Socket flanges are used in different places, so the pressure level is different to a certain extent. For example, large stainless steel DIN Class300 Forged Carbon Steel Socket Flanges are mainly used in high temperature pipelines in chemical engineering, so the material pressure performance of socket flange is very high.
Therefore, customers often require forging socket flanges, because the material after forging increases the density of the organization, but also enhance its pressure bearing capacity.
In domestic and international standards, the pressure resistance of large stainless steel socket flanges has clear grade requirements. Large stainless steel socket flanges are generally divided into: PN25, PN6, PN10, PN16, PN25, PN40 and so on. The most commonly used are PN10 and PN16.
For example, the design pressure of socket flanges 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, while the opening pressure of the safety valve is 1.05-1.1 times of the working pressure.
Given that the working pressure is 0.8 MPa, the opening pressure of the safety valve can be 0.88 MPa, so the design pressure can be 0.9 MPa. In this way, it is reasonable to choose the material 1C4 of vessel socket flanges with the maximum allowable working pressure of 0.9 MPa at 50 degrees Celsius.