Introduction of nominal pressure characteristics of high pressure special shaped flange

The so-called high-pressure special-shaped flange with nominal pressure of pno.6mpa refers to the flange with such a specific size. The flange is made of 16MnR, and its maximum allowable operating pressure is 0.6MPa at 200 ℃. If the pn0.6mpa flange is used at a temperature higher than 200 ℃, its maximum operating pressure will be 0.6MPa lower than its nominal pressure. On the contrary, if it is used under the condition of lower than 200 ℃, the maximum working pressure is still determined at 200 ℃.

If the material of the flange is changed to Q235-A, the mechanical properties of Q235-A steel are worse than 16MnR. The maximum allowable operating pressure of the flange with nominal pressure of pn0.6mpa will be lower than its nominal pressure even when it is operated at 200 ℃. On the contrary, if the material of flange is changed from 16MnR to 15MnVR, because the mechanical performance of 15MnVR is better than 16MnR, the maximum allowable operating pressure of the flange with nominal pressure of pn0.6mpa will be higher than its nominal pressure when operating at 200 ℃.

The maximum allowable operating pressure of large high-pressure special-shaped flange depends on the operating temperature and material of the flange. The flange materials specified in the pressure vessel flange standard are low carbon steel (Q235-A, 20g, etc.) and ordinary low steel (16Mn, 16MnR, 15MnVR, etc.), and the conversion relationship between their nominal pressure and maximum allowable working pressure at different temperatures. The operating temperature and design pressure given in the design conditions can be converted into the nominal pressure required by the flange standard.