How are the pressure levels of stainless steel flanges classified?

　　The pressure bearing function of materials has high requirements.

　　Therefore, customers often require forged flanges, as the forging of the materials increases the density of the arrangement and also enhances its ability to withstand pressure.

　　There are clear grade requirements for the compression resistance of large stainless steel flanges in domestic and international standards. Large stainless steel flanges are generally divided into PN6, PN10, PN16, PN25, PN40, etc. Among them, the most commonly used are PN10 and PN16.

　　For example, the design pressure of the flange of an internal pressure vessel with a safety valve should be determined based on the opening pressure of the 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 taken as 1.05-1.1 times the working pressure.

　　Given stainless steel flanges a working pressure of 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 more reasonable to select a maximum allowable working pressure of 0.9MPa (1.0MPa grade flange) for the container pipe flange 1C4 data at 50 degrees Celsius.