NB/T 47014-2023 English PDF (NB/T47014-2023)

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NB/T 47014-2023: Welding procedure qualification for pressure equipments
NB/T 47014-2023
NB
ENERGY INDUSTRY STANDARD OF
THE PEOPLE’S REPUBLIC OF CHINA
ICS 25.160.10
CCS J 33
Replacing NB/T 47014-2011
Welding procedure qualification for pressure equipments
ISSUED ON: DECEMBER 28, 2023
IMPLEMENTED ON: JUNE 28, 2024
Issued by: National Energy Administration
Table of Contents
Foreword ... 3
1 Scope ... 6
2 Normative references ... 6
3 Terms and definitions ... 10
4 General ... 14
5 Welding procedure qualification factors and classification ... 14
6 Welding procedure qualification for butt welds and fillet welds ... 41
7 Qualification of corrosion resistant cladding procedure ... 64
8 Others ... 74
Appendix A (Informative) Welding procedure specification flow chart ... 75
Appendix B (Normative) Supplementary provisions for base materials, filler metals,
welding methods ... 76
Appendix C (Normative) Welding procedure qualification of butt welds with buttering
... 79
Appendix D (Normative) Welding procedure qualification of stainless steel-steel
composite plates ... 81
Appendix E (Normative) Welding procedure qualification of heat exchange tubes and
tube sheets ... 84
Appendix F (Normative) Stud arc welding procedure qualification ... 89
Appendix G (Informative) Recommended format for welding procedure qualification
record ... 95
Appendix H (Informative) Common English abbreviations and codes for welding
procedure qualification ... 105
Welding procedure qualification for pressure equipments
1 Scope
This document specifies the rules, test methods, qualified indicators for welding
procedure qualification for pressure equipment (boilers, pressure vessels, pressure
pipes).
This document is applicable to welding procedure qualification for welding methods
such as gas welding, arc welding, submerged arc welding, gas tungsten arc welding,
gas metal arc welding (including flux-cored arc welding), electroslag welding, plasma
arc welding, friction welding, electrogas welding, stud arc welding, electron beam
welding.
This document is not applicable to welding procedure qualification for gas cylinders.
2 Normative references
The contents of the following documents constitute essential clauses of this document
through normative references in the text. Among them, for referenced documents with
dates, only the version corresponding to that date applies to this document; for
referenced documents without dates, the latest version (including all amendments)
applies to this document.
GB/T 150.2 Pressure vessels - Part 2: Materials
GB/T 151 Heat exchangers
GB/T 228 (all parts) Metallic materials - Tensile testing
GB/T 229 Metallic materials - Charpy pendulum impact test method
GB/T 699 Quality carbon structure steels
GB/T 700 Carbon structural steels
GB/T 711 Hot-rolled quality carbon structural steel plates sheets and strips
GB/T 713 Steel plates for boilers and pressure vessels
GB/T 1176 Casting copper and copper alloys
GB/T 1527 Drawn tube of copper and copper alloys
strip surfacing. The calculation formula is: 60×I×U/(V × bandwidth) (J/mm2).
3.22
Buttering
Before the joint is prepared for final welding, pre-welding is performed on one or
two groove surfaces of the joint to increase material, in order to provide a suitable
transition layer weld for subsequent welding.
4 General
4.1 In addition to complying with the provisions of this document, the welding
procedure qualification of pressure equipment shall also comply with the requirements
of relevant standards and technical documents for boilers, pressure vessels, pressure
piping products.
4.2 The general process of welding procedure qualification is: According to the
weldability of metal materials and welding materials, formulate preliminary welding
procedure specifications according to the provisions of design documents and
manufacturing process; prepare test coupons; prepare specimens; detect whether the
welding joints or corrosion-resistant cladding layers meet the specified requirements;
form a welding procedure qualification record to evaluate pWPS.
4.3 Welding procedure qualification shall be carried out in the organization. The
equipment and instruments used for welding procedure qualification shall be in normal
working condition; the metal materials and welding materials shall meet the
corresponding standards; the welding personnel with skilled operation skills in the
organization shall use the equipment of the organization to weld the test coupons.
4.4 The qualified welding procedure refers to the general welding procedure
qualification factors listed in the qualified welding procedure qualification record, the
important factors and supplementary factors in the special welding procedure
qualification factors for butt welds and fillet welds, or the re-evaluated process factors
in the corrosion-resistant cladding process qualification factors.
4.5 See Appendix A for the welding procedure qualification flow chart.
5 Welding procedure qualification factors and classification
5.1 General welding procedure qualification factors and classification for various
welding methods
5.1.1 Welding methods and classification
6 Welding procedure qualification for butt welds and fillet
welds
6.1 General qualification rules for various welding methods
6.1.1 Qualification rules for welding methods
When the welding method is changed, the welding procedure qualification needs to be
re-performed.
6.1.2 Qualification rules for base materials
6.1.2.1 Qualification rules for categories (except stud welding and friction welding):
a) When the base material category number is changed, so the welding procedure
qualification needs to be re-performed;
b)For welding of a certain category of base materials Fe-1 ~ Fe-5A, qualified
welding procedures such as arc welding, submerged arc welding, gas shielded arc
welding, gas tungsten shielded welding, plasma arc welding with wire are
applicable to welding of the base materials of this category with the base materials
of lower category;
c) Except for b), for welding of base materials of different categories, even if the
welding procedure of each base material is qualified, the welding joint still needs
to be re-qualified;
d) When the heat affected zone specifies impact, the preliminary welding procedures
for welding of two categories (groups) of base materials are the same as the
welding procedure for their respective qualified welding, then the welding of
these two categories (groups) of base materials does not need to be re-qualified.
6.1.2.2 Group qualification rules (except stud welding and friction welding):
a) Except for the following provisions, when the base material group number
changes, the welding procedure qualification needs to be re-performed;
b) The welding procedure that has been qualified for a base material is applicable to
other base materials of the same group number;
c) In the same category number, the welding procedure that has been qualified for a
base material of a higher group number is applicable to the welding of the base
material of the higher group number with the base material of the lower group
number;
d) The welding procedure that has been qualified for a base material of the Fe-1-2
group number is applicable to the base material of the Fe-1-1 group number.
6.1.2.3 Base material qualification rules for friction welding:
a) When the nominal composition or tensile strength grade of the base material
changes, the welding procedure qualification needs to be re-performed;
b) When two base materials of different nominal composition or tensile strength
grades are welded together, even if the welding procedure qualification of each
base material is qualified, the welding joint still needs to be re-performed.
6.1.3 Filler metal qualification rules
6.1.3.1 Changing the filler metal category number requires re-qualification of the
welding procedure, except when a filler metal with a higher strength level replaces a
filler metal with a lower strength level to weld Fe-1 and Fe-3 base materials.
6.1.3.2 When performing submerged arc welding and metal arc gas shielded welding,
the addition, cancellation or volume change of supplemental filler metal exceeding 10%
requires re-qualification of the welding procedure.
6.1.3.3 When an impact test is required, among filler metals of the same category
number, replacing a filler metal with a lower impact absorption energy qualified index
with a higher filler metal (except when the impact absorption energy qualified index is
lower, it can still meet the requirements of this document or design documents) or
replacing a basic coated electrode with a non-basic coated electrode are both additional
factors, an impact toughness test needs to be added.
6.1.3.4 For welding materials for submerged arc welding of austenitic stainless steel in
NB/T 47018.4, if the flux manufacturing method (melting flux, sintering flux) is
changed, the welding procedure qualification must be re-performed.
6.1.4 Qualification rules for post-weld heat treatment
6.1.4.1 If the post-weld heat treatment category is changed, the welding procedure
qualification must be re-performed.
6.1.4.2 When impact testing is required, except for gas welding, stud arc welding,
friction welding, the welding procedure qualification must be re-performed after the
holding temperature or holding time range of the post-weld heat treatment is changed.
The post-weld heat treatment of the test coupon shall be basically the same as the post-
weld heat treatment of the weldment during the manufacturing process. When the post-
weld heat treatment is performed below the lower transformation temperature, the
holding time of the test coupon shall not be less than 80% of the cumulative holding
time of the weldment during the manufacturing process. The holding time of multiple
post-weld heat treatments with the same holding temperature can be accumulated into
When the qualified welding procedure is used for weldment, one or several welding
methods (or welding procedures) can be used; however, the major factors and
supplementary factors shall be kept unchanged, wherein the thickness of the base
material and weld metal of the test coupon as qualified by each welding method (or
welding procedure) is applicable to the effective range of the base material thickness
and weld metal thickness of the weldment, according to the provisions of this document.
6.3.5 Test coupon preparation
6.3.5.1 The welding of base material, welding materials, test coupons must comply with
the preliminary welding procedure specification.
6.3.5.2 For the test coupons qualified in combination, the thickness of the weld metal
welded by each welding method shall be recorded, but the weld excess height shall not
be included.
6.3.5.3 The number and size of the test coupons shall meet the requirements for test
coupon preparation. The test coupons may also be cut directly from the weldment.
When the diameter of the tubular butt weld test coupon is ≥ DN500, the weld shall be
welded in the vertical welding position. The weld length shall meet the requirements
for specimen preparation, meanwhile there is no need to weld the entire circumferential
weld.
6.4 Inspection requirements and result evaluation
6.4.1 Inspection of butt weld test coupon and specimen
6.4.1.1 Items for test coupon inspection: Appearance inspection, nondestructive testing,
mechanical property test, bending test.
6.4.1.2 The results of appearance inspection and nondestructive testing (according to
NB/T 47013) shall not show cracks.
6.4.1.3 Mechanical property test and bending test:
a) The number of samples for mechanical property test and bending test shall comply
with the provisions of Table 10, unless otherwise specified.
b) When impact test is required, Charpy V-notch impact test shall be carried out only
on steel and aluminum-magnesium alloy and austenitic stainless steel welded
joints with magnesium content exceeding 3%; only weld metal impact specimens
shall be taken for aluminum-magnesium alloy and austenitic stainless steel
welded joints.
c) When the test coupon adopts two or more welding methods (or welding
procedures with different major factors and supplementary factors), the tensile
surface of the tensile specimen and the bending specimen shall include the weld
6.4.1.5 Tensile test
6.4.1.5.1 Sampling and processing requirements:
a) The weld excess height of the specimen shall be removed mechanically to make
it flush with the base material; sampling on electron beam welded tubular butt
weld test coupon shall avoid the overlap where the beam is attenuated.
b) For test coupon which has a thickness less than or equal to 30 mm, full-thickness
tensile specimens are used. The specimen thickness shall be equal to or close to
the base material thickness T of test coupon.
c) When the testing machine is limited in capacity and cannot perform full-thickness
tensile tests, the test coupon can be evenly layered and sampled in the thickness
direction. The thickness of the specimens after equal division shall be close to the
maximum thickness that the testing machine can test. The test of two or more
equally divided specimens replaces the test of one full-thickness specimen.
6.4.1.5.2 Test specimen form:
a) Compact plate joint with shoulder plate tensile test specimen (as shown in Figure
4) is applicable to butt weld test coupons of all thickness plates;
b) Compact pipe joint with shoulder plate tensile test specimen type I (as shown in
Figure 5) is applicable to all wall thickness tubular butt weld test coupons, which
have an outer diameter greater than 76 mm;
c) Compact pipe joint with shoulder plate tensile test specimen type II (as shown in
Figure 6) is applicable to tubular butt weld test coupons, which have an outer
diameter less than or equal to 76 mm;
d) Pipe joint full section tensile test specimen (as shown in Figure 7) is applicable to
tubular butt weld test coupons, which have an outer diameter less than or equal to
76 mm.