ASME VIII-1, 2023 Edition
Registered in Alberta in June 2024 for 150 psi at 250 °F, with design MDMT and rated MDMT both set at −49 °F.
Compact 20 inch OD horizontal receiver built as a general utility vessel with 2:1 semi-ellipsoidal heads, SA-333 Gr 6 shell, SA-516-70 heads, and five set-in nozzles on saddles.
Reece Custom Manufacturing Inc. designed this vessel under APEGA Permit to Practice 15926. The calculation file is 02001500125250-49H1 Rev. 0, and the chamber summary limits hot corroded MAWP to 150 psi at 250 °F.
This example is positioned as a generic 20 inch horizontal receiver for shop-built utility service. The calc models a single chamber with internal pressure, external pressure, saddles, nozzle loads, hydrotest, and material toughness checks, without internals such as trays or packed sections.
The vessel is designed in Design Mode to ASME Section VIII, Division 1, 2023 Edition, with minimum thickness per UG-16(b) of 0.0938 in. RT1 marking applies to the shell and head circumferential seams, shop hydrotest is set to UG-99(b) at 1.3 times MAWP, and UG-22 load cases include vessel weight, saddles, wind, seismic, and nozzle external loads.
The 20 NPS SA-333 Gr 6 shell has a nominal wall of 0.375 in and a corroded design thickness of 0.2395 in governed by external pressure. Each 2:1 SE SA-516-70 head has required corroded thickness of 0.1987 in for internal pressure and 0.1753 in for external pressure, with 0.3125 in minimum after forming.
The shell is SA-333 Gr 6 welded seamless pipe, the heads are SA-516-70, and the flanged nozzles use A350 LF2 weld neck flanges with SA-193 B7 bolting. The vessel is mounted on two saddles with 55 in center-to-center spacing and uses a 0.125 in internal corrosion allowance on shell, heads, and nozzle necks.
The shell external-pressure case governs. The calc solves UG-28 and CS-2 for 15 psi external pressure and arrives at a required corroded wall of 0.1145 in, then adds 0.125 in corrosion allowance for a design thickness of 0.2395 in.
t_required (external) = 0.1145 in t_design = t_required + CA = 0.1145 + 0.125 = 0.2395 in
Using Appendix 1-1 with outside-diameter form, the shell internal-pressure requirement at 150 psi and 250 °F is about 0.213 in corroded. Because 0.213 in is less than 0.2395 in, the external-pressure case remains controlling.
t_required (internal) ≈ 0.213 in t_required (internal) < t_design (external) = 0.2395 in
For the 20 in OD SA-516-70 heads, Appendix 1-4(c) gives a corroded internal-pressure thickness of 0.1987 in. The adopted minimum thickness after forming is 0.3125 in, so the formed head has margin over both internal and external pressure requirements.
t_required, head (internal) = 0.1987 in t_min after forming = 0.3125 in
The 10 NPS set-in nozzle with reinforcement pad passes UG-37 area replacement. The calc reports required reinforcement area of about 0.875 in² and available area of about 3.87 in², so the opening is adequately reinforced.
A_required ≈ 0.875 in² A_available ≈ 3.87 in² > A_required
This receiver is a clear example of a compact registered pressure vessel that still includes external-pressure checks, RT1 weld marking, full hydrotest basis, cold-temperature toughness review, nozzle reinforcement, and saddle support calculations. It is a useful public reference for buyers comparing small horizontal receivers by code edition, CRN, material set, design conditions, and test basis.
Permit to Practice: 15926
Calc file reference: 02001500125250-49H1 Rev. 0
