v3.0.0 · Souders-Brown · droplet settling · API RP 12J (2024) basis · ASME VIII-1 screening
Process inputs
Vessel and service
Flow and conditions
scf at 14.696 psia, 60 °F; Sm3 at 15 °C; Nm3 at 0 °C
Natural gas typically 0.011 to 0.016 cP
Gravity section: 100 to 150 µm typical
Gas capacity (Souders-Brown K)
Horizontal 3 to 5; vertical 2 to 4
Liquid hold-up, surge and levels
Oil 1 to 3 min; foaming or heavy crude longer
Gas capacity uses the Souders-Brown allowable velocity on the gas flow area; liquid capacity provides hold-up (LLL to NLL) and surge (NLL to HLL) as separate bands. The tool sizes for both and reports which one governs. Default K values are typical published ranges; use the internals vendor's rated K for final design.
Sizing results
Vessel dimensions Aienginear
Gas capacity Souders-Brown
Liquid capacity and levels hold-up + surge
Design checks screening
Separator sketch
Schematic only, drawn to the calculated proportions. Not a fabrication drawing: nozzle locations, internals layout and supports need detailed engineering.
Nozzles, inlet momentum and type selection
Inlet momentum ρv²
Minimum nozzle sizes typical criteria
Droplet settling
Orientation wizard
Engineering advisor rule-based
Mechanical screening and cost
SA-516-70: 20,000 psi to 650 °F (ASME II-D)
1.0 full RT; 0.85 spot RT
Auto: max(1.10 × op, op + 25 psi)
ASME VIII Division 1 screening UG-27 / UG-32
Shell t = P·R / (S·E − 0.6P) + CA | 2:1 head t = P·D / (2S·E − 0.2P) + CA | Hydrotest ≈ 1.3 × MAWP (UG-99)
Screening only. Final thickness, MAWP, nozzle reinforcement, supports, wind and seismic loads, and impact testing must be designed to the current ASME BPVC Section VIII Division 1 (2025 edition) or your project's governing code by a qualified engineer. Cost is an order-of-magnitude indicator, not a budget estimate.
Compare cases
Save up to six cases, for example vertical against horizontal, or mesh pad against vane pack. Cases stay in this browser only.
Report and export
Everything is generated in your browser. Nothing you enter is uploaded or stored on a server.
Built-in self-test
Method summary
ρg = P·M / (Z·R·T), M = 28.965 × SG, R = 10.7316 psia·ft³/(lbmol·°R)
Vertical: diameter from the Souders-Brown area; height stacked from the bottom-to-LLL allowance, hold-up and surge heights, HLL-to-inlet clearance, inlet-to-demister disengagement (the larger of 0.5D and a fixed allowance), demister thickness and top space. If H/D exceeds the limit, the diameter is raised.
Horizontal: gas area above HLL from Souders-Brown; effective length is the largest of the hold-up length, the surge length and the droplet settling length (gas residence must exceed the time for the design droplet to fall through the gas space). Seam-to-seam length is the larger of Leff + D and 4/3 Leff. The diameter steps up until L/D is within the limit.
References: API RP 12J, 9th edition (2024), Process Design of Oil and Gas Separators and Scrubbers; GPSA Engineering Data Book Section 7; Souders and Brown (1934); Svrcek and Monnery (1993); Arnold and Stewart, Surface Production Operations; ASME BPVC Section VIII Division 1 (2025) and Section II Part D.
Powered by Aienginear.com · Engineering Made Smarter · Two-Phase Separator Sizing Calculator v3.0.0