Path: Home > GB/T > Page725 > GB/T 12221-2025

Price & Delivery

US$999.00 · In stock · Download in 9 seconds
GB/T 12221-2025: Metal valves - Face to face, end to end, centre to face and centre to end dimensions
Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure
Status: Valid

Std ID	Version	USD	Buy	Deliver [PDF] in	Title (Description)
GB/T 12221-2025	English	999	Add to Cart	7 days [Need to translate]	Metal valves - Face to face, end to end, centre to face and centre to end dimensions
GB/T 12221-2005	English	85	Add to Cart	0--9 seconds. Auto-delivery	Metal valves -- Face to face, end to end, center to face and center to end dimensions
GB/T 12221-1989	English	639	Add to Cart	5 days [Need to translate]	Metal valves for use in flanged pipe systems--Face-to-face and centre-to-face dimensions

GB/T 12221-2025: Metal valves - Face to face, end to end, centre to face and centre to end dimensions

---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
ICS 23.060.01 CCSJ16 National Standards of the People's Republic of China Replaces GB/T 12221-2005 Metal valve structure length center-to-face dimensions (MOD) 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 1 4.Structural form and dimensions 1 Appendix A (Informative) This document corresponds to the structure numbering in ISO 5752.2021.40 Appendix B (Informative) Correspondence between Nominal Size DN and NPS 41 Appendix C (Normative) Additional Length of Valves with Ring-Connected Flanges 42 Figure 1.Length of straight-through valve structure 2 Figure 2.Length of angle valve structure 2 Figure 3.Parallelism and perpendicularity tolerances. Figure C.1 Valve with ring-connected flange 42 Table 1.Basic Series of Flange Connection Structure Lengths (1~24) 4 Table 2 Basic Series of Flange Connection Structure Lengths (25~71) 6 Table 3 Basic Series of Flange Connection Structure Lengths (91~132) 8 Table 4.Structural Length of Flange-Connected Gate Valves (PN Series) 10 Table 5.Structural Length of Flange-Connected Gate Valves (Class Series) 11 Table 6.Structural Length of Flange-Connected Butterfly Valves (PN Series) 12 Table 7.Structural Length of Flange-Connected Butterfly Valves (Class Series) 13 Table 8.Structural Lengths of Flange-Connected Ball Valves and Plug Valves (PN Series) 14 Table 9.Structural Length of Flange-Connected Ball Valves and Plug Valves (Class Series) 16 Table 10.Flanged Diaphragm Valve Structure Length 17 Table 11 Structural Length of Flange-Connected Straight-Through Gate Valve (PN Series) 17 Table 12 Structural Length of Flange-Connected Straight-Through Gate Valve (Class Series) 18 Table 13 Structural Lengths of Flanged Angle Gate Valves and Lift Check Valves (PN Series) 19 Table 14 Structural Length of Flanged Angle Gate Valves and Lift Check Valves (Class Series) 20 Table 15 Structural Length of Flange-Connected Straight-Through Check Valve (PN Series) 21 Table 16 Structural Length of Flange-Connected Straight-Through Check Valves (Class Series) 23 Table 17 Flange and Wafer Connection Butterfly Check Valves (Class Series) 25 Table 18 Structural length of flanged copper alloy gate valves, globe valves, and check valves (25 mm) Table 19 Flange Connection Valve Structural Length Tolerance 26 Table 20 Tolerances for Parallelism or Perpendicularity of Flange-Connected Valve Structure Length 26 Table 21 Basic Series of Welded End Straight-Through Valve Structure Length 27 Table 22 Basic Series Length of Welded End Angle Valve Structure 28 Table 23 Welded-end gate valve structural length 29 Table 24 Welded End Ball Valve Structure Length 30 Table 25 Welded End Plug Valve Structural Length 31 Table 26 Structural Length of Welded End Straight-Through Gate Valves, Throttling Valves, and Check Valves (32mm) Table 27 Structural Length of Welded Angle Type Gate Valves, Throttling Valves, and Check Valves (33mm) Table 28 Welded End Valve Structural Length Tolerance 33 Table 29 Basic Series Length of Clamp Connection Structure 34 Table 30 Structure length of wafer-type butterfly valve 35 Table 31 Structural Length of Wafer-Type Butterfly Check Valve (PN Series) 36 Table 32 Structural Length of Wafer-Type Butterfly Check Valve (Class Series) 37 Table 33.Structure length of wafer-type swing check valve (38 mm) Table 34.Structure length of clamp-on lift check valve (38 mm) Table 35 Length Tolerance of Wafer Connection Valve Structure 39 Table A.1 Comparison of this document's structural number with ISO 5752.2021 40 Table B.1 Correspondence between Nominal Size DN and NPS 41 Table C.1 Additional Length (X) 43

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 12221-2005 "Structural Length of Metal Valves". Compared with GB/T 12221-2005, the only changes are structural adjustments. Aside from editorial changes, the main technical changes are as follows. a) The range has been changed and the pound size has been added (see Chapter 1, Chapter 1 of the.2005 edition); b) The term "wafer valve" and its definition have been deleted, and the terms "nominal size" and "nominal pressure" and their definitions have been added (see section 3). Chapter 3 (2005 edition); c) The structural form and dimensional requirements for the additional length of valves with annular gasket sealing flanges have been increased (see 4.1.2); d) The structural length requirements for flanged valve connections have been changed, and parallelism and perpendicularity tolerance requirements have been added (see 4.2,.2005). Version 4.3); e) The structural length requirement for valves with internal thread connections has been removed (see 4.3.5 in the.2005 edition); f) The structural length requirement for valves with external thread connections has been removed (see 4.3.6 in the.2005 edition); g) The structural length requirement for wafer-type knife gate valves has been removed (see 4.3.8 in the.2005 edition); h) Additional length requirements have been added for valves with ring-connected flanges (see Appendix C). This document is modified to adopt ISO 5752.2021 "Metallic valves for flanged piping systems - structural length". This document has undergone significant structural adjustments compared to ISO 5752.2021.A table comparing the structural numbering changes between the two documents is provided. See Appendix A. The technical differences between this document and ISO 5752.2021, and the reasons therefor, are as follows. a) The scope has been changed (see Chapter 1) to meet the needs of practical applications in my country; b) The structural diagrams for PN and Class 1 flanged valves (see Chapter 4 of ISO 5752.2021) have been removed to meet the requirements of my country's actual situation. The need in practical applications; c) The clause supplementing Table 1 has been changed to a note (see 4.2.2, paragraph 2 of Chapter 4, ISO 5752.2021) to meet the requirements. Requirements of GB/T 1.1; d) The structural length requirement for flanged straight-through gate valves with a nominal size greater than DN600 has been removed (see Chapter 4 of ISO 5752.2021). Tables 11 and 12) are used to meet the needs of practical applications in my country. e) The length requirements for welded valve structures have been increased (see 4.3) to meet the needs of practical applications in my country; f) The length requirements for clamp-on valve structures have been increased (see 4.4) to meet the needs of practical applications in my country; g) The basic series designation 109 for the structural length of Class-A wafer-type butterfly valves has been removed (see Chapter 4 of ISO 5752.2021). Table 7) is used to meet the needs of practical applications in my country; h) The supplementary notes to Tables 17 and 18 have been amended to table notes (see Tables 31 and 32, Chapter 4, Section 3 of ISO 5752.2021). (segment), to meet the requirements of GB/T 1.1. The following editorial changes have been made to this document. ---To align with existing standards, the standard name has been changed to "Structural Length of Metal Valves"; ---Added a footnote regarding the priority selection of basic series valves for flanged connections (see Chapter 4, Table 8, Table 11, and Table 12); ---The informative appendix on the source of basic series dimensions has been removed (see Annex C of ISO 5752.2021). 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. Hefei General Machinery Research Institute Co., Ltd., Hefei General Electromechanical Products Testing Institute Co., Ltd., and CNNC Suzhou Valve Technology Co., Ltd. Jishi Industrial Co., Ltd., Dushanzi Petrochemical Branch of China National Petroleum Corporation, and the 71st Research Institute of China State Shipbuilding Corporation The Ninth Research Institute, Anhui Tongdu Fluid Technology Co., Ltd., Zhejiang Petrochemical Valve Co., Ltd., Jiangsu Suyuan Valve Machinery Co., Ltd., Chengdu Chenggao Valve Co., Ltd., Hangzhou Chunjiang Valve Co., Ltd., Chaoda Valve Group Co., Ltd., Yuanda Valve Group Co., Ltd. Anhui Baihu Valve Factory Co., Ltd., Xuanda Industrial Group Co., Ltd., Shenjiang Valve Co., Ltd., and Taigang Alloy (Zhongshan) Co., Ltd. Company, Liangu Valve Group Co., Ltd., Sichuan Jingkong Valve Manufacturing Co., Ltd., Shanghai Biaoyi Valve Co., Ltd., Shanghai Ya'ao Valve Co., Ltd. Limited Liability Company, Beijing Valve General Factory Co., Ltd., Guogong Holding Group Co., Ltd., Lanzhou High Pressure Valve Co., Ltd., Zhejiang Linuo Fluid Control Technology Co., Ltd., Zhejiang Bell Control Valve Co., Ltd., Wuxi Skaur Automatic Control Equipment Co., Ltd., and Junpin Group Co., Ltd. Limited Liability Company, Wuxi Baoniu Valve Industry Co., Ltd., Shanghai Special Equipment Supervision and Inspection Technology Research Institute, Yancheng Aokaimingtong Valve Co., Ltd. Jiangsu Tenglong Petrochemical Machinery Co., Ltd., Shandong Weima Fluid Control System Co., Ltd., Yangquan Valve Co., Ltd., Beize Valve Group Limited Liability Company, Zhejiang Aodehua Technology Co., Ltd., Hubei Taihe Petrochemical Equipment Co., Ltd., Hubei Hongcheng General Machinery Co., Ltd. Shandong Yibaitong Valve Co., Ltd., Zhejiang Diai Intelligent Control Technology Co., Ltd., Zhejiang Deca Control Valve & Instrument Co., Ltd., Ningbo Huide Fengtong Copper Industry Co., Ltd., Sichuan Zhongyou Leyi Energy Equipment Manufacturing Co., Ltd., Shandong Tianli Machinery Casting Co., Ltd., and Kaitai Valve (Group) Co., Ltd., Gongnai Valve Co., Ltd., Zhejiang Moenda Valve Co., Ltd., Ouming Valve Group Co., Ltd., Taizhou Tonghe Fluid Control Co., Ltd., Zhejiang Lianda Valve Co., Ltd., Zhejiang Yufeng Machinery Co., Ltd., Jiangsu Jiangheng Valve Co., Ltd., Jingmen Meizhong American Valve Co., Ltd., Zhejiang Zhanfan Industrial Co., Ltd., Zhejiang Hengtong Valve Co., Ltd., Huaying Valve Co., Ltd., Zhejiang Chenggao Valve Co., Ltd. Limited Liability Company, Wenzhou Borui Valve Repair Service Co., Ltd., Sichuan Suke Fluid Control Equipment Co., Ltd., Taizhou Xingnuo Technology Co., Ltd. Limited Company. The main drafters of this document are. Wang Xiaojun, Hu Chunyan, Liu Ping, Lu Jun, Wang Cong, Pang Yunhua, Huang Jiaqiao, Han Zhengdong, Zeng Heyou, Wu Lei, and Chai Lu. Ye Jianzhong, Dong Ruipeng, Huang Jie, Ye Qunli, Ye Jijun, Sun Zhibiao, Zhang Peng, Qian Yanlin, Huang Zhimin, Zhan Kaifeng, Chen Jinbiao, Jing Dongyang, Hao Hongda Wu Yefei, Lin Tong, Da Rongsheng, Chen Xianling, Bian Hongfei, Chen Yi, Wang Xin, Dai Yiming, Liu Zhiwei, Han Xiaojun, Shao Liting, Zheng Lin, Zhang Wenzhong Wang Hongyun, Li Peng, Ding Chunlan, Kang Kang, Feng Zhenhua, Gu Changming, Yang Zhisen, Zhu Jingjing, Xu Hongxing, Tan Guiyuan, Li Jin, Zhou Jian, Chen Haifeng Ye Zhonghua, Xie Tahong, Ying Quan, Mao Liguo, Ke Xiaozhen, Hong Jinyao, Gou Huichao, Yao Xianli, Chen Changhua, Wu Rende. The release history of this document and the document it replaces is as follows. ---This document was first published in 1989 as GB/T 12221-1989; ---In the first revision in.2005, it was incorporated into GB/T 15188.1-1994 "Structural Length of Valves - Butt-Welded Connection Valves". GB/T 15188.2-1994 "Structural Length of Valves - Wafer Connection Valves", GB/T 15188.3-1994 "Structural Length of Valves" "Valves with Internal Thread Connections" and GB/T 15188.4-1994 "Valves with External Thread Connections" content; ---This is the second revision. Metal valve structure length

1 Scope

This document specifies the structural length and tolerances for metal valves. This document applies to nominal sizes DN8~DN4000 and nominal pressures PN2.5~PN400 or nominal sizes NPS⅟~NPS160. And flanged, welded, and wafer-type metal valves with nominal pressure Class 125~Class 2500 (valve types include. gate valves, throttle valves, etc.) Design, production and inspection of check valves, ball valves, butterfly valves, plug valves, diaphragm valves and check valves. Note. The correspondence between nominal size DN and NPS is shown in Appendix B.

2 Normative references

This document has no normative references.

3 Terms and Definitions

The following terms and definitions apply to this document. 3.1 nominal size DN/NPS Size designations for piping system components using a combination of letters and numbers, consisting of the letters DN or NPS followed by a dimensionless integer. composition. Note 1.This dimensionless number is indirectly related to the characteristic dimensions of the end connector, such as the bore or outer diameter [in millimeters (mm) or inches (in)]. Note 2.Unless otherwise specified in the relevant standards, the dimensionless numbers following DN or NPS do not represent measured values and cannot be used for calculations. 3.2 nominal pressure PN/Class The identifier, consisting of a combination of letters and numbers, related to the mechanical properties and dimensional characteristics of piping system components, is either PN or Class and followed by a suffix. It consists of dimensionless numbers. Note 1.Pipe components with the same PN or Class and nominal size (DN or NPS) values have the same connection dimensions as the flanges they mate with. Note 2.The maximum permissible working pressure of a piping component depends on the PN or Class number of the piping component, the material, the component design, and the maximum permissible operating temperature. Degree, etc. 3.3 The distance between the two end faces perpendicular to the axis at the end of the valve body channel. 3.4 The distance between the axis of one end face of the valve body channel perpendicular to the axis and the axis of the other end face. 4.Structural form and dimensions 4.1 Structural Form 4.1.1 Except for valves with annular gasket sealing flanges, the structural length of straight-through valves is shown in Figure 1, and the structural length of angle valves is shown in Figure 2. ...