for condenser water is not required, this paragraph
should be deleted. When a glycol system is used, the size of the HVAC systems
should be corrected due to changes in specific heat and viscosity. ASHRAE's
"HVAC systems and Equipment Handbook" should be consulted for the appropriate
calculation procedures. Ethylene glycol should be used for HVAC systems. However,
if the heat transfer media has the possibility of mixing with a potable water
system, propylene glycol should be used. The required concentration should
be entered based upon the anticipated ambient or operating temperature.
Provide for the system a [_____] percent concentration by volume of industrial grade [ethylene] [propylene] glycol,
and corrosion inhibitors. Test the glycol in accordance with ASTM D 1384 with less than 0.013 mm 0.5 mils penetration
per year for all system metals. The glycol shall contain corrosion inhibitors. Silicate based inhibitors are
not acceptable. The solution shall be compatible with pump seals, other elements of the system, and water treatment
chemicals used within the system.
2.6.3 Chemical Treatment for Small Systems
For cooling systems with a capacity of 175.8 kW 50 tons or less, provide the following chemical treatment. For
corrosion control provide 6.8 to 9.1 kg 15 to 20 pounds polyphosphate in nylon mesh bag in cooling tower sump.
If biocide is needed, use either 1-bromo-3-chloro-5.5-dimethylhydantoin or gluteraldehyde as recommended by manufacturer.
2.6.4 Chemical Treatment for Large Systems
For cooling systems with capacities greater than 175.8 kW 50 tons provide one of the three following chemical
treatments with the limits indicated. The zinc and molybdate in the last two treatments help to meet the maximum
corrosion requirements in waters that tend to be more corrosive. Biocides must be maintained to control bacteria
below 10,000 colony forming units per milliliter.
a. Phosphonate Type Treatment
Phosphonate (3-5 ppm)
Polymer (3-4 ppm)
TT (1-2 ppm)
Biocides as required
b. Zinc-Phosphonate Type Treatment
Phosphonate (3-5 ppm)
Polymer (3-4 ppm)
Zinc (1-2 ppm)
TT (1-2 ppm)
Biocides as required
c. Zinc-Molybdate Type Treatment
Phosphonate (3-5 ppm)
Polymer (3-4 ppm)
Molybdate (10-15 ppm)
Zinc (2-3 ppm)
TT (1-2 ppm)
Biocides as required
2.6.4.1 General Requirements
Provide a water treatment system capable of automatically feeding chemicals and bleeding the system to prevent
corrosion, scale, and biological formations. Automatic chemical feed systems shall automatically feed chemicals
into the condenser water based on makeup water rate. Electrical signals from a water meter on the makeup water
line shall be used to control the output of chemical feed pumps. The system shall be initially set manually
based on the water analysis of the make-up water.
2.6.4.2 Chemical Feed Pumps and Tanks
NOTE: The required maximum pump flow rate will be shown on the drawings. The
flow rate will depend upon the makeup water flow rate, the chemical composition
of the makeup water and the concentration of the chemical supplied. A water
treatment company should be consulted for determining the proper maximum pump
flow rate.
A water treatment company will be consulted to determine the number of tanks
required and shall be shown on plans. The number will depend on the size of
the boiler, makeup water flow rate, and makeup water composition. A potable
water line will be provided near the tanks for the mixing of chemicals.
a. Furnish chemical feed pumps and tanks as a package with the pumps mounted on and piping connected
to the tank. The chemical feed pumps shall be positive displacement diaphragm type. The pump's cylinders,
plungers, ball check valves, and check valve bodies shall be of corrosion resistant materials suitable
for the chemicals being pumped. Cylinders shall be replaceable for increased or reduced pressure or
capacity ranges.
b. The flow rate of the pumps shall be adjustable from 0 to 100 percent while in operation. Volumetric
accuracy of the pumps shall be within one percent over the range indicated. Pump capacities shall be
adjustable by positioning crank pin with micrometer setscrews. Stroke length scale shall be divided
in percentage graduations engraved on scale. The discharge pressure of pumps shall not be less than
1.5 times the line pressure at the point of connection. The pumps shall be provided with a pressure
relief valve and a check valve mounted in the pump discharge. The pumps shall be controlled by an external
controller/timer receiving signals from the makeup water meter.
c. Drive motors shall be 110 volt, single phase and shall have drip-proof enclosures. Provide two chemical
tanks. The tanks shall be constructed of [materials compatible with the chemicals to be stored in the
tank] [high density polyethylene] [stainless steel] [fiber reinforced plastic] with a hinged cover and
mounted on legs. Tanks shall have filling and drain connections and gauge glass. Each tank shall be
furnished with one pump, mounted and piped with black iron pipe and fittings, with suction strainer and
stainless steel screen, and with 13 mm 1/2 inch relief valve with steel body and stainless steel trim.
Tank bottom shall be dished concave to a radius equal to the diameter of the tank. Motor-driven agitator
shall be provided. The tanks shall have sufficient capacity to require recharging only once per [7]
[14] [21] [_____] days during normal operation.
2.6.4.3 Chemical Injection Assembly
Provide an injection assembly at each chemical feed point. Locate the injection assembly downstream of recirculating
pumps and upstream of the condenser. The injection assemblies shall be constructed of stainless steel. The
discharge of the assemblies shall extend to the centerline of the condenser water piping. Each assembly shall
include a shutoff valve and check valve at the point of entrance into the condenser water line.
2.6.4.4 Water Meter
Provide water meters with an electric contacting register and remote accumulative counter. Install the meter
within the make-up water line, as indicated.
2.6.4.5 Timers
Timers shall be of the automatic reset, adjustable type, and electrically operated. The timers shall be designed
to work with the contacting head water meters. The timer should include the water meter cable. The timers will
control operation of the chemical feed pumps. The timers shall be suitable for a 120 volt current. The timers
shall be located within the water treatment control panel.
2.6.4.6 Bleed (Blowdown) Line
Control the flow through the bleed line by a conductivity meter and probe installed to measure the conductivity
of the condenser water. The conductivity meter shall have a high and low set point above which the conductivity
meter shall open a solenoid valve on the bleed line. The bleed line attachment to the condenser water piping
shall be located downstream of the recirculating pumps and upstream of the chemical injection point. The bleed
line shall be extended to the nearest drain for continuous discharge.
2.6.4.7 Control Panel
NOTE: The MAN-OFF-AUTO switch should be deleted for continuously fed systems.
In areas where a panel could come in contact with the water treatment chemical,
choose the stainless steel construction.
The control panel shall be a NEMA 12 enclosure suitable for surface mounting. The panel shall be constructed
of [stainless steel] [coated steel] with a hinged door and lock. The panel shall contain a laminated plastic
nameplate identifying each of the following functions:
(1) Main power switch and indicating light
(2) MAN-OFF-AUTO selector switch
(3) Indicating lamp for bleed-off valve
(4) Indicating lamp for each chemical feed pump
(5) Set point reading for each timer
2.6.4.8 Chemical Piping
The piping and fittings shall be constructed of [schedule 80 PVC] [stainless steel] suitable for the water treatment
chemicals.
2.6.4.9 Sequence of Operation
The chemicals shall be added based upon sensing the make-up water flow rate and activating appropriate timers.
A separate timer shall be provided for each chemical. The blow down shall be controlled based upon the conductivity
of the condenser water. The injection of the chemical required for biological control shall be controlled by
a timer that can be manually set for proper chemical feed. All timer set points, blow down rates, and chemical
pump flow rates shall be determined and set by the water treatment company.
2.6.4.10 Test Kits
One test kit of each type required to determine the water quality as outlined within the operation and maintenance
manuals shall be provided.
2.7 CHILLED WATER SYSTEM
NOTE: The services of a company regularly engaged in water treatment for mechanical
systems to treat a chilled water system should only be required if the makeup
water available is of very poor quality.
For dual temperature systems (chilled and heated water), coordinate the compatibility
of the separate water treatment systems.
A [7.57] [18.92] [_____] L [2] [5] [_____] gallon shot feeder shall be provided on the chilled water piping as
indicated. The feeder shall be furnished with an air vent, gauge glass, funnel, valves, fittings, and piping.
2.7.1 Requirements for Glycol Solution
NOTE: If freeze protection for chilled water is not required, this paragraph
should be deleted. When a glycol system is used, the size of the HVAC systems
should be corrected due to changes in specific heat and viscosity. ASHRAE's
"HVAC systems and Equipment Handbook" should be consulted for the appropriate
calculation procedures. Ethylene glycol should be used for HVAC systems. However,
if the heat transfer media has the possibility of mixing with a potable water
system, propylene glycol should be used. The required concentration should
be entered based upon the anticipated ambient or operating temperature.
Provide a [_____] percent concentration by volume of industrial grade [ethylene] [propylene] glycol, and corrosion
inhibitors, for the system. Test the glycol in accordance with ASTM D 1384 with less than 0.013 mm 0.5 mils
penetration per year for all system metals. The glycol shall contain corrosion inhibitors. Silicate based inhibitors
shall not be used. The solution shall be compatible with pump seals, other elements of the system, and water
treatment chemicals used within the system.
2.7.2 Chilled Water Treatment
Treat chilled water with either a borax/nitrite type treatment or a molybdate type treatment. Both types of
treatment can be used with glycol. Borax/nitrite treatment shall be maintained at the limits of 600 to 1000
ppm nitrite, 40 - 50 ppm copper corrosion inhibitor (TT or MBT), and pH of 8.5 to 9.5. Molybdate treatment shall
be maintained at the limits of 100 to 125 ppm molybdate, 40 - 50 ppm copper corrosion inhibitor (TT or MBT),
and pH of 8.0 to 9.0.
2.7.3 Dual Temperature Systems
Dual hot/chilled water systems treated with borax/nitrite shall also be treated with a biocide.
2.7.4 Chilled Water Test Kits
One test kit of each type required to determine the water quality as outlined within the operation and maintenance
manuals shall be provided (e.g. pH and nitrite or molybdate).
2.8 LOW AND MEDIUM TEMPERATURE HOT WATER BOILERS AND HEAT EXCHANGERS
Low and medium temperature hot water boilers are defined as those operating below 177 degrees C 350 degrees F
, (122 degrees C 250 degrees F for Low Temperarure).
2.8.1 Chemical Feeder
A [7.57] [18.92] [_____] L [2] [5] [_____] gallon shot feeder shall be provided on the hot water piping as indicated.
Size and capacity of feeder shall be based on local requirements and water analysis. The feeder shall be furnished
with an air vent, gauge glass, funnel, valves, fittings, and piping.
2.8.2 Water Softening System
NOTE: The makeup water analysis and the boiler manufacturer's recommended feed
water conditions will be used to determine the need for a water softener. UFC
3-230-08A contains general guidance for the selection. Softening of makeup
water for hot water boilers is required if the makeup water hardness is above
200 ppm or the makeup rate is above 1%.
The water softening system shall be as specified in Section 22 31 00 WATER SOFTENERS, CATION-EXCHANGE (SODIUM
CYCLE).
2.8.3 Low and Medium Temperature Hot Water Treatment
Hot water shall be treated with either a borax/nitrite type treatment or a molybdate type treatment. Both types
of treatment can be used with glycol. Borax/nitrite treatment shall be maintained at the limits of 600 to 1000
ppm nitrite, 40 - 50 ppm copper corrosion inhibitor (TT or MBT) and pH of 8.5 to 9.5. Molybdate treatment shall
be maintained at the limits of 100 to 125 ppm molybdate, 40 - 50 ppm copper corrosion inhibitor (TT or MBT) and
pH of 8.0 to 9.0.
2.8.4 Dual Temperature Systems
Dual hot/chilled water systems treated with borax/nitrite shall also be treated with a biocide.
2.8.5 Test Kit Requirements
One test kit of each type required to determine the water quality as outlined within the operation and maintenance
manuals shall be provided (e.g. pH and nitrite or molybdate).
2.9 HIGH TEMPERATURE HOT WATER BOILERS
High Temperature Hot Water Boilers are defined as those operating above 177
degrees C (350 deg F). The chemical treatment requires more attention (daily),
the makeup water requires softening and the chemicals and limits differ from
the low and medium temperature hot water boilers.
2.9.1 Chemical Feeder Unit
NOTE: The required maximum pump flow rate will be shown on the drawings. The
flow rate will depend upon the makeup water flow rate, the chemical composition
of the makeup water and the concentration of the chemical supplied. A water
treatment company should be consulted for determining the proper maximum pump
flow rate.
A company regularly engaged in water treatment for mechanical systems will be
consulted to determine the number of tanks required to be shown on the drawings.
The number will depend on the size of the boiler, makeup water flow rate, and
makeup water composition. A potable water line will be provided near the tanks
for the mixing of chemicals.
A feeder unit shall be provided for each boiler. Chemical feeder shall be automatic proportioning, shot type,
or pump type. All appurtenances necessary for satisfactory operation shall be provided. Size and capacity of
feeder shall be based upon local requirements and water analysis.
2.9.2 Pumps and Tanks
a. Furnish chemical feed pumps and tanks as a package with the pumps mounted on and piping connected
to the tank. The chemical feed pumps shall be positive displacement diaphragm type. The pump cylinders,
plungers, ball check valves, and check valve bodies shall be of corrosion resistant materials suitable
for the chemicals being pumped. Cylinders shall be replaceable for increased or reduced pressure or
capacity ranges.
b. The flow rate of the pumps shall be adjustable from 0 to 100 percent while in operation. Volumetric
accuracy of the pumps shall be within one percent over the range indicated. Pump capacities shall be
adjustable by positioning crank pin with micrometer setscrews. Stroke length scale shall be divided
in percentage graduations engraved on scale. The discharge pressure of pumps shall not be less than
1.5 times the line pressure at the point of connection. The pump shall be designed to feed the chemical
solutions into the HTW return line to the system circulating pumps and shall have capacity to feed a
maximum of [5.3] [_____] mL/second [5] [_____] gph. The pumps shall be provided with a pressure relief
valve and a check valve mounted in the pump discharge. The pumps shall be controlled by an external
controller/timer receiving signals from the makeup water meter.
c. Drive motors shall be 110 volt, single phase and shall have drip-proof enclosures. The tanks shall
be constructed of [materials compatible with the chemicals to be stored in the tank] [high density polyethylene]
[stainless steel] [fiber reinforced plastic] with a hinged cover and mounted on legs. Tanks shall have
filling and drain connections and gauge glass. Each tank shall be furnished with one pump, mounted and
piped with black iron pipe and fittings, with suction strainer and stainless steel screen, and with 13
mm 1/2 inch relief valve with steel body and stainless steel trim. Tank bottom shall be dished concave
to a radius equal to the diameter of the tank. Units shall be for phosphate, caustic feed and sulfite
feeding. Sulfite tank shall have a floating cover to completely cover the surface of the solution.
Motor-driven agitator shall be provided. The tanks shall have sufficient capacity to require recharging
only once per [7] [14] [21] [_____] days during normal operation.
2.9.3 Water Softening System
NOTE: The makeup water analysis and the boiler manufacturer's recommended feed
water conditions will be used to determine the need for a water softener. UFC
3-230-08A contains general guidance for the selection. Hardness must be maintained
below 2 ppm.
The water softening system shall be as specified in Section 22 31 00 WATER SOFTENERS, CATION-EXCHANGE (SODIUM
CYCLE).
2.9.4 Treated Water Limits
The boiler manufacturer shall be consulted for the determination of the boiler water chemical composition limits.
The recirculating hot water chemical limits shall be as follows unless dictated differently by the boiler manufacturer's
recommendations:
PH 9.3-9.9
Sulfite 30-60 ppm
Hardness Less than 2.0 ppm
2.10 Test Kit
One test kit of each type required to determine the water quality as outlined within the operation and maintenance
manuals shall be provided (e.g. pH, hardness and sulfite).
2.11 STEAM BOILER WATER TREATMENT
NOTE: The chemical piping will be indicated on the drawing. Piping for feeding
sulfite will be connected to the storage section of the deaerator or feedwater
heater or to the feedwater line. Piping for other treatment chemicals will
be connected to the boiler drum. The chemical shot feeder will not be required
for larger steam boilers.
If steam is used for cooking or humidification, a separate heat exchanger will
be required due to environmental constraints with the use of amines (AR 420-49,
6-5b).
Provide a water treatment system capable of feeding chemicals and blowdown of the system to prevent corrosion
and scale within the boiler and piping distribution system. Treat the water to maintain the conditions recommended
by the boiler manufacturer or UFC 3-230-08A (Central Boiler Plants) and PWTB 420-49-5 (Industrial Water Treatment
Procedures). Chemicals shall meet required federal, state, and local environmental regulations for the treatment
of boilers and discharge to the sanitary sewer. The services of a company regularly engaged in the treatment
of boilers shall be used to determine the correct concentrations required for water treatment. The company shall
maintain the chemical treatment and provide all chemicals required for a period of 1 year from the date of occupancy.
Filming amines, hydrazine and chelants shall not be used. The water treatment chemicals shall remain stable
throughout the operating temperature range of the system and shall be compatible with pump seals and other elements
of the system.
2.11.1 Boiler Water Limits
The boiler water limits shall be as follows unless dictated differently by the boiler manufacturer's recommendations:
Causticity (OH) 20-200 ppm
Total Alkalinity (CaCO3) 200-800 ppm
Phosphate (PO4) 30-60 ppm
Polymer (dispersant) or Tannin 5-10 ppm or medium color,
respectively
Dissolved Solids (water tube boilers) 3000-3500 ppm
Dissolved Solids (fire tube boilers) 3500-5000 ppm
Suspended Solids 15 ppm Maximum
Sodium Sulfite 20-40 ppm
Silica Less than 200 ppm
Dissolved Oxygen Less than 7 ppb
Iron Less than 10 ppm
pH (Condensate) 7.5 - 8
Conductivity (Condensate) Less than 35 micromhos
Hardness (Condensate and makeup) Less than 2 ppm
The above limits apply to boilers operating above 100 kPa 15 psi up 2070 kPa 300 psi. Above 2070 kPa 300 psi
these limits decrease. Use ABMA or chemical vendor recommended limits above 2070 kPa 300 psi.
2.11.2 Water Softening System
NOTE: The makeup water analysis and the boiler manufacturer's recommended feed
water conditions will be used to determine the need for a water softener. UFC
3-230-08A contains general guidance for the selection. Generally, all boilers
operating above 100 kPa (15 psi) require softened water.
The water softening system shall be as specified in Section 22 31 00 WATER SOFTENERS, CATION-EXCHANGE (SODIUM
CYCLE).
2.11.3 Boiler Water Treatment System
The water treatment system shall be capable of automatically feeding chemicals to prevent corrosion and scale
within the boiler and condensate system. Automatic chemical feed systems shall feed chemicals into the boiler
based on makeup water rate. Electrical signals from a water meter on the makeup water line shall be used to
control the output of chemical feed pumps.
2.11.4 Steam Boiler Chemical Feed Pumps and Tanks
NOTE: The required maximum pump flow rate will be shown on the drawings. The
flow rate will depend upon the makeup water flow rate, the chemical composition
of the makeup water and the concentration of the chemical supplied. A water
treatment company should be consulted for determining the proper maximum pump
flow rate.
A company regularly engaged in water treatment for mechanical systems will be
consulted to determine the number of tanks required to be shown on the drawings.
The number will depend on the size of the boiler, makeup water flow rate, and
makeup water composition. A potable water line will be provided near the tanks
for the mixing of chemicals.
a. Furnish chemical feed pumps and tanks as a package with the pumps mounted on and piping connected
to the tank. The chemical feed pumps shall be positive displacement diaphragm type. The pump cylinders,
plungers, ball check valves, and check valve bodies shall be of corrosion resistant materials suitable
for the chemicals being pumped. Cylinders shall be replaceable for increased or reduced pressure or
capacity ranges. The flow rate of the pumps shall be adjustable from 0 to 100 percent while in operation.
Volumetric accuracy of the pumps shall be within one percent over the range indicated. Pump capacities
shall be adjustable by positioning crank pin with micrometer setscrews. Stroke length scale shall be
divided in percentage graduations engraved on scale.
b. The discharge pressure of pumps shall not be less than 1.5 times the line pressure at the point of
connection. The pumps shall be provided with a pressure relief valve and a check valve mounted in the
pump discharge. The pumps shall be controlled by an external controller/timer receiving signals from
the makeup water meter.
c. Drive motors shall be 110 volt, single phase and shall have drip-proof enclosures. The tanks shall
be constructed of [materials compatible with the chemicals to be stored in the tank] [high density polyethylene]
[stainless steel] [fiber reinforced plastic] with a hinged cover and mounted on legs. Tanks shall have
filling and drain connections and gauge glass. Each tank shall be furnished with one pump, mounted and
piped with black iron pipe and fittings, with suction strainer and stainless steel screen, and with 13
mm 1/2 inch relief valve with steel body and stainless steel trim. Tank bottom shall be dished concave
to a radius equal to the diameter of the tank. The tank for sodium sulfite will have a floating cover
to minimize contact with air. Motor-driven agitator shall be provided. The tanks shall have sufficient
capacity to require recharging only once per [7] [14] [21] [_____] days during normal operation.
2.11.5 Steam Boiler Chemical Injection Assemblies
Provide an injection assembly at each chemical injection point located along the boiler piping as indicated.
The injection assemblies shall be constructed of stainless steel. The discharge of the assemblies shall extend
to the centerline of the piping. Each assembly shall include a shutoff valve and check valve at the point of
entrance into the water line.
2.11.6 Steam Boiler Water Meter
Provide the water meter with an electric contacting register and remote accumulative counter. Install the meter
within the makeup water line, as indicated.
2.11.7 Steam Boiler Timers
Timers shall be of the automatic reset, adjustable type, and electrically operated. The timers shall be designed
to work with the contacting head water meters. The timer should include the water meter cable. The timers will
control operation of the chemical feed pumps. The timers shall be suitable for a 120 volt current. The timers
shall be used to control the electrical signals from the water meters to the chemical feed pumps.
2.11.8 Steam Boiler Control Panel
NOTE: The MAN-OFF-AUTO switch should be deleted for continuously fed systems.
The control panel shall be a NEMA 12, single door, wall-mounted box conforming with NEMA 250. The panel shall
be constructed of [coated steel] [stainless steel] with a hinged door and lock. The panel shall contain, as
a minimum, the following functions identified with a laminated plastic nameplate:
a. Main power switch and indicating light
b. MAN-OFF-AUTO selector switch
c. Indicating lamp for each chemical feed pump
d. Indicating lamp for the water softener
2.11.9 Boiler Blowdown
NOTE: Typically, automatic blowdown will be economical for boilers with capacities
greater than 2.9 MW (10,000,000 Btuh).
Provide the boiler with [continuous blowdown] [automatic blowdown based upon conductivity or boiler load]. Bottom
blowdown connection and valve shall also be present to allow removal of solids and water from the bottom of the
boiler.
2.11.10 Boiler Chemical Piping
NOTE: If steel piping is selected, an interior coating may be required depending
upon the chemicals used.
The piping and fittings shall be constructed of [steel] [stainless steel].
2.11.11 Boiler Test Kits
One test kit of each type required to determine the water quality as outlined in paragraph Boiler Water Limits
above and within the operation and maintenance manuals.
2.12 SUPPLEMENTAL COMPONENTS/SERVICES
NOTE: All drain and makeup water piping should be indicated on the drawings.
Drain and makeup water piping shall comply with the requirements of Section 22 00 00 PLUMBING, GENERAL PURPOSE.
Drains which connect to sanitary sewer systems shall be connected by means of an indirect waste.
PART 3 EXECUTION
3.1 EXAMINATION
After becoming familiar with all details of the work, verify all dimensions in the field, and advise the Contracting
Officer of any discrepancy, before performing any work.
3.2 INSTALLATION
Provide all chemicals, equipment and labor necessary to bring all system waters in conformance with the specified
requirements. Perform all work in accordance with the manufacturer's published diagrams, recommendations, and
equipment warranty requirements.
3.3 PIPING
Connections between dissimilar metals shall be made with a dielectric union.
3.4 TRAINING COURSE
Conduct a training course for the operating staff as designated by the Contracting Officer. The training period
shall consist of a total [_____] hours of normal working time and start after the system is functionally completed
but prior to final acceptance tests. The field instructions shall cover all of the items contained in the Operation
and Maintenance Manuals as well as demonstrations of routine maintenance operations.
3.5 TESTS
If the waters of the mechanical systems are not in conformance with the specified requirements or in accordance
with manufacturer's recommendations, the water treatment company shall take corrective action to enable compliance.
Daily operational tests shall be performed in the directed frequencies to maintain required control to prevent
corrosion, scaling and damage to equipment during operation
3.5.1 Condenser Water Quality Tests
3.5.1.1 Small Systems (weekly)
Once a week, for cooling systems with a capacity of 175.8 kW 50 tons or less, the following items shall be recorded.
PH [_____]
Total Alkalinity (as CaCO3) [_____] ppm (mg/L)
Conductivity [_____] micromho/cm
3.5.1.2 Tests for Large Systems (daily)
Daily, for cooling systems with a capacity larger than 175.8 kW 50 tons, the following items shall be recorded.
PH [_____]
Total Alkalinity (as CaCO3) [_____] ppm (mg/L)
Conductivity [_____] micromho/cm
Phosphonate [_____] ppm (mg/L)
Zinc, if used (Zn) [_____] ppm (mg/L)
Molybdate, if used (Mo) [_____] ppm (mg/L)
3.5.2 Chilled Water Testing (monthly)
Once a month, the following tests will be performed on chilled water.
PH [_____]
Nitrite or Molybdate [_____] ppm (mg/L)
Conductivity [_____] micromho/cm
3.5.3 Hot Water Boiler Water Quality Testing
3.5.3.1 Low and Medium Temperature Systems (monthly)
Monthly testing shall be completed and recorded for the following parameters.
PH [_____]
Nitrite or Molybdate [_____] ppm (mg/L)
3.5.3.2 High Temperature Hot Water Systems (daily)
Daily testing shall be completed and recorded for the following parameters.
PH [_____]
Sulfite (Na2SO3) [_____] ppm (mg/L)
Hardness [_____] ppm (mg/L)
3.5.4 Steam Boiler Water Testing
3.5.4.1 Small Steam Systems
The type of treatment required for small steam systems (below 0.25 MW 25 hp) varies greatly depending on local
water and system conditions. The type of treatment and frequency of testing shall be determined by the water
treatment chemical vendor.
3.5.4.2 Medium Steam Systems (twice weekly)
Twice a week for steam boiler systems operating between 0.25 MW 25 hp and 1 MW 100 hp the following items will
be recorded and utilized for operation purposes.
PH [_____]
P Alkalinity (as CaCO3) [_____] ppm (mg/L)
Total Dissolved Solids [_____] ppm (mg/L)
Phosphate (PO4) [_____] ppm (mg/L)
Sulfite (NaSO3) [_____] ppm (mg/L)
3.5.4.3 Large Steam Systems (daily)
Daily, for steam boiler systems operating above 100 kPa 15 psi and 1 MW 100 hp, the following items will be recorded
and utilized for operational purposes.
Sulfite (NaSO3) [_____] ppm (mg/L)
P Alkalinity (as CaCO3) [_____] ppm (mg/L)
Conductivity [_____] micromho/cm
Neutralized Conductivity [_____] micromho/cm
Total Dissolved Solids [_____] ppm (mg/L)
Phosphate (PO4) [_____] ppm (mg/L)
Condensate pH [_____]
Condensate Conductivity [_____] micromho/cm
Condensate Hardness (as CaCO3) [_____] ppm (mg/L)
Makeup Water Hardness (as CaCO3) [_____] ppm (mg/L)
3.5.5 Quality Assurance Testing
NOTE: It is important to require Quality Assurance (QA) testing performed
by an independent industrial water treatment laboratory/consultant to sustain
good water chemistry control. Systems without good chemistry control will experience
higher equipment replacement costs, energy and operating costs, higher water
usage, more plant shutdowns, higher and decreased safety.
Conduct quality assurance testing periodically by an independent water treatment lab/consultant to verify to
managers that the mechanical and water treatment systems are being maintained properly. Provide the Quality
Assurance evaluation reports to the government COR.
3.5.5.1 Condenser Water Quality Assurance Tests
a. For cooling systems with a capacity of 175.8 kW 50 ton or less, the following tests shall be performed
Presence of scale/corrosion [_____]
Polyphosphate [_____] ppm (mg/L)
Biocide [_____] ppm (mg/L)
PH [_____]
Total Alkalinity (as CaCO3) [_____] ppm (mg/L)
Calcium Hardness (as CaCO3) [_____] ppm (mg/L)
Conductivity [_____] micromho/cm
Written evaluation summary
b. For cooling systems with capacities greater than 175.8 kW 50 ton), the condenser water shall be analyzed
a minimum of once a month for a period of one year by the water treatment company. The analysis shall
include the following information recorded in accordance with ASTM D 596.
Date of Sample [_____]
Temperatures (before & after condenser) [_____] [_____] degrees C.
pH [_____]
Silica (SiO2) [_____] ppm (mg/L)
Iron (total, as Fe(2)O(3)) [_____] ppm (mg/L)
Copper (Cu) [_____] ppm (mg/L)
Calcium Hardness(CaCO3) [_____] ppm (mg/L)
Total Hardness (as CaCO3) [_____] ppm (mg/L)
Chloride (Cl) [_____] ppm (mg/L)
Total Alkalinity (as CaCO3) [_____] ppm (mg/L)
Conductivity [_____] micromho/cm
Total Dissolved Solids [_____] ppm (mg/L)
Phosphonate (as PO4) [_____] ppm (mg/L)
Zinc (if used) (Zn) [_____] ppm (mg/L)
Molybdate (if used) (Mo) [_____] ppm (mg/L)
Tolyltriazole (TT) [_____] ppm (mg/L)
Biocide [_____] ppm (mg/L)
Bacteria colony count [_____] colonies/mL
Makeup water pH [_____] ppm (mg/L)
Makeup water Iron [_____] ppm (mg/L)
Makeup water Silica [_____] ppm (mg/L)
Makeup water Calcium Hardness [_____] ppm (mg/L)
Makeup water Total Hardness [_____] ppm (mg/L)
Makeup water Total Alkalinity [_____] ppm (mg/L)
Makeup water Chloride (Cl) [_____] ppm (mg/L)
Makeup water Conductivity [_____] micromho/cm
Written evaluation summary
3.5.5.2 Chilled Water Quality Assurance Testing (quarterly)
Quarterly, the following tests shall be performed on chilled water.
PH [_____]
Nitrite or Molybdate [_____] ppm (mg/L)
Conductivity [_____] micromho/cm
Iron (total, as Fe(2)O(3)) [_____] ppm (mg/L)
Written evaluation summary
3.5.5.3 Hot Water Boiler Water Quality Assurance Testing
a. Quarterly testing of Low and Medium Temperature Systems shall be completed and recorded for the following
parameters.
PH [_____]
Nitrite or Molybdate [_____] ppm (mg/L)
Iron (total, as Fe(2)O(3)) [_____] ppm (mg/L)
Written evaluation summary
b. The hot water boiler water shall be analyzed once a month for a period of 1 year by an independent
consultant. The analysis shall include the following information recorded in accordance with ASTM D 596
.
PH [_____]
Sulfite (Na2SO3) [_____] ppm (mg/L)
Hardness(as CaCO3) [_____] ppm (mg/L)
Iron (total, as Fe(2)O(3)) [_____] ppm (mg/L)
Written evaluation summary
3.5.5.4 Steam Boiler Water Quality Assurance Tests
a. Small and Medium Steam Boiler Systems (quarterly)are systems operating between 0.25 MW 25 hp and
1 MW 100 hp. The following tests shall be performed quarterly.
pH [_____]
Sulfite, if used, (NaSO3) [_____] ppm (mg/L)
P Alkalinity (as CaCO3) [_____] ppm (mg/L)
Total Dissolved Solids [_____] ppm (mg/L)
Phosphate, if used, (PO4) [_____] ppm (mg/L)
Polymer, if used [_____] ppm (mg/L)
Iron (total, as Fe(2)O(3)) [_____] ppm (mg/L)
Condensate pH [_____]
Condensate Conductivity [_____] micromho/cm
Condensate Hardness (as CaCO3) [_____] ppm (mg/L)
Condensate Iron (total, as Fe(2)O(3)) [_____] ppm (mg/L)
Makeup Water Hardness (as CaCO3) [_____] ppm (mg/L)
Written evaluation summary
b. Large steam boilers are those operating above 100 kPa 15 psi and 1 MW 100 hp. The boiler water shall
be analyzed a minimum of once a month for a period of 1 year by an independent consultant. The analysis
shall include the following information recorded in accordance with ASTM D 596.
Date of Sample [_____]
pH [_____]
Sulfite (NaSO3) [_____] ppm (mg/L)
P Alkalinity (as CaCO3) [_____] ppm (mg/L)
Conductivity [_____] micromho/cm
Neutralized Conductivity [_____] micromho/cm
Total Dissolved Solids [_____] ppm (mg/L)
Phosphate (PO4) [_____] ppm (mg/L)
Polymer [_____] ppm (mg/L)
Silica (SiO2) [_____] ppm (mg/L)
Iron (total, as Fe(2)O(3)) [_____] ppm (mg/L)
Condensate pH [_____]
Condensate Conductivity [_____] micromho/cm
Condensate Hardness (as CaCO3) [_____] ppm (mg/L)
Condensate Iron (total, as Fe(2)O(3)) [_____] ppm (mg/L)
Makeup Water Hardness (as CaCO3) [_____] ppm (mg/L)
Written evaluation summary
3.5.6 Corrosion Testers
NOTE: Choose from the systems below to be monitored with corrosion testers.
Install corrosion coupon and rack systems to verify corrosion control in the systems. Testers or coupons are
installed in flowing system water through a sidestream or rack system. Both mild steel and copper metal samples
are to be tested in the corrosion testers in accordance with ASTM D 2688. Samples are to be replaced and analyzed
every 3 months. Rates of corrosion less than 3 mpy for steel and 0.2 mpy for copper are acceptable. Corrosion
testers shall be installed on the piping systems of the following systems.
Condenser loop
Chilled water system
Hot water loop
Condensate
3.6 INSPECTIONS
3.6.1 Inspection General Requirements
Thirty days after project completion, inspect the cooling tower and condenser for problems due to corrosion,
scale, and biological growth. If the cooling tower and condenser are found not to conform to the manufacturer's
recommended conditions, and the water treatment company recommendations have been followed; the water treatment
company shall provide all chemicals and labor for cleaning or repairing the equipment as required by the manufacturer's
recommendations.
3.6.2 Boiler/Piping Test
NOTE: If a steam boiler is not used, delete the reference to condensate piping.
Thirty day after project completion, inspect the boiler and condensate piping for problems due to corrosion and
scale. If the boiler is found not to conform to the manufacturer's recommendations, and the water treatment
company recommendations have been followed, the water treatment company shall provide all chemicals and labor
for cleaning or repairing the equipment as required by the manufacturer's recommendations. If corrosion is found
within the condensate piping, proper repairs shall be made by the water treatment company.