Pressure ratings can vary depending on the flange standard system, such as European, American, etc., like PN1.6, PN2.5, or CL150/PN2.0, etc. Some standards combine both. The pressure ratings differ to some extent due to the different applications of flanges; for instance, large stainless steel flanges are primarily used in chemical engineering for high-temperature pipelines, thus requiring high material pressure resistance.

Therefore, customers often request forged flanges, as the material's organizational density is enhanced through forging.