Standard No.:	GB/T 12236-2025
English Name:	Steel swing check valve for petroleum;petrochemical and allied industries
Chinese Name:	石油、化工及相关工业用钢制旋启式止回阀
Chinese Classification:	J16    Valve
Professional Classification:	GB    National Standard
ICS Classification:	23.060.50 23.060.50    Check valves 23.060.50
Source Content Issued by:	SAMR, SAC
Issued on:	2025-10-31
Implemented on:	2026-5-1
Status:	to be valid
Superseding:	GB/T 12236-2008 Steel swing check valve for petroleum petrochemical and allied industries
Target Language:	English
File Format:	PDF
Word Count:	13500 words
Translation Price(USD):	405.0
Delivery:	via email in 1~5 business day

GB/T 12236-2025 Steel swing check valve for petroleum;petrochemical and allied industries English, Anglais, Englisch, Inglés, えいご This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered. ICS 13.220.10 CCS H 57 National Standard of the People's Republic of China ‌GB/T 12236-2025 Replaces GB/T 12236-2008 Steel swing check valve for petroleum;petrochemical and allied industries 石油、化工及相关工业用钢制旋启式止回阀 Issue date: 2025-10-31 Implementation date: 2026-05-01 Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China the Standardization Administration of the People's Republic of China Contents Foreword 1 Scope 2 Normative References 3 Terms and Definitions 4 Structural Types 5 Technical Requirements 5.1 Pressure-Temperature Ratings 5.2 Face-to-Face Dimensions 5.3 Ends 5.4 Valve Body 5.5 Bonnet 5.6 Lifting Devices 5.8 Bolting Between Valve Body and Bonnet 5.9 Disc 5.10 Arm and Pin 5.11 Elastic Sealing Ring 5.12 Non-Destructive Testing 5.13 Fugitive Emission Testing 5.14 Pressure Testing 6 Materials 6.1 Valve Body and Bonnet 6.2 Seat 6.3 Disc 6.4 Arm, Bracket and Pin 6.5 Bolting Between Valve Body and Bonnet 6.6 Plug 6.7 Nameplate 6.8 Bypass Piping and Bypass Valve 6.9 Disc and Seat Sealing Faces 6.10 Gasket 6.11 Corrosion Resistance Requirements 7 Test Methods 7.1 General 7.2 Pressure Testing 7.3 Shell Wall Thickness Measurement 7.4 Sealing Face Hardness Measurement 7.5 Material Composition Analysis 7.6 Mechanical Property Testing of Valve Body Material 7.7 Valve Body Marking Inspection 7.8 Nameplate Content Inspection 7.9 Fugitive Emission Testing 7.10 Non-Destructive Testing 8 Inspection Rules 8.1 Factory Inspection 8.2 Type Test 9 Marking 10 Protection, Packaging, Transportation and Storage 11 Ordering Requirements Appendix A (Informative) Order Contract Data Sheet for Steel Swing Check Valves for Petroleum, Petrochemical and Related Industries 1 Scope This document specifies the structural types, technical requirements, materials, test methods, inspection rules, marking, corrosion protection, packaging, transportation, and storage for steel swing check valves. This document applies to the design, production, and inspection of steel swing check valves with nominal sizes DN50 to DN1200 and nominal pressures PN16 to PN400, or nominal sizes NPS2 to NPS48 and nominal pressures Class150 to Class2500, applicable temperature range -29°C to 550°C, applicable media include petroleum, chemical, natural gas and related products. The valves feature bolted bonnets, pressure-self-sealing bonnets, and flanged or welded end connections. 2 Normative References The provisions of the following documents constitute essential clauses of this document through normative references in the text. For dated references, only the version published on the cited date applies. For undated references, the latest version (including all amendments) applies. GB/T 150.3 Pressure vessels - Part 3: Design GB/T 150.4 Pressure vessels - Part 4: Manufacture, inspection and acceptance GB/T 196 Basic dimensions of general purpose metric screw threads GB/T 197 Tolerances of general purpose metric screw threads GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at ambient temperature GB/T 6175 Hexagon nuts, style 2 GB/T 9124 Steel pipe flanges (all parts) GB/T 12220 Industrial valves - Marking GB/T 12221 Metallic valves - Face-to-face dimensions GB/T 12224 Steel valves - General requirements GB/T 12228 Technical specification for carbon steel forgings for general purpose valves GB/T 12229 Technical specification for carbon steel castings for general purpose valves GB/T 12230 Technical specification for stainless steel castings for general purpose valves HG/T 20592 Steel pipe flanges (PN series) HG/T 20615 Steel pipe flanges (Class series) GB/T 26480 Valves - Inspection and testing GB/T 26481 Industrial valves - Fugitive emission testing GB/T 40079 Valve fugitive emission testing - Classification and qualification procedures JB/T 106 Marking and painting for valves NB/T 47013.2 Non-destructive testing of pressure equipment - Part 2: Radiographic testing NB/T 47013.3 Non-destructive testing of pressure equipment - Part 3: Ultrasonic testing NB/T 47013.4 Non-destructive testing of pressure equipment - Part 4: Magnetic particle testing NB/T 47013.5 Non-destructive testing of pressure equipment - Part 5: Penetrant testing SY/T 0599 Technical specification for sulfide stress cracking and stress corrosion cracking resistant metallic materials for natural gas surface facilities 3 Terms and Definitions The following terms and definitions apply to this document: 3.1 Split swing check valve A valve composed of left and right valve body parts. The valve body's flange adopts a gasket or gasket ring for sealing. The left and right valve bodies are connected with bolts, and the disc and seat sealing surfaces feature tapered structures. 4 Structural Types 4.1 The typical structural type of flanged swing check valve is shown in Figure 1. 5 Technical Requirements 5.1 Pressure-Temperature Ratings 5.1.1 The pressure-temperature ratings of the steel swing check valve shell shall comply with the provisions of GB/T 12224. 5.1.2 If the allowable pressure-temperature of the sealing elements or internal part materials used within the steel swing check valve shell is lower than the pressure-temperature rating of the shell material, the check valve shall use the pressure-temperature value of the sealing element or internal part material, and shall be marked on the nameplate. 5.2 Face-to-face Dimensions The face-to-face dimensions of flanged split swing check valves shall comply with Table 1. For other types of check valves, they shall comply with GB/T 12221 or as required in the order contract. Table 1 Face-to-face dimensions for flanged split swing check valves 5.3 Ends 5.3.1 Flanged ends shall comply with the provisions of GB/T 9124 (all parts), HG/T 20592, HG/T 20615, or as required in the order contract. 5.3.2 The dimensions of welded ends shall comply with the provisions of GB/T 12224, or as required in the order contract. 5.4 Valve Body 5.4.1 The valve body shall be manufactured by casting or forging. 5.4.2 The valve body with a cast flange connection end shall not be converted into a welding end by removing the flange end. 5.4.3 When the valve body is welded to the end flange, the end flange shall be a forged flange with a butt weld. The welding shall comply with the provisions of GB/T 150.4. The backing rings used for auxiliary welding shall be removed after welding. The post-weld heat treatment shall comply with the requirements specified in Table 2. ‌Table 2‌ Post-weld heat treatment for welded connection between valve body and end flange 5.4.6 The hole for connecting the valve body to the pipeline shall be round. The design should minimize the pressure loss and erosion impact of the fluid passing through the valve body. 5.4.7 Except for the following cases, the valve body shall adopt a separate seat ring structure: a) For valve bodies made of austenitic stainless steel material, the seat sealing surface may be directly machined on the valve body; b) Austenitic stainless steel or hardfacing material may be directly surfaced onto the valve body, with a surfaced layer thickness of no less than 1.6 mm after machining. 5.4.8 For Cr13-type materials, they shall be surfaced onto a separate seat ring, with a surfaced layer thickness of no less than 1.6 mm after machining. 5.4.9 The seat ring may be fixed to the valve body by threaded or welded connections. The threaded seat ring shall have a structure (such as grooves or protrusions) that facilitates installation and removal. The thread dimensions of the threaded seat shall comply with the provisions of GB/T 196. Spot welding may be used to prevent the seat