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GB/T 21387-2025: Axial flow check valve for water supply system
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Std ID	Version	USD	Buy	Deliver [PDF] in	Title (Description)
GB/T 21387-2025	English	359	Add to Cart	4 days [Need to translate]	Axial flow check valve for water supply system
GB/T 21387-2008	English	229	Add to Cart	3 days [Need to translate]	Axial flow check valve

GB/T 21387-2025: Axial flow check valve for water supply system

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ICS 23.060.50 CCSJ16 National Standards of the People's Republic of China Replaces GB/T 21387-2008 Axial flow check valve for water supply system Published on 2025-10-31 Implemented on May 1, 2026 State Administration for Market Regulation The State Administration for Standardization issued a statement.

Table of contents

Preface III 1.Scope 1 2 Normative References 1 3.Terms and Definitions 2 4.Structural type and model designation 2 4.1 Structural Type 2 4.2 Model Numbering 4

5 Technical Requirements

5.1 Structural Length 5 5.2 Pressure-Temperature Ratings 5 5.3 Valve Body 5 5.4 Opening and Closing Components 6 5.5 Internal Connections and Fasteners 6 5.6 Materials 6 5.7 Shell strength 6 5.8 Sealing performance 6 5.9 Minimum opening pressure 6 5.10 Flow resistance coefficient 6 5.11 Minimum fully open flow rate 7 5.12 Maximum water hammer pressure rise 7 5.13 Fast Closing Time 7 5.14 Valve body material 7 5.15 Hygiene 7 5.16 Painting and Appearance 7 6.Test Methods 8. 6.1 Shell strength 8 6.2 Sealing performance 8 6.3 Minimum opening pressure 8 6.4 Flow resistance coefficient 8 6.5 Minimum fully open flow rate 8 6.6 Maximum water hammer pressure rise 8 6.7 Fast closing time 8 6.8 Valve Body Material 8 6.9 Hygiene 8 6.10 Painting and Appearance Inspection 9 7 Inspection Rules 9 7.1 Inspection Classification 9 7.2 Factory inspection 10 7.3 Type testing 10 7.4 Judgment Rule 10 8.Marking, Packaging, Transport and Storage 10. 8.1 Mark 10 8.2 Packaging 10 8.3 Transportation and Storage 10 Appendix A (Informative) Performance Test Methods for Axial Flow Check Valves 11 A.1 Test method for maximum water hammer pressure rise 11 A.2 Test method for rapid closing time 11 Figure 1.Ring-disc type split type 3 Figure 2.Ring-shaped integral type 3 Figure 3.Disc-shaped integral type 4 Figure 4.Schematic diagram of the minimum opening pressure test system. Figure A.1 Schematic diagram of the maximum water hammer pressure rise test system 11 Figure A.2 Schematic diagram of typical water hammer wave curve during pump shut-off process of axial flow check valve 12 Table 1.Structural Length 5 Table 2 Part Materials 6 Table 3.Inspection Items (9)

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 replaces GB/T 21387-2008 "Axial Flow Check Valves". Compared with GB/T 21387-2008, the only changes are structural adjustments and editing. Aside from the sexual alterations, the main technical changes are as follows. a) The scope of application has been changed (see Chapter 1, Chapter 1 of the.2008 edition); b) The term "axial flow check valve" and its definition (see Chapter 3 of the.2008 edition) have been deleted, and the term "maximum water hammer pressure rise" has been added. "Value", "Quick Closing Time", "Minimum Fully Opening Velocity", and "Minimum Opening Pressure" and their definitions (see Chapter 3); c) A model designation system has been added (see 4.2); d) The structural length has been changed (see Table 1,.2008 edition); e) A minimum wall thickness requirement has been added (see 5.3.4); f) Added requirements for "opening and closing components" (see 5.4); g) The "Materials" requirements have been changed (see 5.6, Chapter 6 of the.2008 edition); h) The "Sealing Performance" requirement has been changed (see 5.8, 5.11 in the.2008 edition); i) The "minimum opening pressure" requirement has been changed (see 5.9, 5.4 in the.2008 version); j) The requirement for "flow resistance coefficient" has been changed (see 5.10, 5.12 in the.2008 edition); k) The requirements for "valve disc", "limiting guide sleeve" and "spring" have been removed (see 5.5, 5.6, and 5.7 of the.2008 edition); l) Added requirements for "minimum fully open flow rate", "maximum water hammer pressure rise", "rapid closing time", "valve body material", and "hygiene" (see 5.11~). 5.15); m) The requirements for “Painting and Appearance” have been changed (see 5.16, 5.9 in the.2008 edition); n) Added tests for "minimum fully open flow rate", "maximum water hammer pressure rise", "rapid closing time", "valve body material", "hygiene", and "coating and appearance". Test methods (see 6.5~6.10); o) The "Supply Requirements" section has been removed (see 9.4 in the.2008 edition). Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents. This document was proposed by the China Machinery Industry Federation. This document is under the jurisdiction of the National Technical Committee on Valve Standardization (SAC/TC188). This document was drafted by. Shanghai Guanlong Valve Energy-Saving Equipment Co., Ltd., CNNC Suzhou Valve Technology Industry Co., Ltd., and Zigong New... Diper Valve Co., Ltd., Bonasway Valve Co., Ltd., Anhui Hongxing Valve Co., Ltd., Hangzhou Chunjiang Valve Co., Ltd. Zhongfa Holding (Group) Co., Ltd., Chengdu Chuanli Intelligent Fluid Equipment Co., Ltd., Anhui Fangxing Industrial Co., Ltd., Yuanda Valve Door Group Co., Ltd., Ningbo No.1 Machinery Valve Manufacturing Co., Ltd., Sichuan Gute Valve Manufacturing Co., Ltd., Shanghai Hang Technology Group Co., Ltd. Zhejiang Aodehua Technology Co., Ltd., Shanghai Yuanfa Smart Water Research Institute, Zhejiang Petrochemical Valve Co., Ltd., Jiangsu Suyuan Valve Machinery Limited Liability Company, Jiangsu Tenglong Petrochemical Machinery Co., Ltd., Guogong Holding Group Co., Ltd., Tianjin Karls Valve Co., Ltd., Shandong Yi Baitong Valve Co., Ltd., Shanghai Fenglei Valve Group Co., Ltd., Shanghai Outelai Valve Machinery Co., Ltd., Zhengfeng Valve Group Co., Ltd. Company, Tianjin Tanggu Watts Valve Co., Ltd., Zhejiang Kete Valve Co., Ltd., Suzhou Juhan Valve Co., Ltd., Beijing Aolister Investment Management Co., Ltd., Zhejiang Kaigong Fluid Equipment Co., Ltd., Zhejiang Longyu Valve Co., Ltd., Zhejiang Xinghe Intelligent Control Technology Co., Ltd. Qingdao Jindapeng Powder Technology Co., Ltd. The main drafters of this document are. Liu Fengnian, Zhao Jie, Yue Yang, Huang Linjie, Wang Donghui, Chen Yifei, Xie Ke, Chen Xing, Zhang Wei, Fang Chao, and Jiao Donghui. Zhou Zhenfeng, Li Jianfei, Xie Hongwen, Xu Yihai, Wang Aijie, Xiang Wei, Wang Yin, Dai Yiming, Yu Jinli, Ge Chunye, Wang Weijie, Lü Guoqin, Guo Jianwu Chen Tiejun, Zhu Fengyuan, Wang Zhanbo, Geng Lian, Yin Jiangwu, Liu Xiuming, Lin Hai, Cai Xutian, Xia Lida, Sun Peng. This document was first published in.2008, and this is its first revision. Axial flow check valve for water supply system

1 Scope

This document specifies the general requirements, technical requirements, test methods, inspection rules, marking, and packaging of axial flow check valves used in water supply systems. Loading, transporting and storing. This document applies to supplies with nominal sizes of DN50~DN2200 and nominal pressures of PN6~PN100, for media with temperatures not exceeding 65℃. Axial flow check valves are used in water systems.

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 1220 Stainless Steel Bars GB/T 1732 Test method for impact resistance of paint film GB/T 2100 General purpose corrosion-resistant steel castings GB/T 5210 Paints and varnishes - Pull-off adhesion test GB/T 6739 Paints and varnishes - Determination of film hardness using the pencil method GB/T 8923.1-2011 Visual assessment of surface cleanliness of steel surfaces before coating - Part 1.Uncoated steel surfaces Rust level and treatment level of steel surface and steel surface after complete removal of original coating. GB/T 9124.1 Steel pipe flanges - Part 1.PN series GB/T 9124.2 Steel pipe flanges - Part 2.Class series GB/T 9286 Paints and varnishes - Cross-cut test GB/T 9441 Metallographic Examination of Ductile Iron GB/T 9441-2021 Metallographic Examination of Ductile Iron GB/T 12224 General requirements for steel valves GB/T 12225 Technical Requirements for Copper Alloy Castings for General Valves GB/T 12226 Technical Specification for Gray Cast Iron Parts of General Valves GB/T 12227 Technical Specification for Ductile Iron Valves GB/T 12229 Technical Specification for Carbon Steel Castings of General Valves GB/T 12229-2025 Technical Specification for Carbon Steel Castings of General Valves GB/T 12230 Technical Requirements for Stainless Steel Castings for General Valves GB/T 12230-2023 Technical Requirements for Stainless Steel Castings for General Valves GB/T 13452.2 Determination of film thickness of paints and varnishes GB/T 13927 Pressure Testing of Industrial Valves GB/T 13927-2022 Pressure Testing of Industrial Valves GB/T 17219 Safety Evaluation Standard for Drinking Water Transmission and Distribution Equipment and Protective Materials ...