GB/T 13401-2017 English PDF (GBT13401-2017)
GB/T 13401-2017 English PDF (GBT13401-2017)
GB/T 13401-2017: Steel buttwelding pipe fittings -- Technical specification
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
Partially replacing GB/T 12459-2005, GB/T 13401-2005
Steel buttwelding pipe fittings - Technical
ISSUED ON: FEBRUARY 28, 2017
IMPLEMENTED ON: SEPTEMBER 01, 2017
Issued by: General Administration of Quality Supervision, Inspection and Quarantine;
Standardization Administration of the People's Republic of
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Order content ... 6
4 Materials ... 7
5 Manufacturing ... 8
6 Heat treatment ... 12
7 Inspection and testing ... 14
8 Welding repair ... 23
9 Surface protection and packaging ... 24
10 Product quality certificate ... 24
Annex A (normative) ... 26
Additional requirements ... 26
Annex B (informative) Raw materials to manufacture pipe fittings ... 28 Steel buttwelding pipe fittings - Technical
This Standard specifies technical requirements such as order content, materials, manufacturing, heat treatment, inspection and testing, welding repair, surface protection and packaging, and product quality certificate for steel buttwelding pipe fittings (hereinafter referred to as pipe fittings).
This Standard is applicable to pipe fittings specified in GB/T 12459. Other pipe fittings may refer to this Standard for use.
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 150.4-2011, Pressure Vessels - Part 4: Fabrication, inspection and
testing, and acceptance
GB/T 222, Method of sampling steel for determination of chemical
composition and permissible variations for product analysis
GB/T 223 (all parts), Iron, steel and alloy - Chemical analysis methods GB/T 228.1, Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 229, Metallic Materials - Charpy Pendulum Impact Test Method
GB/T 2975, Steel and Steel Products - Location and Preparation of Test
Pieces for Mechanical Testing
GB/T 4334, Corrosion of metals and alloys - Test methods for intergranular corrosion of stainless steels
GB/T 4336, Carbon and low-alloy steel - Determination of multi-element
contents - Spark discharge atomic emission spectrometric method (routine method)
b) Material level of pipe fittings (see 4.2);
c) Nominal size (standard or designated; when the outer diameter is selected as GB/T 12459 series II, it shall be marked "-II"), nominal wall thickness (see 4.2.2 of GB/T 12459-2017);
d) Structure, seamless or welded (if not specified, the fitting manufacturer can choose any kind);
e) Product standard number, GB/T 12459 and GB/T 13401 (including version number);
f) Number of pieces;
g) Required additional requirements (see Annex A) or supplementary
4.1 The raw materials for manufacturing pipe fittings include seamless pipes, straight seam electrofusion welded pipes, plates, bars and forgings. The chemical composition shall meet the requirements of Table 1. The pipe fitting manufacturer shall conduct chemical composition analysis of the raw materials used according to the melting furnace number. Analysis method is according to GB/T 223 or GB/T 4336, GB/T 11170, to ensure that it meets the requirements of Table 1. The allowable deviation of chemical composition analysis of the finished product shall meet the requirements of GB/T 222.
4.2 The contents represented by pipe fitting material level codes are as follows: a) CF is the abbreviation of carbon steel fitting, that is, carbon steel pipe fitting. The following number is the minimum tensile strength of pipe fitting. The letter K in the suffix represents that the level must be guaranteed to pass the impact test at 20??C.
b) AF is the abbreviation of alloy steel fitting, that is, alloy steel pipe fitting. The following figures use characteristic figures familiar in the industry. The letter G in the suffix indicates that the level has higher tensile properties. c) LF is the abbreviation of low temperature steel fitting, that is, low temperature steel pipe fitting. The following number is the minimum tensile strength of the pipe fitting. The suffix letters K1, K2, K3 and K4 represent the lowest operating temperature at -20??C, -46??C, -100??C and -196??C
d) SF is the abbreviation of stainless steel fitting, that is, stainless steel pipe 6.3 When the following conditions are met, heat treatment is not necessary: a) Carbon steel pipe fittings (excluding carbon steel pipe fittings in low- temperature steel) that thermoforming and final forming temperature is
between 700??C~980??C and are placed in still air and cooled;
b) Forged carbon steel pipe fittings (excluding carbon steel pipe fittings in low-temperature steel) that are less than or equal to DN100, the final
forming temperature is between 700??C~980??C and are placed in still air
c) Pipe fittings manufactured by direct cutting using raw materials that have been heat treated before exiting the factory.
6.4 For carbon steel welded pipe fittings with a nominal wall thickness greater than 19mm and welded after thermoforming (excluding carbon steel pipe fittings in low-temperature steel), if the requirements of 6.3a) are met, it can adopt post- weld stress relief heat treatment.
6.5 For carbon steel welded pipe fittings with a nominal wall thickness less than or equal to 19mm and welded after thermoforming (excluding carbon steel pipe fittings in low-temperature steel), if the requirements of 6.3a) are met, after negotiation between the supplier and the purchaser, it may not conduct
thermoforming. However, the suffix letters -NH shall be added after the delivery document and the material level of pipe fittings marked by physical object, such as CF415K-NH.
6.6 For austenitic stainless steel pipe fittings, after negotiation between the supplier and the purchaser, thermoforming is not required. However, the suffix letters -NH shall be added after the delivery document and the material level of pipe fittings marked by physical object, such as SF304-NH.
6.7 The heat treatment furnace shall be equipped with an automatic
temperature measuring and recording device. A complete record can be
obtained. The effective heating zone of the heat treatment furnace is measured according to the regulations of GB/T 9452. The temperature uniformity of the effective heating zone is ??14??C.
7 Inspection and testing
7.1 Mechanical properties
7.1.1 Sample of mechanical properties
22.214.171.124 The sample shall be prepared from the pipe that has been heat treated (or is formed without heat treatment). It can also be obtained from the sample inspection piece by piece according to NB/T 47013.4 or relevant specifications. Level I is conforming.
7.3.3 In addition to the provisions of 7.3.5, when the weld of the welded pipe fitting is completed by the pipe fitting manufacturer, the full length of welds of welded pipe fittings shall be inspected according to NB/T 47013.2 or relevant specifications. Level II is conforming (excluding stud end manufactured in the method in 5.6).
7.3.4 In addition to the provisions of 7.3.5, for welded pipe fittings made of straight seam welded pipes, if the weld has been 100% radiographically
inspected by the welded pipe manufacturer and conforming for level II, the welds of pipe fittings can no longer be inspected by radiography, unless otherwise required. If the weld of the welded pipe is not 100% radiographically inspected by the welded pipe manufacturer, then the full length of the weld of welded pipe fittings shall be inspected according to NB/T 47013.2 or relevant specifications. Level II is conforming.
7.3.5 For welded pipe fittings that do not require weld radiographic testing, after negotiation between the supplier and the purchaser, the radiographic testing is not required for the welds. However, the suffix letters -NX shall be added after the delivery document and the material level of pipe fittings marked by physical object, such as CF370-NX.
7.3.6 In addition to the above regulations, non-destructive testing can be carried out according to the content negotiated by the supplier and the purchaser. For example, magnetic powder, penetration and ultrasonic testing required
7.3.7 Operators engaged in non-destructive testing shall pass the test
according to TSG Z8001 or related standards and obtain corresponding
7.4 Metallographic inspection
Each batch of austenitic-ferritic duplex stainless steel pipe fittings shall undergo a metallographic inspection. Inspection method is according to GB/T 13305. The metallographic structure of pipe fittings in delivery state shall be austenite and ferrite. The austenite content shall be 40%~60%. For welded pipe fittings, the austenite content in the weld area is negotiated between the supplier and the purchaser.
7.5 Hydrostatic test
This Standard does not require a separate hydraulic test for pipe fittings. All pipe fittings shall be able to withstand the hydraulic test pressure required by the applicable piping code for seamless pipes with the same nominal size and c) The length is not more than 1/8 of the nominal diameter.
8.2 Before welding repair, defects shall be removed by cutting, shoveling or grinding. According to the material, carry out magnetic particle testing or penetration testing on the removed part, so as to ensure complete removal of defects.
8.3 During welding repair, welding consumables that match the base metal shall be selected. The welder who has obtained the corresponding welding
qualification shall perform welding in accordance with the welding procedure specification.
8.4 After welding repair, the repaired surface shall be trimmed by cutting or grinding. The trimmed part shall be smoothly transitioned to the pipe fitting surface. According to the material, perform magnetic particle testing or penetrant testing on the trimmed part, so as to ensure the repair quality. 8.5 Alloy steel, low-temperature steel and stainless steel pipe fittings shall be subjected to corresponding heat treatment after welding repair.
9 Surface protection and packaging
9.1 Unless otherwise specified, for pipe fittings of carbon steel, alloy steel and low temperature steel, anti-rust paint shall be applied to the outer surface (excluding welding groove). Stainless steel pipe fittings shall be pickled and passivated.
9.2 Before painting or passivation, the pipe fittings can be pretreated by shot blasting or cleaning. Keep the surface clean and free of scale, rust or other attachments.
9.3 Welding grooves shall be protected by suitable methods to prevent knocks. 9.4 Pipe fittings shall be packed separately according to different material levels. Take moisture-proof measures. Packing list shall be enclosed in the packing box.
10 Product quality certificate
For pipe fittings produced according to this Standard, a product quality certificate shall be provided in accordance with the provisions on the 5.1B certificate type in GB/T 18253-2000. The product quality certificate shall include at least the following contents:
a) Name and address of pipe fitting manufacturer;
NOTE: This appendix provides additional requirements with special regulations for design and procurement options. One or more of them can be selected when ordering. The details in the additional requirements are negotiated by the supplier and the purchaser. A.1 Heat treatment
A.1.1 Perform heat treatment to pipe fittings as required by the purchaser. A.1.2 For pipe fittings of austenitic stainless steel containing titanium and niobium elements, after solid-solution heat treatment, conduct stabilization heat treatment. The stabilization heat treatment system is within the temperature range of 815??C~870??C. According to the maximum thickness of the pipe fitting, the insulation shall be at least 5min/mm. Then cool in the furnace or cool in air out of the furnace.
It is not allowed to directly use bars to manufacture pipe fittings when there are provisions in the order sheet.
A.3 Welding repair
Welding repair of pipe fittings is not allowed when specified in the order. A.4 High temperature tensile test
Conduct high temperature tensile test on pipe fittings. The test method is according to GB/T 4338. The test temperature, qualification requirements shall be negotiated between the supplier and the purchaser.
A.5 Ultrasonic testing
Conduct ultrasonic testing for pipe fittings. Test according to NB/T 47013.3 or the specification specified by the purchaser. The timing of testing, testing ratio and qualification level are negotiated by both parties.
A.6 Corrosion test
A.6.1 Conduct corrosion test on austenitic stainless steel pipe fittings. The test is carried out according to method E in GB/T 4334 (test method for stainless B.2 The standard names of raw materials listed in Table B.1~Table B.4 are as follows:
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 713, Steel plates for boilers and pressure vessels
GB/T 1220, Stainless steel bars
GB/T 1221, Heat-resistant steel bars
GB/T 1591, High strength low alloy structural steels
GB/T 3077, Alloy structure steels
GB 3087, Seamless steel tubes for low and medium pressure boiler
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 3531, Steel plates for low temperature pressure vessels
GB/T 4237, Hot rolled stainless steel plate, sheet and strip
GB/T 4238, Heat-resisting steel plate, sheet and strip
GB 5310, Seamless steel tubes and pipes for high pressure boiler
GB 6479, Seamless steel tubes for high-pressure chemical fertilizer equipment GB/T 8163, Seamless steel pipes for liquid service
GB/T 9711, Petroleum and natural gas industries - Steel pipe for pipeline transportation systems
GB 9948, Seamless steel tubes for petroleum cracking
GB/T 12771, Welded stainless steel pipes for fluid transport
GB 13296, Seamless stainless steel tubes for boiler and heat exchanger
GB/T 14976, Seamless stainless steel pipes for fluid transport