ASME B16.5 1974

JPGriffin-

In the 1965 edition, many materials, CS through 9Cr were lumped together up to 650°F for their flange ratings. For 300# flanges, the ratings ranged between 720 psi at 100°F to 515 psi at 650°F and on to 85 psi at 1000°F.

In my 1977 edition, A181-1 material is placed into material group 1.4 which ranges from 620 psi at 100°F 450 psi at 650°F and on up to 50 psi at 1000°F.

Let me know what your temperature range is and I can fill in the blanks.

jt