Industrial & Mechanical

Class Rating Explainer

See the maximum allowable working pressure for an ASME B16.5 flange or valve class at a given temperature.

Class

Temperature band

Max allowable pressure

19.65 bar

At temperature

-29 – 38 °C

Ratings shown for Group 1.1 carbon steel (A105/A106/A216 WCB) — other materials rate differently.

Class vs Schedule — what’s the difference?

Class is a pressure-temperature rating for flanges & valves (ASME B16.5) — NOT the same as Schedule, which is pipe wall thickness. The same Class rating holds less pressure as temperature rises.

Reference data — verify against manufacturer datasheet for critical/high-pressure applications.

Need the material, not just the numbers?

Send us your sizes, class or PN requirement and we’ll confirm stock and price.

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