USACE / NAVFAC / AFCESA / NASA UFGS-40 17 26.00 20 (April 2006)
------------------------------
Preparing Activity: NAVFAC Replacing without change
UFGS-15216N (September 1999)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 40 17 26.00 20
WELDING PRESSURE PIPING
04/06
NOTE: This guide specification covers the requirements for welding of piping
and piping system components which will contain fluids under pressure including
hydraulic 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).
NOTE: Piping materials, components, and supports are specified in other sections
of the project specifications.
NOTE: The following information shall be shown on the project drawings:
1. Tensile strength, elongation, shear strength, size, length, type, and location
of the welds, as necessary.
2. The project drawings should be checked to ensure that any supplementary
information required by the paragraphs has been shown and that there is no conflict
between the drawings and the specifications. See also Note in paragraph entitled
"Definitions." The project drawings must indicate, or text of the project specifications
must specify, the tensile strength, elongation, shear strength, size, length,
type, and location of the welds, as necessary.
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.
[AMERICAN PETROLEUM INSTITUTE (API)API Std 1104(2005; Errata 2007; Errata 2008) Welding of Pipeline and Related Facilities][AMERICAN SOCIETY FOR NONDESTRUCTIVE TESTING (ASNT)ASNT RP SNT-TC-1A(2006) Recommended Practice][AMERICAN WELDING SOCIETY (AWS)AWS A2.4(2007) Standard Symbols for Welding, Brazing and Nondestructive ExaminationAWS A3.0(2001) Standard Welding Terms and Definitions Including Terms for Adhesive Bonding, Brazing, Soldering, Thermal Cutting and Thermal SprayingAWS B2.1(2005; Errata 2006; Errata 2006) Welding Procedure and Performance QualificationAWS D1.1/D1.1M(2008) Structural Welding Code - SteelAWS QC1(2007) AWS Certification of Welding InspectorsAWS Z49.1(2005) Safety in Welding, Cutting and Allied Processes][ASME INTERNATIONAL (ASME)ASME B31.1(2007; Addenda 2008) Power PipingASME B31.3(2008) Process PipingASME B31.4(2006) Pipeline Transportation Systems for Liquid Hydrocarbons and Other LiquidASME B31.5(2006) Refrigeration Piping and Heat Transfer ComponentsASME B31.9(2008) Building Services PipingASME BPVC SEC I(2007; Addenda 2008) Boiler and Pressure Vessel Code; Section I, Power BoilersASME 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 IX(2007; Addenda 2008) Boiler and Pressure Vessel Code; Section IX, Welding and Brazing QualificationsASME BPVC SEC V(2007; Addenda 2008) Boiler and Pressure Vessel Code; Section V, Nondestructive Examination][U.S. NATIONAL ARCHIVES AND RECORDS ADMINISTRATION (NARA)29 CFR 1910Occupational Safety and Health Standards29 CFR 1926Safety and Health Regulations for Construction]1.2 RELATED REQUIREMENTS
NOTE: The project drawings should be checked to ensure that any supplementary
information required by the paragraphs has been shown and that there is no conflict
between the drawings and the specifications.
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: Insert the applicable ANSI piping codes. ANSI B31.2, "Fuel Gas Piping,"
and ASME B31.8, "Gas Transmission and Distribution Piping Systems," not listed
under paragraph entitled "References," may be used.
AWS A3.0 [and applicable ANSI piping documents].
1.4 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
Welding pressure piping
SD-07 Certificates
Welding procedures qualification
Nondestructive examination (NDE) procedures
NDE personnel certification procedures
Inspector certification
Submit inspector certification and NDE personnel certification for record.
SD-11 Closeout Submittals
Weld identifications
1.5 QUALITY ASSURANCE
1.5.1 Welding Pressure Piping
Show location, length, and type of welds, and indicate postweld heat treatment and nondestructive testing as
required.
1.5.2 Procedures
NOTE: Insert the applicable ANSI piping codes. ANSI B31.2, "Fuel Gas Piping,"
and ASME B31.8, "Gas Transmission and Distribution Piping Systems," not listed
under paragraph entitled "References," may be used.
Develop and qualify procedures for welding metals included in the work. Do not start welding until welding procedures,
welders, and welding operators have been qualified. Perform qualification testing by an approved testing laboratory,
or by the Contractor if approved by the Contracting Officer in accordance with the qualified procedures. Notify
the Contracting Officer at least 24 hours in advance of the time and place of the tests. When practicable, perform
the qualification tests at or near the work site. Maintain current records of the test results obtained in welding
procedure, welding operator/welder performance qualifications, and nondestructive examination (NDE) procedures
. These records shall be readily available at the site for examination by the Contracting Officer.Qualify the
procedures for making transition welds between different materials or between plates or pipes of different wall
thicknesses. [ANSI Piping] [_____] requirements for branch connections may be used in lieu of detailed designs.
Unless otherwise specified, the choice of welding process shall be the responsibility of the Contractor.
1.5.2.1 Previous Qualifications
Welding procedures, welders, and welding operators previously qualified by test may be accepted for the work
without requalification provided that the following conditions are fulfilled:
a. Copies of welding procedures, procedure qualification test records, and welder and welding
operator performance qualification test records are submitted and approved in accordance with
the paragraph entitled "Submittals."
b. Testing was performed by an approved testing laboratory or technical consultant or by the
Contractor's approved quality control organization.
c. The welding procedures, welders, and welding operators were qualified in accordance with
ASME BPVC SEC IX or AWS B2.1, AR-2 level; and base materials, filler materials, electrodes,
equipment, and processes conformed to the applicable requirements of this specification.
d. The requirements of paragraph entitled "Welder and Welding Operator Performance Qualification"
for renewal of qualification were met, and records showing name of employer and period of employment
using the process for which qualified are submitted as evidence of conformance.
1.5.2.2 Performance
NOTE: The paragraphs will be edited and inserted if necessary to ensure proper
implementation of the "CONTRACTOR QUALITY CONTROL PROGRAM." The specification
writer or design engineer must indicate how much quality control of welding
is needed for each project and who is to be responsible, i.e., primarily the
Contractor or the Government. If quality control is to be the responsibility
of the Government, delete paragraphs entitled "Performance" and "Qualification
of Inspection and Nondestructive Examination (NDE) Personnel" through "NDE Personnel
Qualification" and renumber paragraphs as necessary. Rarely will a project
require 100 percent testing of welds by NDE methods. The designer must determine
the required methods and the extent of inspection and testing and must indicate
the extent in this or other sections of the project specifications or on the
project drawings by notes, nondestructive test symbols, or other means. The
referenced applicable publications and Army Technical Manual, "Welding Design,
Procedures and Inspection," TM-5-805-7, will be used for guidance in determining
inspection and testing requirements. The specifications or project drawings
must clearly indicate which joints require 100 percent NDE inspection, which
joints require random NDE inspection, and which NDE methods are to be employed
for each joint. For random inspection, the project drawings must indicate the
location, number of joints, and minimum increment length of weld that will be
subject to NDE inspection without predisclosing the exact spots to be examined.
Joints not indicated to be tested by NDE methods shall be subject to visual
inspection only. In cases where the nature of the welding is such as to require
visual inspection only, the requirements for nondestructive examinations should
be deleted from these paragraphs and from paragraph entitled "Qualification
of Inspection and Nondestructive Examination (NDE) Personnel."
The Contractor shall be responsible for the quality of joint preparation, welding, and examination. Clearly
identify and record materials used in the welding operations. The examination and testing defined in this specification
are minimum requirements. Provide additional examination and testing as necessary to achieve the quality required.
1.5.3 Welding Procedures Qualification
NOTE: The project drawings must indicate, or text of the project specifications
must specify, the tensile strength, elongation, shear strength, size, length,
type, and location of the welds, as necessary.
NOTE: Insert the applicable ANSI piping codes. ANSI B31.2, "Fuel Gas Piping,"
and ASME B31.8, "Gas Transmission and Distribution Piping Systems," not listed
under paragraph entitled "References," may be used.
Qualification of the welding procedures for each group of materials to be welded is required as indicated in
ASME BPVC SEC IX. Record in detail and qualify the "Welding Procedure Specifications" for every welding procedure
proposed. Qualification for each welding procedure shall conform to the requirements of ANSI Standards and to
this specification. The welding procedures shall specify end preparation for welds, including cleaning, alignments,
and root openings. Preheat, interpass temperature control, and postheat treatment of welds shall be as required
by ANSI Piping documents, unless otherwise indicated or specified. Describe the type of backing rings or consumable
inserts, if used, and, if they are to be removed, the removal process. Welding procedure qualifications shall
be identified individually and referenced on the shop drawings or suitably keyed to the contract drawings.
1.5.4 Welder and Welding Operator Performance Qualification
NOTE: Insert the applicable ANSI piping codes. ANSI B31.2, "Fuel Gas Piping,"
and ASME B31.8, "Gas Transmission and Distribution Piping Systems," not listed
under paragraph entitled "References," may be used.
Qualify each welder and welding operator assigned to work covered by this specification by performance tests
using equipment, positions, procedures, base metals, and electrodes or bare filler wires from the same specification,
classification, or group number that will be encountered on his assignment. Welders or welding operators who
make acceptable procedure qualification tests will be considered performance-qualified for the welding procedure
used. Determine performance qualification in accordance with [ASME BPVC SEC IX, [ANSI Piping Standards]] [_____]
and as specified.
1.5.5 Renewal of Qualification
Requalification of a welder or welding operator shall be required under one or any combination of the following
conditions:
a. When a welder or welding operator has not used the specific welding process for a period
of 3 months. The period may be extended to 6 months if the welder has been employed on another
welding process.
b. There is specific reason to question the welder's ability to make welds that will meet the
requirements of the specifications.
c. The welder or welding operator was qualified by an employer other than those firms performing
work under this contract and a qualification test has not been taken within the preceding 12
months. Renewal of qualification under this condition need be made on only a single test joint
or pipe of any thickness, position, or material to reestablish qualification for any thickness,
position, or material for which the welder or welding operator had qualified previously.
1.5.6 Qualification of Inspection and (NDE) Personnel
Qualification of Inspection and Nondestructive Examination (NDE) Personnel: Qualify inspection and nondestructive
examination personnel in accordance with the following requirements:
1.5.6.1 Inspector Certification
Qualify welding inspectors in accordance with AWS QC1.
1.5.6.2 NDE Personnel Certification Procedures
NOTE: The paragraphs will be edited and inserted if necessary to ensure proper
implementation of the "CONTRACTOR QUALITY CONTROL PROGRAM." The specification
writer or design engineer must indicate how much quality control of welding
is needed for each project and who is to be responsible, i.e., primarily the
Contractor or the Government. If quality control is to be the responsibility
of the Government, delete paragraphs entitled "Performance" and "Qualification
of Inspection and Nondestructive Examination (NDE) Personnel" through "NDE Personnel
Qualification" and renumber paragraphs as necessary. Rarely will a project
require 100 percent testing of welds by NDE methods. The designer must determine
the required methods and the extent of inspection and testing and must indicate
the extent in this or other sections of the project specifications or on the
project drawings by notes, nondestructive test symbols, or other means. The
referenced applicable publications and Army Technical Manual, "Welding Design,
Procedures and Inspection," TM-5-805-7, will be used for guidance in determining
inspection and testing requirements. The specifications or project drawings
must clearly indicate which joints require 100 percent NDE inspection, which
joints require random NDE inspection, and which NDE methods are to be employed
for each joint. For random inspection, the project drawings must indicate the
location, number of joints, and minimum increment length of weld that will be
subject to NDE inspection without predisclosing the exact spots to be examined.
Joints not indicated to be tested by NDE methods shall be subject to visual
inspection only. In cases where the nature of the welding is such as to require
visual inspection only, the requirements for nondestructive examinations should
be deleted from these paragraphs and from paragraph entitled "Qualification
of Inspection and Nondestructive Examination (NDE) Personnel."
Certify NDE personnel and establish a written procedure for the control and administration of NDE personnel training,
examination, and certification. Base procedures on appropriate specific and general guidelines of training and
experience recommended by ASNT RP SNT-TC-1A, [Supplement A-Radiographic] [Supplement B-Magnetic particle] [Supplement
C-Ultrasonic] [and] [Supplement D-Liquid Penetrant].
1.5.6.3 Welding Procedures and Qualifications
a. Specifications and Test Results: Submit copies of the welding procedure specifications
and procedure qualification test results for each type of welding required. Approval of any
procedure does not relieve the Contractor of the responsibility for producing acceptable welds.
Submit this information on the forms printed in ASME BPVC SEC IX or their equivalent.
b. Certification: Before assigning welders or welding operators to the work, submit their
names, together with certification that each individual is performance qualified as specified.
Do not start welding work prior to procedure qualification. The certification shall state the
type of welding and positions for which each is qualified, the code and procedure under which
each is qualified, date qualified, and the firm and individual certifying the qualification
tests.
1.5.7 Symbols
Conform to AWS A2.4.
1.5.7.1 Weld Identifications
Submit a list of the welders' names and symbol for each welder. To identify welds, submit written records indicating
the location of welds made by each welder or welding operator.
1.5.8 Safety
Conform to AWS Z49.1, 29 CFR 1910-SUBPART Q, "Welding, Cutting, and Brazing," 29 CFR 1926-SUBPART J, "Welding
and Cutting."
1.6 ENVIRONMENTAL
Do not perform welding when the quality of the completed weld could be impaired by the prevailing working or
weather conditions. The Contracting Officer will determine when weather or working conditions are unsuitable
for welding.
1.7 DELIVERY AND STORAGE
Deliver filler metals, electrodes, fluxes and other welding materials to the site in manufacturers' original
packages and store in a dry space until used. Label and design packages properly to give maximum protection
from moisture and to assure safe handling.
PART 2 PRODUCTS
2.1 WELDING MATERIALS
NOTE: Normally, selection of the electrodes is done by the Contractor as part
of his qualified welding procedure. In special cases, if the selection of the
proper electrode is critical to the design, the designer may specify the electrodes
to be used. In special cases it also may be necessary to specify the welding
process.
Comply with 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.
PART 3 EXECUTION
3.1 WELDING
Do not deviate from applicable codes, approved procedures and approved shop drawings without prior written approval
from the Contracting Officer. Materials or components with welds made off the site will not be accepted if the
welding does not conform to the requirements of this specification unless otherwise specified. Assign each welder
or welding operator an identifying number, letter, or symbol that shall be used to identify his welds. Each
welder or welding operator shall apply his mark adjacent to his weld using an approved rubber stamp or felt-tipped
marker with permanent, weatherproof ink or other approved methods that do not deform the metal. For seam welds,
place identification marks adjacent to the welds at one meter 3 foot intervals. Confine identification by die
stamps or electric etchers to the weld reinforcing crown, preferably in the finished crater.
3.2 WELDING OPERATORS
Perform welding in accordance with qualified procedures using qualified welders and welding operators.
3.3 SUPPORTS
Welding of hangers, supports, and plates to structural members shall conform to AWS D1.1/D1.1M.
3.4 EXAMINATIONS AND TESTS
NOTE: The paragraphs will be edited and inserted if necessary to ensure proper
implementation of the "CONTRACTOR QUALITY CONTROL PROGRAM." The specification
writer or design engineer must indicate how much quality control of welding
is needed for each project and who is to be responsible, i.e., primarily the
Contractor or the Government. If quality control is to be the responsibility
of the Government, delete paragraphs entitled "Performance" and "Qualification
of Inspection and Nondestructive Examination (NDE) Personnel" through "NDE Personnel
Qualification" and renumber paragraphs as necessary. Rarely will a project
require 100 percent testing of welds by NDE methods. The designer must determine
the required methods and the extent of inspection and testing and must indicate
the extent in this or other sections of the project specifications or on the
project drawings by notes, nondestructive test symbols, or other means. The
referenced applicable publications and Army Technical Manual, "Welding Design,
Procedures and Inspection," TM-5-805-7, will be used for guidance in determining
inspection and testing requirements. The specifications or project drawings
must clearly indicate which joints require 100 percent NDE inspection, which
joints require random NDE inspection, and which NDE methods are to be employed
for each joint. For random inspection, the project drawings must indicate the
location, number of joints, and minimum increment length of weld that will be
subject to NDE inspection without predisclosing the exact spots to be examined.
Joints not indicated to be tested by NDE methods shall be subject to visual
inspection only. In cases where the nature of the welding is such as to require
visual inspection only, the requirements for nondestructive examinations should
be deleted from these paragraphs and from paragraph entitled "Qualification
of Inspection and Nondestructive Examination (NDE) Personnel."
NOTE: Information based on the two tables must be developed and included in
each project specification. Tables must clearly define the systems to be inspected
and the type of NDE required. Specify 100 percent NDE when required by DM-22
and 49 CFR 195, as covered by paragraph entitled "Piping Subject to 100 percent
NDE."
Visual and nondestructive examinations shall be performed [by the Government] [by the Contractor] to detect surface
and internal discontinuities in completed welds. [Employ the services of a qualified commercial inspection or
testing laboratory or technical consultant approved by the Contracting Officer.] Visually examine welds [Radiographic,]
[Liquid penetrant,] [Magnetic particle,] [or] [Ultrasonic] examination shall be required as indicated in Tables
[IV] [and] [V] attached to this section [or in accordance with other sections where detailed requirements are
specified]. Random NDE testing applies to ASME B31.3 and ASME B31.4 piping unless specified otherwise. When
examination and testing indicates defects in a weld joint, a qualified welder shall repair the weld in accordance
with the paragraph entitled "Corrections and Repairs" of this section.
3.4.1 Random NDE Testing
NOTE: The paragraphs will be edited and inserted if necessary to ensure proper
implementation of the "CONTRACTOR QUALITY CONTROL PROGRAM." The specification
writer or design engineer must indicate how much quality control of welding
is needed for each project and who is to be responsible, i.e., primarily the
Contractor or the Government. If quality control is to be the responsibility
of the Government, delete paragraphs entitled "Performance" and "Qualification
of Inspection and Nondestructive Examination (NDE) Personnel" through "NDE Personnel
Qualification" and renumber paragraphs as necessary. Rarely will a project
require 100 percent testing of welds by NDE methods. The designer must determine
the required methods and the extent of inspection and testing and must indicate
the extent in this or other sections of the project specifications or on the
project drawings by notes, nondestructive test symbols, or other means. The
referenced applicable publications and Army Technical Manual, "Welding Design,
Procedures and Inspection," TM-5-805-7, will be used for guidance in determining
inspection and testing requirements. The specifications or project drawings
must clearly indicate which joints require 100 percent NDE inspection, which
joints require random NDE inspection, and which NDE methods are to be employed
for each joint. For random inspection, the project drawings must indicate the
location, number of joints, and minimum increment length of weld that will be
subject to NDE inspection without predisclosing the exact spots to be examined.
Joints not indicated to be tested by NDE methods shall be subject to visual
inspection only. In cases where the nature of the welding is such as to require
visual inspection only, the requirements for nondestructive examinations should
be deleted from these paragraphs and from paragraph entitled "Qualification
of Inspection and Nondestructive Examination (NDE) Personnel."
NOTE: This paragraph will be deleted when the Contractor is not required to
perform random inspection. Edit to delete any listed nondestructive test method
which is inapplicable. Insert a number from 1 to 99 for percent of welds to
be randomly inspected; 10 percent is recommended for most projects.
When [radiographic,] [liquid penetrant,] [magnetic particle,] [or] [ultrasonic] examination is required, test
a minimum of [10] [_____] percent of the total length or number of piping welds. Randomly select the welds examined,
but include an examination of welds made by each welding operator or welder. If random testing reveals that
a weld fails to meet minimum quality requirements, examine an additional [10] [_____] percent of the welds in
that same group. If the additional welds examined meet the quality requirements, the entire group of welds represented
shall be accepted and the defective welds shall be repaired. If any of the additional welds examined also fail
to meet the quality requirements, that entire group of welds shall be rejected. Remove and reweld rejected welds
or examine rejected welds 100 percent and remove and reweld defects.
3.4.2 Visual Examination
Visually examine welds as follows:
a. Before welding -- for compliance with requirements for joint preparation, placement of backing
rings or consumable inserts, alinement and fit-up, and cleanliness.
b. During welding -- for conformance to the qualified welding procedure.
c. After welding -- for cracks, contour and finish, bead reinforcement, undercutting, overlap,
and size of fillet welds.
3.4.3 Nondestructive Examination
NOTE: Delete any nondestructive test method not required. If magnetic particle
inspection is required, specify whether wet or dry particle method is appropriate.
NDE shall be in accordance with written procedures. Procedures for [radiographic,] [liquid penetrant,] [magnetic
particle,] [or] [ultrasonic] tests and methods shall conform to ASME BPVC SEC V. The approved procedure shall
be demonstrated to the satisfaction of the Contracting Officer's QA personnel. In addition to the information
required in ASME BPVC SEC V, the written procedures shall include:
a. Timing of the nondestructive examination in relation to the welding operations.
b. Safety precautions.
3.4.4 Examinations and Tests by the Government
Examinations and tests will conform to paragraphs "Visual Examination" and "Nondestructive Examination" of this
section, except that destructive tests may be required also. When destructive tests are made, qualified welders
or welding operators shall make repairs using welding procedures which will develop the full strength of the
members cut. Welding shall be subject to examination and tests in the mill, shop, and field.
3.4.5 Piping Subject to 100 Percent NDE
ASME B31.4 [and ASME B31.3] Piping Subject to 100 Percent NDE: 100 percent of each day's girth welds installed
in the following locations shall be nondestructively examined 100 percent by radiographic, magnetic particle,
or liquid penetrant examination unless impracticable, in which case at least 90 percent must be examined. Nondestructive
examination must be impracticable for each girth weld not examined.
a. At onshore locations where a loss of hazardous liquid (petroleum, petroleum products, or
anhydrous ammonia) could reasonably be expected to pollute stream, river, lake, reservoir, or
other body of water, and any offshore area;
b. Within railroad or public road rights-of-way;
c. At overhead road crossings and within tunnels;
d. Within the limits of any incorporated subdivision of a State government; and
e. Within populated areas, including, but not limited to, residential subdivisions, shopping
centers, schools, designated commercial areas, industrial facilities, public institutions, and
places of public assembly.
3.5 ACCEPTANCE STANDARDS
NOTE: These acceptance standards are taken from ASME B31.1 and are suitable
for most jobs. Evaluations of indications as given in ASME B31.1 are applicable
to these standards. Visual acceptance standards are given for some other piping
codes. It should be noted that specific project design requirements may necessitate
revision or expansion to cover different items of work and varying standards
of acceptance.
3.5.1 Visual
The following indications are unacceptable:
a. Cracks--external surface.
NOTE: In the text below, if only ASME B31.3 is applicable, delete all text
in brackets. For ASME B31.3 under normal service conditions, use 25 percent
with text in brackets and omit last sentence in brackets. For ASME B31.4 use
12.5 percent, and add the material in brackets pertaining to B31.4. Consider
use of ASME B31.1 acceptance standard for codes other than B31.3 and B31.4.
b. Undercut on surface which is greater than 1.00 mm 1/32 inchdeep [or [25 percent for ASME B31.3
] [and] [12.5 percent for ASME B31.4 and ASME B31.9] of the wall thickness, whichever is less,]
provided that the remaining wall thickness is not less than the minimum design thickness. [For
ASME B31.4 and in accordance with API Std 1104, undercuts over 0.40 mm through 0.80 mm 1/64
inch through 1/32 inch or over 6 to 12.5 percent of the pipe wall thickness, whichever is smaller,
shall not exceed 51 mm 2 inches in a continuous weld length of 305 mm 12 inches or 1/6 the length
of the weld, whichever is smaller; and undercuts 0.40 mm 1/64 inch or 6 percent of the wall
thickness, whichever is smaller, are acceptable regardless of length.]
NOTE: Include Tables I, II, or III below as applicable to project.
c. Weld reinforcement:
(1) ASME B31.1, conform to Table I.
TABLE I
REINFORCEMENT OF GIRTH AND LONGITUDINAL BUTT WELDS
____________________________________________________________________________
Maximum Thickness of Reinforcement
for Design Temperature
_________________________________________
Greater than Less Than
400oC 175oC-400oC 175oC
Thickness of Base Metal, _________ _______________ ________
millimeters (mm) mm mm mm
____________________________________________________________________________
Up to 3.00, incl. 2.00 2.50 5.00
Over 3.00 to 5.00, incl. 2.00 3.00 5.00
Over 5.00 to 13.00, incl. 2.00 4.00 5.00
Over 13.00 to 25.00, incl. 2.50 5.00 5.00
Over 25.00 to 50.00, incl. 3.00 6.00 6.00
Over 50.00 4.00 The greater of 6 mm
or 1/8 times the
width of the weld in
mm.
NOTES:
1. For double welded butt joints, this limitation on reinforcement given above shall apply separately to both
inside and outside surfaces of the joint.
2. For single welded butt joints, the reinforcement limits given above shall apply to the outside surface of the
joint only.
3. The thickness of weld reinforcement shall be based on the thickness of the thinner of the materials being joined.
4. The weld reinforcement thicknesses shall be determined from the higher of the abutting surfaces involved.
5. Weld reinforcement may be removed if so desired.
__________________________________________________________________________
TABLE I
REINFORCEMENT OF GIRTH AND LONGITUDINAL BUTT WELDS
____________________________________________________________________________
Maximum Thickness of Reinforcement
for Design Temperature
_________________________________________
Greater than Less Than
750oF 350oF-750oF 350oF
Thickness of Base Metal, _________ ___________ _______
inches inch inch inch
____________________________________________________________________________
Up to 1/8, incl. 1/16 3/32 3/16
Over 1/8 to 3/16, incl. 1/16 1/8 3/16
Over 3/16 to 1/2, incl. 1/16 5/32 3/16
Over 1/2 to 1, incl. 3/32 3/16 3/16
Over 1 to 2, incl. 1/8 1/4 1/4
Over 2 5/32 The greater of 1/4
in. or 1/8 times the
width of the weld in
inches.
NOTES:
1. For double welded butt joints, this limitation on reinforcement given above shall apply separately to both
inside and outside surfaces of the joint.
2. For single welded butt joints, the reinforcement limits given above shall apply to the outside surface of the
joint only.
3. The thickness of weld reinforcement shall be based on the thickness of the thinner of the materials being joined.
4. The weld reinforcement thicknesses shall be determined from the higher of the abutting surfaces involved.
5. Weld reinforcement may be removed if so desired.
___________________________________________________________________________
(2) ASME B31.3, conform to Table II.
TABLE II
_________________________________________________________________________
Wall Thickness, mm Height, mm
_________________________________________________________________________
Less than or equal to 6.40 Less than or equal to 1.60
Greater than 6.40, is less Less than or equal to 3.20
than or equal to 12.70
Greater than 12.70, is less Less than or equal to 4.00
than or equal to 25.40
Greater than 25.40 Less than or equal to 4.80
NOTES:
1. Wall thickness is the nominal wall thickness of the thinner of components joined by butt weld.
2. Height: For "Normal Service" and "Severe Cyclic" conditions, use thelisted value. For "Category D Fluid Service,"
use twice the listed value. Measure from surfaces of adjacent components. The lesser of the two measurements, in
any plane through the weld, shall not exceed the applicable value at right. Weld metal shall merge smoothly into
component surfaces.
__________________________________________________________________________
TABLE II
_________________________________________________________________________
Wall Thickness, Inches Height, Inches
_________________________________________________________________________
Less than or equal to 1/4 Less than or equal to 1/16
Greater than 1/4, is less Less than or equal to 1/8
than or equal to 1/2
Greater than 1/2, is less Less than or equal to 5/32
than or equal to 1
Greater than 1 Less than or equal to 3/16
NOTES:
1. Wall thickness is the nominal wall thickness of the thinner of
components joined by butt weld.
2. Height: For "Normal Service" and "Severe Cyclic" conditions, use the listed value. For "Category D Fluid
Service," use twice the listed value. Measure from surfaces of adjacent components. The lesser of the two measurements,
in any plane through the weld, shall not exceed the applicable value at right. Weld metal shall merge smoothly into
component surfaces.
__________________________________________________________________________
(3) ASME B31.4, conform to Table I for under 175 degrees C 350 degrees F.
(4) ASME B31.5, conform to Table III.
TABLE III
__________________________________________________________________________
Pipe Wall Thickness, mm Reinforcement Thickness, mm
__________________________________________________________________________
6.40 and under 1.60
Over 6.40 through 12.70 2.40
Over 12.70, through 25.40 3.20
Over 25.40 4.80
___________________________________________________________________________
TABLE III
___________________________________________________________________________
Pipe Wall Thickness, inches Reinforcement Thickness, inches
___________________________________________________________________________
1/4 and under 1/16
Over 1/4 through 1/2 3/32
Over 1/2, through 1 1/8
Over 1 3/16
___________________________________________________________________________
(5) ASME B31.9: Thickness of weld reinforcement shall not exceed 4.80 mm 3/16 inch.
d. Lack of fusion on surface.
e. Incomplete penetration (applies only when inside surface is readily accessible).
f. Convexity of fillet weld surface greater than 10 percent of longest leg plus 1.0 mm 0.03
inch.
g. Concavity in groove welds.
h. Concavity in fillet welds greater than 2.0 mm 1/16 inch.
i. Fillet weld size less than indicated or greater than 1 1/4 times the minimum specified fillet
leg length.
3.5.2 Magnetic Particle Examination
The following relevant indications are unacceptable:
a. Any cracks and linear indications.
b. Rounded indications with dimensions greater than 5.0 mm 3/16 inch.
c. Four or more rounded indications in a line separated by 2.0 mm 1/16 inch or less edge-to-edge.
d. Ten or more rounded indications in any 3870 sq. mm 6 square inches of surface, with the
major dimension of this area not to exceed 150 mm 6 inches, with the area taken in the most
unfavorable location relative to the indications being evaluated.
3.5.3 Liquid Penetrant Examination
Indications whose major dimensions are greater than 2.0 mm 1/16 inch shall be considered relevant. The following
relevant indications are unacceptable:
a. Any cracks or linear indications.
b. Rounded indications with dimensions greater than 5.0 mm 3/16 inch.
c. Four or more rounded indications in a line separated by 2.0 mm 1/16 inch or less edge-to-edge.
d. Ten or more rounded indications in any 3870 sq. mm 6 square inches of surface, with the
major dimension of this area not to exceed 150 mm 6 inches, with the area taken in the most
unfavorable location relative to the indications being evaluated.
3.5.4 Radiography
Welds that are shown by radiography to have any of the following discontinuities are unacceptable:
a. Any type of crack or zone of incomplete fusion or penetration.
b. Any other elongated indication which has a length greater than:
(1) 6.0 mm 1/4 inch for t up to 19.0 mm 3/4 inch, inclusive;
(2) 1/3 t for t from 19.0 mm 3/4 inch to 57.00 mm 2 1/4 inches, inclusive;
(3) 19.00 mm 3/4 inch for t over 57.00 mm 2 1/4 inches where t is the thickness of the thinner
portion of the weld.
("t" pertains to the thickness of the weld being examined. If a weld joins two members having different thickness
at the weld, "t" is the thinner of these two thicknesses.)
c. Any group of indications in line that have an aggregate length greater than t in a length
of 12t, except where the distance between the successive indications exceeds 6L where L is the
longest indication in the group.
d. Porosity in excess of that shown acceptable in Appendix A-250, Acceptance Standard for Radiographically
Determined Rounded Indications in Welds, ASME BPVC SEC I.
3.5.5 Ultrasonic Examination
Permitted for ASME B31.3 and ASME B31.4 piping only. Linear type discontinuities are unacceptable if the amplitude
exceeds the reference level and discontinuities have lengths which exceed the following:
a. 6.0 mm 1/4 inch for t up to 19.0 mm 3/4 inch
b. 1/3 t for t from 19.0 mm 3/4 inch to 57.0 mm 2 1/4 inches
c. 19.0 mm 3/4 inch for t over 57.0 mm 2 1/4 inches
("t" is the thickness of the weld being examined. If the weld joins two members having different thickness at
the weld, "t" is the thinner of these two thicknesses. Discontinuities are interpreted to be cracks, lack of
fusion, and incomplete penetration are unacceptable regardless of length.)
3.6 CORRECTIONS AND REPAIRS
NOTE: Insert the applicable ANSI piping codes. ANSI B31.2, "Fuel Gas Piping,"
and ASME B31.8, "Gas Transmission and Distribution Piping Systems," not listed
under paragraph entitled "References," may be used.
Remove defects and replace welds as specified in [ANSI Piping Standards] [_____], unless otherwise specified.
Repair defects discovered between weld passes before additional weld material is deposited. Wherever a defect
is removed, and repair by welding is not required, the affected area shall be blended into the surrounding surface
eliminating sharp notches, crevices, or corners. After defect removal is complete and before rewelding, reexamine
the area by the same test methods which first revealed the defect to ensure that the defect has been eliminated.
After rewelding, reexamine the repaired area by the same test methods originally used for that area. For repairs
to base material, the minimum examination shall be the same as required for butt welds. Indication of a defect
shall be regarded as a defect unless reevaluation by NDE or by surface conditioning shows that no unacceptable
indications are present. The use of foreign material to mask, fill in, seal, or disguise welding defects will
not be permitted.
NOTE: Regarding Table IV, information based on the table must be developed
and included in each project specification. Tables must clearly define the
systems to be inspected and the type of NDE required. Specify 100 percent NDE
when required by DM-22 and 49 CFR 195, as covered by paragraph entitled "Piping
Subject to 100 Percent NDE." Where appears, select 100 percent or random but
not both.
TABLE IV
EXAMINATIONS AND TESTS FOR VARIOUS MATERIALS AND SERVICES
Examinations or Tests Required
___________________________________________________________________________
[Magnetic Particle]
Material or [or] [Liquid Ultra-
Application Visual Radiographic Penetrant] sonic
___________________________________________________________________________
High-alloy austenitic
or nickel steels or
nickel alloys for
cryogenic service
and vacuum service
a. Tack welds Yes No No No
b. Root passes Yes No Yes No
c. Intermediate passes Yes No No No
d. Completed weld Yes 100 percent Yes(PT only) Yes for
for DN over wall
32 mm 60 50 mm and thickness
percent for over
DN 32 mm
and less
d. Completed weld Yes 100 percent Yes(PT only) Yes for
for NPS over wall
1 1/4 inches 1/2 inch and thickness
60 percent over
for NAPA PS 1 1/4
inches and less
High-alloy austenitic
or nickel steels or
nickel alloys for
other than cryogenic
or vacuum service
a. Tack welds Yes No No No
b. Root passes Yes No [No] [Yes] No
c. Intermediate passes Yes No No No
d. Completed weld Yes [100 percent] Yes(PT only) [No] [Yes]
[Random]
Stainless steel to
carbon steel
a. Completed weld Yes [No][Yes] Yes(PT only) No
[Random]
Carbon steel piping
systems
a. Tack welds Yes No No No
b. Root passes Yes No [No][Yes MT] No
c. Intermediate passes Yes No No No
d. Completed weld Yes [100 percent] [No][Yes MT] No
[Random]
___________________________________________________________________________
NOTE: Regarding Table V, information based on the table must be developed and
included in each project specification. Tables must clearly define the systems
to be inspected and the type of NDE required. Specify 100 percent NDE when
required by DM-22 and 49 CFR 195, as covered by paragraph entitled "Piping Subject
to 100 Percent NDE."
TABLE V
MANDATORY MINIMUM NONDESTRUCTIVE EXAMINATIONS FOR ASME B31.1 PIPING
___________________________________________________________________________
Temperatures over Temperatures between All others
400 degrees C and 175 degrees C and
at all pressures. 400 degrees C
inclusive and at
all pressures over
7100 kPa gage
___________________________________________________________________________
Buttwelds RT for DN over RT for over 50 mm Visual for
(Girth and 50 mm MT or PT DN with thickness all sizes
Longitudinal) for DN 50 mm over 19 mm. Visual and
and less. for all sizes with thicknesses.
thickness 19 mm or less.
Welded Branch RT for DN over RT for branch over Visual for
Connections 50 mm MT or PT 100 mm DN and all sizes
(Size indicated for DN 50 mm thickness of branch and
is Branch Size) and less. over 19 mm. Visual thicknesses.
for all sizes with
branch thickness
19 mm or less.
Fillet, Socket PT or MT for Visual for all sizes Visual for
Welds all sizes and and thicknesses. all sizes and
thicknesses. thicknesses.
NOTES:
1. Thickness refers to pressure boundary wall thickness (such as pipe wall, fitting wall, or nozzle wall thickness).
2. All welds must be given a visual examination in addition to type of specific nondestructive examination specified.
3. NPS-Nominal Pipe Size.
4. RT-Radiographic examination; MT-magnetic particle examination; PT-liquid penetrant examination.
5. RT of branch welds shall be performed before any nonintegral reinforcing material is applied.
6. The thickness of buttwelds is defined as the thicker of the two abutting ends after end preparation.
7. Temperatures and pressures shown are design.
8. In lieu of radiography of welded branch connections when required above, liquid penetrant or magnetic particle
examination is acceptable and, when used, shall be performed at the lesser of one-half of the weld thickness or each
50 mm of weld thickness and all accessible final weld surfaces.
9. For nondestructive examination of the pressure retaining component, refer to the standards listed in applicable
code or the manufacturing specifications.
TABLE V
MANDATORY MINIMUM NONDESTRUCTIVE EXAMINATIONS FOR ASME B31.1 PIPING
___________________________________________________________________________
Temperatures over Temperatures between All others
750 degrees F and 350 degrees F and
at all pressures. 750 degrees F
inclusive and at
all pressures over
1052 psig gage
___________________________________________________________________________
Buttwelds RT for NPS over RT for over 2 inch Visual for
(Girth and 2 inches MT or PT NPS with thickness all sizes
Longitudinal) for NPS 2 inches over 3/4 inch. and
and less. Visual for all thicknesses.
sizes with thickness
3/4 inch or less.
Welded Branch RT for NPS over RT for branch over Visual for
Connections 2 inch MT or PT 4 inch NPS and all sizes
(Size indicated for NPS 2 inch thickness of branch and
is Branch Size) and less. over 3/4 inch. thicknesses.
Visual for all sizes with branch
thickness 3/4 inch
or less.
Fillet, Socket PT or MT for Visual for all sizes Visual for
Welds all sizes and and thicknesses. all sizes and
thicknesses. thicknesses.
NOTES:
1. Thickness refers to pressure boundary wall thickness (such as pipe wall, fitting wall, or nozzle wall thickness).
2. All welds must be given a visual examination in addition to type of specific nondestructive examination specified.
3. NPS-Nominal Pipe Size.
4. RT-Radiographic examination; MT-magnetic particle examination; PT-liquid penetrant examination.
5. RT of branch welds shall be performed before any nonintegral reinforcing material is applied.
6. The thickness of buttwelds is defined as the thicker of the two abutting ends after end preparation.
7. Temperatures and pressures shown are design.
8. In lieu of radiography of welded branch connections when required above, liquid penetrant or magnetic particle
examination is acceptable and, when used, shall be performed at the lesser of one-half of the weld thickness or each
1/2 inch of weld thickness and all accessible final weld surfaces.
9. For nondestructive examination of the pressure retaining component, refer to the standards listed in applicable
code or the manufacturing specifications.