This guide covers the step-by-step procedure for calculating pipe wall thickness per ASME B31.3 Process Piping code. It explains the pressure design formula (t = PD/2(SE+PY)), accounts for mill under-tolerance (12.5%), and details how to add mechanical allowances (corrosion/erosion). The article solves a common engineering conflict: optimizing pipe schedules when high corrosion allowances threaten to increase project costs.
