As per ASME B31.3 Section 304.1.3 "Straight Pipe Under External Pressure", to determine wall thickness and stiffening requirements for straight pipe under external pressure, the procedure outlined in ASME BPVC, Section VIII, Division 1, UG-28 through UG-30 shall be followed, using as the design length, L, the running centerline length between any two sections stiffened in accordance with UG-29.
Wall Thickness Calculation of Pipes and Tubes Under External Pressure
As per para. 304.1.3 Straight Pipe Under External Pressure by ASME B31.3 | Section VIII Division 1 — UG 28(c)(1) — Thickness of Shells and Tubes under External Pressure | Cylinders having Do/t values ≥ 10
Notes & References:
1. Calculation as per ASME B31.3 Para 304.1.3 & ASME BPVC Section VIII Division 1, UG-28(c)(1).
2. Applicable for cylinders having Do/t ≥ 10.
3. Factor A determined from ASME BPVC Section II Part-D, Table G (Geometric Chart for Components Under External Pressure).
4. Factor B determined from applicable material chart in ASME BPVC Section II Part-D, Subpart 3. Log-log interpolation used to match chart scale.
5. Modulus of Elasticity (E) values from ASME B31.3 / B31.4 tables.
6. L/Do capped at 50 per ASME code rules when exceeding 50.