NB/T 47014-2023 Welding procedure qualification for pressure equipments
1 Scope
This document specifies the rules, test methods and acceptance criteria for welding procedure qualification of pressure equipment (boilers, pressure vessels and pressure pipelines).
This document is applicable to the welding procedure qualification for welding processes such as oxyfuel gas welding, shielded metal 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 and electron beam welding.
This document is not applicable to welding procedure qualification for gas cylinders.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
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
GB/T 1591 High strength low alloy structural steels
GB/T 2040 Copper and copper alloy sheet
GB/T 2054 Nickel and nickel alloy plate and sheet
GB/T 2653 Bend test methods on welded joints
GB/T 2882 Nickel and nickel alloys tube
GB/T 2965 Titanium and titanium alloy bars
GB/T 3077 Alloy structure steels
GB/T 3087 Seamless steel tubes and pipes for low and medium pressure boiler
GB/T 3091 Welded steel pipes for low pressure liquid delivery
GB/T 3274 Hot-rolled plates, sheets and strips of carbon structural steels and high strength low alloy structural steels
GB/T 3280 Cold rolled stainless steel plate, sheet and strip
GB/T 3375 Welding terminology
GB/T 3531 Steel plates for low temperature pressure vessels
GB/T 3620.1 Designation and composition of titanium and titanium alloys
GB/T 3621 Titanium and titanium alloy plate and sheet
GB/T 3624 Titanium and titanium alloy seamless tubes
GB/T 3625 Titanium and titanium alloy tube for condensers and heat exchangers
GB/T 3670 Covered electrodes for manual metal arc welding of copper and copper alloys
GB/T 3880 (All Parts) Wrought aluminium and aluminium alloy plates, sheets and strips for general engineering
GB/T 4237 Hot rolled stainless steel plate, sheet and strip
GB/T 4423 Copper and copper alloy cold-drawn rod and bar
GB/T 4435 Nickel and nickel alloys bars
GB/T 4437.1 Aluminium and aluminium alloy extruded tubes - Part 1: Seamless tubes
GB/T 5310 Seamless steel tubes and pipes for high pressure boiler
GB/T 6479 Seamless steel tubes for high-pressure chemical fertilizer equipments
GB/T 6614 Titanium and titanium alloy castings
GB/T 6892 Wrought aluminium and aluminium alloys extruded profiles for general engineering
GB/T 6893 Aluminium and aluminium alloys cold drawn (rolled) tubes
GB/T 8163 Seamless steel pipes for liquid service
GB/T 8769 Zirconium and zirconium alloy bars and wires
GB/T 8890 Seamless copper alloy tube for condenser and heat-exchanger
GB/T 9460 Solid wires and rods for fusion welding of copper and copper alloys
GB/T 9711 Petroleum and natural gas industries - Steel pipe for pipeline transportation systems
GB/T 9948 Seamless steel tubes for petroleum cracking
GB/T 11352 Carbon steel castings for general engineering purpose
GB/T 12228 General purpose industrial valves - Specification of carbon steel forgings
GB/T 12229 General purpose industrial valves - Specification of carbon steel castings
GB/T 12230 General purpose industrial valves - Specification of stainless steel castings
GB/T 12771 Welded stainless steel pipes for fluid transport
GB/T 13237 Cold rolled quality carbon structural steel sheets and strips
GB/T 13296 Seamless stainless steel tubes for boiler and heat exchanger
GB/T 13401 Steel buttwelding pipe fittings - Technical specification
GB/T 13814 Nickel and nickel alloy covered welding electrodes
GB/T 14845 Titanium sheet for plate heat exchangers
GB/T 14976 Seamless stainless steel pipes for fluid transport
GB/T 15008 Corrosion-resistant alloy bars
GB/T 15620 Nickel and nickel alloy wires and rods
GB/T 16253 Steel castings for pressure purposes
GB/T 16598 Titanium and titanium alloy disc and ring
GB/T 17791 Seamless copper and copper alloys tube for air conditioner and refrigeration equipment
GB/T 18984 Seamless steel tubes for low-temperature-service piping
GB/T 19189 Quenched and tempered high strength steel plates for pressure vessels
GB/T 21183 Zirconium and zirconium alloy sheet, strip and foil
GB/T 21832 (All Parts) Welded austenitic-ferritic (duplex) stainless steel tubes and pipes
GB/T 21833 (All Parts) Seamless austenitic-ferritic (duplex) stainless steel tubes and pipes
GB/T 24511 Stainless steel and heat resisting steel plate, sheet and strip for pressure equipments
GB/T 24593 Welded austenitic stainless steel tubes for boiler and heat exchanger
GB/T 26283 Zirconium and zirconium alloy seamless tubes
GB/T 29168.2 Petroleum and natural gas industries - Induction bends, fittings and flanges for pipeline transportation systems - Part 2: Fittings
GB/T 29168.3 Petroleum and natural gas industries - Induction bends, fittings and flanges for pipeline transportation systems - Part 3: Flanges
GB/T 30059 Seamless corrosion-resisting alloy tubes for heat-exchanger
GB/T 30568 Zirconium and zirconium alloy forgings
GB/T 32964 Welded stainless steel pipes for liquefied natural gas
GB/T 34275 Pressure piping code - Long-distance pipeline
GB/T 38106 Aluminum and aluminum alloy plates and sheets for pressure vessel
GB/T 38512 Aluminum and aluminum alloy tubes for the pressure vessel
GB/T 39255 Gases and gas mixtures for welding and cutting processes
NB/T 47008 Carbon and alloy steel forgings for pressure equipment
NB/T 47009 Alloy steel forgings for low temperature pressure equipment
NB/T 47010 Stainless and heat-resisting steel forgings for pressure equipment
NB/T 47013 (All parts) Nondestructive testing of pressure equipments
NB/T 47018 (All parts) Specification of welding materials for pressure equipment
NB/T 47019.2 Purchase technical specification for boiler & heater exchanger tubes - Part 2: Non-alloy and alloy steel with room temperature properties
NB/T 47019.3 Purchase technical specification for boiler & heater exchanger tubes/pipes - Part 3: Non-alloy and alloy steel with specified elevated temperature properties
NB/T 47028 Nickel and nickel alloy forgings for pressure vessels
NB/T 47029 Aluminium and aluminium alloy forgings for pressure vessels
NB/T 47046 Nickel-nickel alloy plate for pressure equipments
NB/T 47047 Nickel-nickel alloy seamless tube and pipe for pressure equipments
JB/T 10087 Pressure steel casting of steam turbine - Specification
YS/T 753 Zirconium and zirconium alloy sheet and plate for pressure vessel
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 3375 and the following apply. In case of any inconsistency, those given in this document shall prevail.
3.1
preliminary welding procedure specification (pWPS)
welding procedure document prepared for performing welding procedure qualification
3.2
welding procedure qualification
test process and result evaluation carried out to verify the correctness of the proposed welding procedure for the weldment
In this document, welding procedure qualification refers to the process of verification test and result evaluation for pWPS based on whether the mechanical properties and bending properties of welded joints, the chemical composition and corrosion resistance of corrosion-resistant surfacing layer, or the bending properties of surfacing weldment, which are all welded according to pWPS, meet the requirements.
3.3
procedure qualification record (PQR)
report documenting the verification test and their inspection results, and evaluating the proposed pWPS
3.4
welding procedure specification (WPS)
welding procedure document prepared on the basis of a qualified PQR to guide the product welding
3.5
welding working instruction (WWI)
detailed document on processing and operation during manufacture of weldment, which is the working instruction used by welders while conducting welding to ensure the reproducibility of quality during construction
3.6
weldment
pressure equipment or its parts and components that are connected by welding or have a surfacing layer. A weldment consists of two parts, namely, base metal and welded joint (or surfacing layer)
3.7
test coupon
weldment welded in accordance with a predetermined welding procedure for use in welding tests. A test coupon consists of two parts, namely, base metal and welded joint (or surfacing layer)
3.8
mixed flux
mixed flux prepared by mixing two different types of flux in a certain proportion
3.9
post weld heat treatment (PWHT)
thermal process that can change the microstructure, properties and residual welding stress of a welded joint
3.10
lower transformation temperature
phase-transition temperature at which austenite begins to form during heating
3.11
upper transformation temperature
phase-transition temperature at which austenite transformation is completed during heating
3.12
face bend
bend of a bending test specimen whose tensile surface is the face of weld. The side with larger weld width is the face of weld. In the case that the weld width is equal on both sides, the side of the weld where the cover layer is completed first is the face of weld
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3.13
root bend
bend of a bending test specimen whose tensile surface is the root surface
3.14
side bend
bend of a bending test specimen whose tensile surface is the cross section of the welded joint
3.15
electrogas welding
arc welding process in which a joint is made in the vertical position by means of electric arc between a continuously fed welding wire and a molten pool, backing shoe and module are used to force the molten weld metal into shape, solid-cored welding wire, metal powder-cored welding wire or flux-cored welding wire may be adopted, and protection is offered by a single gas or a gas mixture (no shield gas is required for self-shielded flux-cored welding wire)
3.16
stud arc welding
welding process in which the molten part at the end of a metal stud (or similar part) and that on the surface of a workpiece are fused together under the action of electric arc and external pressure, without filler metal, and with or without shield gas or flux
3.17
supplemental filler metal
broken welding wire, solid-cored welding wire, metal powder or composite metal material, other than the consumable electrode, which is melted into weld
3.18
imperfection
all discontinuities, imperfections, unsoundness, inhomogeneities, etc.
3.19
weld imperfection
a general term for discontinuities, inhomogeneities, non-densities and other poor connections in the microstructure and structure of a welded joint
3.20
welding defect
weld imperfections exceeding the specified limits
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3.21
heat input of strip surfacing welding
amount of heat input to a unit area of surfacing metal from a welding heat source during strip surfacing, calculated using (J/mm2)
3.22
buttering
practice of surfacing one or both groove faces of a joint to add material before the joint is ready for final welding, in order to provide a suitable transition layer of weld deposit for subsequent welding
…
4 General
4.1 In addition to the requirements of this document, the welding procedure qualification for pressure equipment shall also comply with the requirements of relevant standards and technical documents for boilers, pressure vessels and pressure pipeline products.
4.2 The general process of welding procedure qualification is: According to the weldability of metal materials and welding materials, a pWPS is prepared in accordance with the design documents and manufacturing processes, test coupons are then prepared, from which the test specimens are taken to test whether the welded joint or corrosion-resistant surfacing layer meets the specified requirements, and finally a PQR is formed to evaluate the pWPS.
4.3 The welding procedure qualification shall be carried out in the unit. 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, and the welding personnel with skilled operation skills of the unit shall be assigned to weld the test coupon using the equipment of the unit.
4.4 The qualified welding procedure refers to the general welding procedure qualification factors, the important factors and supplementary factors among the special welding procedure qualification factors for butt welds and fillet welds, or the procedure factors subjected to re-qualification among the procedure qualification factors for corrosion-resistant cladding, which are listed in the qualified PQR.
4.5 See Annex A for the WPS flow chart.
5 Welding procedure qualification factors and categorization
5.1 General welding procedure qualification factors and classification of various welding processes
5.1.1 Welding processes and classification
The welding processes are classified into the following categories: oxyfuel gas welding, shielded metal 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 and electron beam welding.
F
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 General
5 Welding procedure qualification factors and categorization
6 Welding procedure qualification for butt weld and fillet weld
7 Corrosion-resistant cladding procedure qualification
8 Others
Annex A (Informative) WPS flow chart
Annex B (Normative) Supplementary provisions for base metal, filler metal and welding process
Annex C (Normative) Welding procedure qualification for butt welds with buttering
Annex D (Normative) Welding procedure qualification for stainless steel-steel clad plate
Annex E (Normative) Welding procedure qualification for heat exchange tubes and tube sheets
Annex F (Normative) Stud arc welding procedure qualification
Annex G (Informative) Recommended PQR format
Annex H (Informative) English abbreviations and codes commonly used for welding procedure qualification
