How to divide the pressure level of socket flange

　　Common socket flange is used in different places, so the pressure rating is different to some extent. For example, large stainless steel socket flange is mainly used in chemical engineering high temperature resistant pipeline, so it has high requirements for its material pressure performance.

　　In the domestic and international standards, there are clear requirements for the compression resistance of DIN 304 Stainless Steel Socket Flange. Large stainless steel socket flange is generally divided into PN25, pn6, PN10, PN16, PN25, PN40, etc. The most commonly used are PN10 and PN16.

　　For example, the design pressure of socket flange of internal pressure vessel with safety valve should be determined according to the opening pressure of safety valve. The design pressure is equal to or slightly greater than the opening pressure of the safety valve, and the opening pressure of the safety valve is 1.05 ~ 1.1 times of the working pressure.

　　Given that the working pressure is 0.8MPa, the opening pressure of the safety valve can be taken as 0.88mpa, so the design pressure can be taken as 0.9mpa. In this way, it is reasonable to select the maximum allowable working pressure of 1C4 at 50 ℃.