STEEL | FITTINGS | FLANGES | FLANGES ansi b16.5  | Temperature-Pressure Ratings

Carbon steel pipe flanges to ANSI B16.5 (BS.1560)
Forgings to ASTM A105 – not recommended for prolonged use above 427°C
Forgings to ASTM A350-LF2 – not to be used above 343°C
Forgings to ASTM A105 – not recommended for prolonged use above 427°C
Forgings to ASTM A350-LF2 – not to be used above 423°C

Flanges above DN600 are not included in ANSI B16.5 standard and the class designations in these large diameters do not imply specific temperature/pressure ratings.

T = temperature in °C  |  PN20 = Class 150 |  PN50 = Class 300  |  PN100 = Class 600  |  PN150 = Class 900  |  PN250 = Class 1500  |  PN420 = Class 2500  |  Maximum working pressure in kpa/pn (pressure numbers)