An ASME class (150, 300, 600, 900, 1500, 2500) is a dimensionless rating designation. The allowable pressure depends on both the material group and the temperature.
A Class 150 A105 flange is rated 19.6 bar at 38 °C but only 13.8 bar at 200 °C.
Use the P-T ratings tool in this app to read and interpolate ratings for carbon steel and stainless groups.
