Does Autopipe include axial stress for ASME B31.1 and B31.3?
Both ASME B31.1 and B31.3 codes do not give explicit stress calculations for axial stress but for some cases e.g buried pipe, low modulus systems like FRP and high pressure systems it is recommended to consider axial stress. To include axial stress for all loadcases except pressure then use the option Tools model options /Results “include axial force” = checked. The sign is ignored when adding axial stress to the code stress calculation since this stress calculation is a gross longitudinal stress in the pipe. This is consistent with other pipe stress programs. Note: To include the axial stress due to the pressure analysis cases (P1 – P3) in the calculation of longitudinal pressure stress (may be significant for high pressure systems), under tools/code combinations/longitudinal pressure, option “Include rigorous pressure stress” = checked. By default this option is OFF.