How do common slip-on flanges divide the pressure level?

　　The common slip-on flanges is used in different places, so the pressure level is different to a certain extent. For example, large stainless steel slip-on flanges is mainly used in high temperature pipeline of chemical engineering, so it has a high requirement for its material pressure performance.

　　Therefore, customers often require forged slip-on flanges, because the material is forged to improve the density of the organization, but also enhance its bearing capacity.

　　Large stainless steel slip-on flanges are generally divided into PN25, PN6, PN10, PN16, PN25, PN40 and so on. The two most commonly used are PN10 and PN16.

　　For example, the design pressure of the ANSI A182 F304 F316 Stainless Steel Slip On Flange of an internal pressure vessel with a relief valve should be determined according to the opening pressure of the relief valve. The design pressure is equal to or slightly greater than the opening pressure of the relief valve, and the opening pressure of the relief valve is 1.05-1.1 times of the working pressure.

　　Known operating pressure is 0.8 MPa, then the relief valve opening pressure can take 0.88 MPa, so the design pressure can take 0.9 MPa. Thus, it is reasonable to choose the maximum allowable working pressure of 0.9 MPa for the 1C4 material of the flange of the vessel tube at 50 degrees Celsius.