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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 12771-2008 Welded stainless steel pipes for liquid delivery, and the following main technical changes have been made with respect to GB/T 12771-2008:
——The application scope is modified (see clause 1; clause 1 of Edition 2008);
——The normative references are modified (see clause 2; clause 2 of Edition 2008);
——The manufacturing method code is modified and the delivery state of cold drawing (rolling) is deleted (see clause 3; clause 3 of Edition 2008) ;
——The tolerances for the outside diameter and wall thickness of steel pipes are modified (see 5.2; 5.2 of Edition 2008);
——The measurement method for the tolerance of outside diameter of steel pipe is added (see 5.2.1 and 5.2.2);
——The requirements for length of steel pipe are modified (see 5.3; 5.5 of Edition 2008);
——The requirements for out-of-roundness of steel pipe are modified (see 5.4; 5.3 of Edition 2008);
——The requirements for curvature per meter of steel pipe are modified, and those of the curvature of full-length are added (see 5.5; 5.4 of Edition 2008);
——12 steel grades and their technical requirements are added, and martensitic steel grades are deleted (see 6.1; 6.1 of Edition 2008);
——The steel pipe manufacturing method is modified (see 6.2.2; 6.2.2 of Edition 2008);
——The sampling requirements for steel pipe mechanical properties and the requirements for specified plastic elongation strength are modified (see 6.4.1; 6.4 of Edition 2008);
——The tensile requirements for welded joints are added (see 6.4.2);
——The sampling requirements for processing property are modified (see 6.5; 6.5.2 and 6.5.3 of Edition 2008);
——The requirements for rounding of hydraulic test pressure values are added (see 6.7.1);
——The air tightness test method is added to replace the hydraulic test (see 6.7.2);
——The requirements for grain size of stainless steels of some grades are added (see 6.8);
——The requirements for nondestructive testing are modified (see 6.9; 6.6 of Edition 2008);
——The requirements for weld reinforcement are modified (see 6.10.2 and 6.10.3; 6.7.3 of Edition 2008);
——The requirements for repair welding are modified (see 6.11; 6.7.2 of Edition 2008);
——The requirements for marking are modified (see 9.1; clause 9 of Edition 2008);
This standard was proposed by China Iron and Steel Association.
This standard is under jurisdiction of SAC/TC 183 National Technical Committee on Iron and Steel of Standardization Administration of China.
The previous editions of this standard are as follows:
——GB/T 12771-1991, GB/T 12771-2000 and GB/T 12771-2008.
Welded stainless steel pipes for fluid transport
1 Scope
This standard specifies the classification and code, order contents, dimensions, shapes and weights, technical requirements, test methods, inspection rules, and packaging, marking and quality certification of welded stainless steel pipes for fluid transport.
This standard is applicable to welded stainless steel pipes for fluid transport (hereinafter referred to as steel pipes).
2 Normative references
The following referenced documents are indispensable for the application 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 222 Permissible tolerances for chemical composition of steel products
GB/T 223.9 Iron, steel and alloy - Determination of aluminum content - Chrom azurol S photometric method
GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual titration or potentiometric titration method
GB/T 223.18 Methods for chemical analysis of iron, steel and alloy - The sodium thiosulfate separation iodimetric method for the determination of copper content
GB/T 223.19 Methods for chemical analysis of iron, steel and alloy - The neocuproine-chloroform extraction photometric method for the determination of copper content
GB/T 223.23 Iron, steel and alloy - Determination of nickel content - The dimethylglyoxime spectrophotometric method
GB/T 223.25 Methods for chemical analysis of iron, steel and alloy - The dimethylglyoxime gravimetric method for the determination of nickel content
GB/T 223.26 Iron, steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method
GB/T 223.28 Methods for chemical analysis of iron, steel and alloy - The α-benzoinoxime gravimetric method for the determination of molybdenum content
GB/T 223.36 Methods for chemical analysis of iron, steel and alloy - The neutral titration method for the determination of nitrogen content after distillation separation
GB/T 223.37 Methods for chemical analysis of iron, steel and alloy - The indophenal blue photometric methods for the determination of nitrogen content after distillation separation
GB/T 223.40 Iron, steel and alloy - Determination of niobium content by the sulphochlorophenol spectrophotometric method
GB/T 223.59 Iron, steel and alloy - Determination of phosphorus content - Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric method
GB/T 223.60 Methods for chemical analysis of iron, steel and alloy - The perchloric acid dehydration gravimetric method for the determination of silicon content
GB/T 223.63 Methods for chemical analysis of iron, steel and alloy - The sodium (potassium) periodate photometric method for the determination of manganese content
GB/T 223.68 Methods for chemical analysis of iron, steel and alloy - The potassium iodate titration method after combustion in the pipe furnace for the determination of sulfur content
GB/T 223.69 Iron, steel and alloy - Determination of carbon contents - Gas-volumetric method after combustion in the pipe furnace
GB/T 223.84 Steel and alloy - Determination of titanium content - Diantipyrylmethane spectrophotometric method
GB/T 223.85 Steel and iron - Determination of sulfur content - Infrared absorption method after combustion in an induction furnace
GB/T 223.86 Steel and iron - Determination of total carbon content - Infrared absorption method after combustion in an induction furnace
GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 241 Metal materials - Tube - Hydrostatic pressure test
GB/T 245 Metallic materials - Tube - Flanging test
GB/T 246 Metallic materials - Tube - Flattening test
GB/T 2102 Acceptance, packing, marking and quality certification of steel pipe
GB/T 2650 Impact test methods on welded joints
GB/T 2651 Tensile test method on welded joints
GB/T 2653 Bend test methods on welded joints
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
GB/T 3323 Radiographic examination of fusion welded joints in metallic materials
GB/T 4334-2008 Corrosion of metals and alloys - Test methods for intergranular corrosion of stainless steels
GB/T 6394 Determination of estimating the average grain size of metal
GB/T 7735-2016 Automated eddy current testing of seamless and welded (except submerged arc-welded) steel tubes for detection of imperfections
GB/T 11170 Stainless steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (Routine method)
GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition
GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method)
GB/T 20124 Steel and iron - Determination of nitrogen content - Thermal conductimetric method after fusion in a current of inert gas (routine method)
GB/T 21835 Dimensions and masses per unit length of welded steel pipes
NB/T 47013.2 Nondestructive testing of pressure equipment - Part 2: Radiographic testing
NB/T 47013.11 Non-destructive testing of pressure equipment - Part 11: Testing by X-ray digital radiography
3 Classification and code
3.1 Steel pipes are classified and coded according to manufacturing methods and radiographic testing as follows:
a) I——the steel pipe is manufactured by double-side automatic welding method, with 100% welds subjected to radiographic inspection in full-length;
b) II——the steel pipe is manufactured by single-sideautomatic welding method, with 100% welds subjected to radiographic inspection in full-length;
c) III——the steel pipe is manufactured by double-side automatic welding method, with partial welds subjected to radiographic inspection;
d) IV——the steel pipe is manufactured by single-side automatic welding method, with partial welds subjected to radiographic inspection;
e) V——the steel pipe is manufactured by double-side automatic welding method, with welds not subjected to radiographic inspection;
f) Ⅵ——the steel pipe is manufactured by single-side automatic welding method, with welds not subjected to radiographic inspection.
3.2 Steel pipes are classified and coded according to delivery state as follows:
a) in as-welded state +H;
b) in heat treatment state +T;
c) in polished state +SP.
4 Order contents
The contract or order for ordering steel pipes according to this standard shall include the following contents:
a) serial number of this standard;
b) product name;
c) steel grade;
d) dimension and specification (outside diameter × wall thickness, in mm);
e) the order quantity (total weight or total length);
f) delivery state;
g) special requirements.
5 Dimension, shape and weight
5.1 Outside diameter and wall thickness
The nominal outside diameter (D) and nominal wall thickness (S) of steel pipes shall be in accordance with those specified in GB/T 21835. As required by the purchaser, steel pipes with other outside diameter and wall thickness may be supplied upon agreement between the supplier and purchaser.
5.2 Tolerances for outside diameter and wall thickness
5.2.1 For steel pipes with an outside diameter not exceeding 508mm, if the ratio of wall thickness to outside diameter is greater than 3%, the difference between the measured maximum/minimum outside diameters of any cross section of the steel pipe and the nominal outside diameter shall meet those specified in Table 1; for thin-walled steel pipe (steel pipes with the ratio of wall thickness to outside diameter not greater than 3%), the difference between the average outside diameter (the average of the measured maximum and minimum outside diameters of any cross section) and the nominal outside diameter of the steel pipe shall meet those specified in Table 1.
5.2.2 For steel pipes with an outside diameter greater than 508mm, the difference between the outside diameter converted from the measured circumference and the nominal outside diameter shall meet those specified in Table 1.
5.2.3 The tolerances for nominal wall thickness of steel pipes shall meet those specified in Table 1.
5.2.4 If the dimension tolerance level of the steel pipe is not stated in the contract, the steel pipes shall be supplied according to the outside diameter tolerance of general precision grade.
5.2.5 As required by the purchaser and indicated in the contract upon the agreement between the supplier and the purchaser, steel pipes with dimension tolerances beyond those specified in Table 1 may also be supplied.
GB/T 12771-2019 Welded stainless steel pipes for fluid transport English
Foreword i
1 Scope
2 Normative references
3 Classification and code
4 Order contents
5 Dimension, shape and weight
6 Technical requirements
7 Test methods
8 Inspection rules
9 Packaging, marking and quality certification
