Flange standard system commonly used in China

At present, there are many application standards of pressure pipeline and its components in China, but they are not complete. Taking the pipe flange standard as an example, the commonly used standards include national standard (GB), machinery industry standard (JB), petrochemical industry standard (SH) and chemical industry standard (Hg). Each of these standards has its own temperature pressure gauge, sealing surface size and nozzle size, and the interchangeability between them is poor, and some of them can not even be used together. In order to apply these standards well, three ring flange introduces some commonly used pressure pipeline application standard systems in China.

1. Flange standard Hg of Ministry of chemical industry

2. Flange standard sh of Ministry of petrochemical

3. Flange standard JB of Mechanical Department

4. National flange standard GB

Matching problems of standard application system for pressure pipe flange:

a. There are many applicable standard systems for pressure pipelines, and some of them can not be used together. Some of them can be used together, but some problems should be paid attention to.

b. The same application standard system should be adopted for one device or several devices constructed at the same time, so as to avoid some errors caused by the coordination between different standard systems.

c. In engineering, it is often encountered that two or more sets of application standard systems are used in one device at the same time, or because the application standard of one set of standard system is not perfect, it needs the support of other systems. This requires the material engineer to know not only the relevant standard system, but also the standard coordination among various systems.

d. Pay attention to check the temperature pressure value of each standard.