API vs. ASME/ANSI Flanges with the same Dimensions

API vs. ASME/ANSI Flanges with the same Dimensions

Flange

Pressure Class Rating (psi) Nominal Size Range (inches)

ASME/ANSI B16.5 API 6A ASME/ANSI B16.5 API 6A1)

Weld neck

600 2000

1/2 - 24

113/16 - 11

900 3000

1500 5000

Blind and Threaded

600 2000 113/16 - 211/4

900 3000 113/16 - 203/4

1500 5000 113/16 - 11

2500 10000