GB/T 12241-2021Safety valves - General requirements (English PDF)

4.1.3.2 of Edition 2005);

h) Changed the minimum requirements for springs and divided into "minimum

requirements for helical compression springs" and "minimum requirements for

disc springs" (see 5.3 of this Edition, 4.1.4 of Edition 2005);

i) Deleted the safety valve material requirements (see 4.1.5 of Edition 2005);

j) Changed the general requirements of exit-factory test (see 6.2 of this Edition, 5.1.2

of Edition 2005);

k) Changed the adjustment requirements for cold differential test pressure (see 6.5

of this Edition, 5.1.5 of Edition 2005);

l) Changed the requirements for operating performance and discharge capacity test

(see Chapter 7 of this Edition, 5.2 of Edition 2005);

m) Deleted the requirements of "quality assurance system, installation of safety

valves, adjustment, maintenance and repair of safety valves" (see Chapter 9~11

of Edition 2005).

This Standard uses redrafting method to modify and adopt ISO 4126-1.2013 (including

Amendment in 2016) "Safety devices for protection against excessive pressure - Part 1.

Safety valves".

Compared with ISO 4126-1.2013 (including Amendment in 2016), there are some

structural adjustments in this Standard. The specific chapter numbers are as follows.

a) The content of 7.2.4 in ISO4126-1.2013 is 7.2.3 in this Standard.

b) The note in Figure 1 of ISO 4126-1.2013 is adjusted to 5.2.2 of this Standard.

There are technical differences between this Standard and ISO 4126-1.2013 (including

Amendment in 2016). These differences and their reasons are as follows.

a) Regarding normative references, this Standard has made adjustments with

technical differences to adapt to China's technical conditions and meet the needs

of China's application. The adjustment is concentrated in Chapter 2 "Normative

references". The specific adjustments are as follows.

- Use GB/T 36588 that is modified by adopting the international standard to

replace ISO 4126-7;

- Added GB/T 1239.2, GB/T 7306 (all parts), GB/T 9124 (all parts), GB/T 12224,

GB/T 12716, GB/T 15530.1, GB/T 15530.8, GB/T 17241.6, GB/T 17241.7, GB/T

23934, JB/T 2768, JB/T 2769 appear in the text.

b) Deleted the terms and definitions of "safety valve with power assist" and "safety

valve with supplementary load" not used in the text.

c) Added the requirements of 5.2.1 end connection type to meet the needs of China

in practical applications.

d) Added specific requirements for pressure-temperature ratings in 5.4 to meet the

needs of China in practical applications.

e) Deleted the test equipment requirements in 7.2.3 of ISO 4126-1.2013, because the

corresponding provisions have been made in GB/T 12242.

This Standard made the following editorial modifications.

a) Changed the standard name from "Safety devices for protection against excessive

pressure - Part 1.Safety valves" to "Safety valves - General requirements" that is

unified with GB/T 12241-2005.

b) Added bibliography to facilitate China's needs in practical applications.

This Standard was proposed by China Machinery Industry Federation.

This Standard shall be under the jurisdiction of National Technical Committee on Safety

Pressure Relief Device of Standardization Administration of China (SAC/TC 503).

The drafting organizations of this Standard. Shanghai Kite Valve Manufacturing Co.,

Ltd., Hefei General Machinery Research Institute Co., Ltd., Shanghai Valve Factory

Co., Ltd., Yongyi Valve Group Co., Ltd., Tianzheng Valve Co., Ltd., Yangzhong Valve

Factory Co., Ltd., Beijing Aerospace Petrochemical Technology Equipment

Engineering Co., Ltd., Wuhan Boiler Group Valve Co., Ltd., Chengde High and

Medium Pressure Valves and Fittings Group Co., Ltd., Jiangsu Suyan Valve Machinery

Co., Ltd., Shanghai Hugong Valve Factory (Group) Co., Ltd., Henan Gaoshan Valve

Co., Ltd., Zhejiang Chaochao Safety Valve Manufacturing Co., Ltd. Company, Xuzhou

Bafang Safety Equipment Co., Ltd., Wujiang Dongwu Machinery Co., Ltd., Keke

Group Co., Ltd., Wuhan Huake Energy Environmental Technology Co., Ltd., Kairuite

Valve Co., Ltd., Lianggong Valve Group Co., Ltd.

Main drafters of this Standard. Zhao Nanping, Wang Deping, Wang Xiaojun, Wang

Qiulin, Gan Aigen, Zhang Junce, Chen Jinlong, Wang Xuebin, Zhang Na, Zhan Yongfu,

Han Zhenghai, Yang Xiongjun, Yang Quanqing, Ding Chaochao, Shu Yuan, Zi

Xiaofeng, Wang Haizhuang, Hu Liangyin, Zhang Chuanhu, Peng Yu Lin, Jiang

Zhendong.

Versions of standard substituted by this Standard are.

- GB/T 12241-1989, GB/T 12241-2005.

Safety valves - General requirements