B31.8 Appendix R + API 1156 + 49 CFR Repair Criteria
Combined dent strain assessment per ASME B31.8 Appendix R. Plain (smooth) dent off-weld with strain ≤ 6% is acceptable; dents on welds, with metal loss, or above 6% strain trigger repair per 49 CFR 192.711 / 195.422.
Pipe
in
in
psig
Dent Geometry
%OD
in
in
Dent Type
If yes → App R does not apply; use API 579 Part 12.
📚 Theory
B31.8 App R derivation, parabolic-fit assumption, 6% limit basis, repair vs monitoring criteria.