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อัปเดต 2026-09-07
Pipe Wall Thickness
ASME B31.3 §304.1.2 Process Piping — pressure design thickness
Minimum process-pipe wall thickness for internal pressure per ASME B31.3, the corrosion-allowance and mill-tolerance build-up to the as-ordered nominal wall, and the Maximum Allowable Working Pressure a selected schedule can carry corroded.
คำนวณอย่างไร
Solves the diameter-basis Eq.3a for the pressure design thickness t (recomputing the Y coefficient from geometry via a 3-pass fixed-point iteration when t≥D/6, flagging the result outside Eq.3a's thin-wall validity), adds the corrosion/erosion/mechanical allowance c, grosses the sum up for the ASME B36.10M seamless mill under-tolerance to get the as-ordered wall, and rearranges the same equation to back-solve MAWP at a chosen schedule's corroded wall.
สมการ
Pressure Design Thickness (Eq. 3a)
ASME B31.3 §304.1.2, diameter basis; valid for t<D/6 (Y from Table 304.1.1, e.g. 0.4 for ferritic/austenitic ≤482°C).
Minimum Required & Ordered Thickness
§304.1.1; c = corrosion + erosion + mechanical allowance; default ASME B36.10M seamless mill under-tolerance 12.5%.
Maximum Allowable Working Pressure
t_a = t_nominal − c (corroded wall, no mill tolerance applied); algebraic rearrangement of Eq.3a for P.