Flowseal Metal Seat Valves - Pressure Temperature Ratings Chart

As temperature increases, the pressure retaining capability of materials decreases. The graph below illustrates the pressure/temperature ratings of the Flowseal ANSI Class 150, Class 300 and Class 600.

The heavy lines define the ratings of the carbon steel and the stainless steel valve body (or "shell") in conformance to ANSI B16.34. The shaded areas define the ratings of the metal sheet.

Seat ratings are based on differential pressure with the disc in the fully closed position.