GB/T 12236-2025Steel swing check valve for petroleum, petrochemical and allied industries (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. This document supersedes GB/T 12236-2008 "Steel Swing Check Valves for Petroleum, Chemical and Related Industries", and is consistent with GB/T 12236- Compared to.2008, aside from structural adjustments and editorial changes, the main technical changes are as follows:

a) The applicable scope has been changed and weight requirements have been added (see Chapter 1, Chapter 1 of the.2008 edition);

b) The term and definition of "split-type swing check valve" have been added (see 3.1);

c) Added flanged swing check valves (full bore), pressure self-tightening seal swing check valves, and pressure self-tightening seal tilt-disc swing check valves. Typical structural diagrams of swing check valves, pressure self-tightening sealing Y-type swing check valves, and flange-connected split swing check valves. (See 4.2, 4.4~4.7);

d) The structural length of the flange-connected split swing check valve has been increased (see 5.2);

e) Increased technical requirements for flange connection ends (see 5.3.1);

f) Post-weld heat treatment requirements for the welding of the valve body to the end flange have been added (see 5.4.3);

g) An additional pound-class requirement has been added for the minimum inner diameter of the valve seat (see 5.4.5);

h) Requirements for valve lifting devices have been added (see 5.6);

i) The connection requirements between the valve body and the valve cover have been changed (see 5.7,

4.6 of the.2008 edition);

j) The requirements for the connecting studs between the valve body and the valve cover have been changed (see 5.8,

4.7 of the.2008 edition);

1 Scope

GB/T 12236-2025 is the Chinese national standard on steel swing check valve for petroleum, petrochemical and allied industries, in the field of fluid systems and general-purpose components. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 31 October 2025 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 May 2026. Classification: ICS 23.060.50, CCS J16. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This document specifies the structural type, technical requirements, materials, test methods, inspection rules, marking and protection, and packaging of steel swing check valves. Loading, transporting and storing. This document applies to nominal sizes DN50~DN1200 and nominal pressures PN16~PN400, and nominal sizes NPS2~NPS48 and... Nominal pressure Class 150~Class 2500, applicable temperature -29°C~550°C, applicable media include petroleum, chemical, natural gas and related products. Design, production and inspection of steel swing check valves with bolted valve covers, pressure self-tightening sealing valve covers, end flange connections or welding.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included. For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

GB/T 150.3 Pressure Vessels - Part

3 Design

GB/T 150.4 Pressure Vessels - Part

4 Manufacturing, Inspection and Acceptance

GB/T 196 Basic Dimensions of Ordinary Threads

GB/T 197 Tolerances for Standard Threads

GB/T 228.1 Metallic materials - Tensile testing - Part