convalveEstimated air flow through given control valveunits1Gasair2Valve flow coefficient Cv (English)503Pressure upstreambarg34Pressure downstreambarg0.655Critical flow factor (assumed)16Gas specific gravity1.07Flowing temperaturedeg K2908Kind of flow (subcritical / choked)choked (1)9Volumetric flow thru valvestd m3/h302810Volumetric flowstd m3/s0.84NoteAir velocity 4" down pipem/s102approx P in the 4" down pipebar0.65(physical+equiv length ~ 60 m)velocity in 4" down pipeMach0.32(1)If flow is not choked, formula for volumetric flow is different, seeMasoneilan's "handbook of control valve sizing" as an example.