ASME Section VIII Division 1, 2023 Edition, CRN V2315.2134, Alberta registration, August 2024
This 24 in. OD vertical pressure vessel is designed for 720 psi at 130 °F with a minimum design metal temperature of -20 °F and a rated MDMT of -22.4 °F. The vessel has a 120 in. straight shell, 2:1 ellipsoidal heads, a skirt support, and multiple process, instrument, and coupling connections arranged on the shell and heads.
Reece Custom Manufacturing designed and registered this vessel under APEGA Permit to Practice 15926. The registered calculation file is 024_0720_0125_+130_-20_V_1 Rev. 3, and the hydrotest basis in the calculation package includes a vertical shop hydrotest at 1,080 psi and a UG-99(b) vertical field hydrotest at 936 psi plus static head.
This example is a compact vertical process vessel with a dense nozzle layout and a skirt support. The registered design combines a 24 in. diameter shell, two ellipsoidal heads, flanged process nozzles from 2 NPS to 6 NPS, threaded couplings, threadolets, and a seismic check to NBC 2020.
The vessel is registered to ASME Section VIII Division 1, 2023 Edition for internal pressure service at 720 psi and 130 °F. The chamber summary reports a design MDMT of -20 °F, a rated MDMT of -22.4 °F, and no external pressure design case for the pressure boundary.
Loadings listed in the registered file include internal pressure, vessel and liquid weight, support loads, seismic, and hydrostatic test loading. Wind, snow, cyclic loading, impact loading, abnormal pressure, and thermal gradient loading are listed as not governing in the registered package.
The shell and heads are SA-516 Grade 70, and the MDMT path is based on UCS-66 with UCS-66.1 reduction applied to the main pressure parts. Several smaller nozzles and couplings are impact-test-exempt through the stress-ratio path noted in the registered file.
Required marking is RT4. The shell longitudinal seam is full radiography Type 1, and the circumferential seams are spot radiographed in line with the radiography summary reported in the calculation file.
The main shell is entered as SA-516 Grade 70, 24 in. OD, 120 in. long, with 0.625 in. nominal thickness, 0.125 in. corrosion allowance, and joint efficiency of 1.00. The required design thickness reported for the cylinder is 0.5518 in. under internal pressure.
Both ellipsoidal heads are also SA-516 Grade 70 with 0.625 in. nominal thickness and 2 in. straight flanges. The required design thickness is reported at 0.5378 in. for the top head and 0.5388 in. for the bottom head.
The vessel chamber summary reports 720 psi MAWP hot and corroded at 130 °F. The overall rated MDMT is -22.4 °F, limited by the flange-rated low-temperature capability of the smallest Class 300 flanged nozzles.
The new empty weight is 2,301 lb, the operating weight is 3,036 lb, and the new vertical test weight is 4,238 lb. Vessel capacity is reported as 232 US gal.
The shell and both heads are SA-516 Grade 70. The support skirt is SA-53 electric-resistance-welded pipe, 20 in. ID × 24 in. long × 0.375 in. nominal thickness.
Main process nozzles are SA-106 Grade B seamless pipe with SA-105N weld neck flanges. The registered nozzle schedule includes 6 NPS Sch 160, 4 NPS XXS, 3 NPS Sch 160 or XXS, and 2 NPS Sch 160 nozzle necks, all with Class 300 flanges.
Small connections include SA-105 threaded couplings and SA-105 threadolets. The calculation package identifies several of these small openings as exempt from reinforcement calculations under the small-opening rules used in the registered file, while still checking minimum neck thickness.
Corrosion allowance on the primary pressure parts is 0.125 in. Head-to-shell seams and shell seams are listed in the radiography summary, and the vessel is marked RT4 in the registered design package.
Inputs: P = 720 psi; S = 20,000 psi at 130 °F; E = 1.00; outside diameter = 24 in.; corrosion allowance = 0.125 in.
t = (P · R) / (S · E - 0.4P)
The registered thickness summary reports a required cylinder thickness of 0.5518 in. for the shell under internal pressure. With a 0.625 in. nominal shell and 0.125 in. corrosion allowance in the design package, the selected shell thickness meets the registered pressure basis.
Inputs: P = 720 psi; D = 24 in.; S = 20,000 psi; E = 1.00; corrosion allowance = 0.125 in.
K = 1 / 6 [2 + (D / 2h)^2]
t = (P · D · K) / (2SE - 0.2P) + CA
The top head calculation pages report a required design thickness of 0.5378 in. and the bottom head pages report 0.5388 in. The selected 0.625 in. nominal head thickness provides the registered pressure thickness plus corrosion allowance.
Inputs: Design MDMT = -20 °F; shell and heads in SA-516 Grade 70; nozzle flange low-temperature ratings reported in the pressure summary notes.
Rated MDMT = max(component governing MDMT)
The shell and heads are rated colder than the design MDMT through the UCS-66 path shown in the calculation package. The chamber rated MDMT is -22.4 °F because the 2 NPS Class 300 flange rating governs the final chamber rating.
Inputs: MAWP = 720 psi; shop hydrotest pressure entered by user = 1,080 psi; field test basis per UG-99(b) = 1.3 × design pressure.
P_test,field = 1.3 × 720 = 936 psi
The registered file reports a vertical shop hydrostatic test at 1,080 psi at 70 °F and a corroded vertical field hydrostatic test at 936 psi plus static head. The reported test summary shows all listed components within allowable test stress.
This case study shows a compact high-pressure vertical vessel with a dense nozzle schedule, low-temperature evaluation, hydrotest checks, and seismic reporting for Alberta service. It is a useful public example for buyers and engineers looking for real registered vessel data such as code edition, CRN, pressure rating, material selection, nozzle arrangement, and test basis.
Reece Custom Manufacturing, APEGA Permit to Practice 15926. Registered calculation reference: 024_0720_0125_+130_-20_V_1 Rev. 3. CRN V2315.2134. Registration date: August 13, 2024.