How to Classify Low, Medium and High Pressure Grades of Threaded Flanges

　　Low pressure pipeline: threaded flange nominal pressure not exceeding 2.5 (excluding) MPa

　　Medium pressure pipeline: threaded flange nominal pressure 2.5 (including) - 6.4 MPa

　　High pressure pipeline: threaded flange nominal pressure 10-100 MPa

　　Ultra-high pressure pipeline: threaded flange nominal pressure exceeds 100 MPa

　　Common flanges are generally Stainless Steel Threaded Flange, threaded flange are mainly used in different pressure levels of fluid equipment, so the pressure level is different, such as ASME A234 Sch10S RF Stainless Steel Threaded Flange are mainly used in chemical engineering high temperature corrosion resistant pipelines, so its material pressure and corrosion resistance are very high requirements.

　　Forging threaded flange is usually used for high pressure flange, because the material has been forged to improve the density of the structure, but also to enhance its bearing capacity. In domestic and international standards, there are clear requirements for the pressure resistance of carbon steel flanges and stainless steel flanges. The commonly used pressure grades of threaded flanges are PN2.5, PN6, PN10, PN16, PN25, PN40 and so on. The most commonly used are PN10 and PN16.