Allowable Stresses of ASTM A105 in ASME B31.3

Forged flanges, forged fittings and other forgings made of ASTM A105 can be applied to process piping in accordance with ASME B31.3. The basic allowable stresses in tension for ASTM A105 at elevated temperatures are tabulated in Table A-1 below for design calculation. Allowable stresses in shear shall be 0.80 times the basic allowable stresses in tension, and allowable stresses in bearing shall be 1.60 times that value. Allowable stresses in compression shall be no greater than the basic allowable stresses in tension.

The ASTM A105 flanges can also be applied to high pressure piping. The high pressure is considered herein to be pressure in excess of that allowed by ASME B16.5 PN 420 [Class 2500] rating for the specified design temperature and material group. The allowable stresses in tension for ASTM A105 forgings for high pressure piping at elevated temperatures are tabulated in Table K-1 below.