Hi,
I am performing flange leakage study using CAESARII Peq method.
And my doubt is regarding the value of gasket diameter in CAESAR database.

For a 10",1500# flange; CAESAR suggests a gasket diameter of 289 mm.

Whereas, If I refer ASME B16.20, the dimensional standard for the gasket being used. For 10", 1500# and R54 gasket, Gasket diameter is 323.85 mm. And b0 is less than 1/4.

Can anybody letme know, Why is there A difference in diameters?