Pipe Thickness Calculation as per ASME B31.3 | Pipe ...
S: Allowable Stress value of the Pipe Material (A 106-B) at Design Temperature (500° F). Refer to Table A-1 (or Table A-1M) of the ASME B31.3 (Fig. 3) for getting the value of the allowable stress. Travel in the horizontal (x) direction for allowable stress value and vertical (y) direction for pipe material, and the match point to get the value (refer to Fig. 3).