Valve Pressure Class Selection
How industrial buyers should interpret Class, PN and PSI ratings before selecting a valve.
Pressure Class Is Not a Single Pressure Number
ASME pressure classes are tied to material group and temperature. A Class 600 valve does not have one fixed allowable pressure for every material and operating temperature. Check the governing standard and pressure-temperature table.
Buyer Checks
- Design pressure
- Design temperature
- Valve body material
- Applicable valve standard
- Flange / end-connection rating
- Transient or upset conditions