method 1: SIZING FOR TWO-PHASE FLASHING OR NONFLASHING FLOW THROUGH A PRESSURE RELIEF VALVE. Saturation Temperature at PRV inlet (R) Saturation Pressure at PRV inlet (psia) specific volume of the two-phase system at the PRV vo= inlet (ft3/lb). specific volume evaluated at 90% of the PRV inlet v9= pressure (ft3/lb) pressure at the PRV inlet (psia). This is the PRV = set pressure (psig) plus the allowable overpressure (psi) plus atmospheric pressure. combined vapor/liquid required relieving Q = capacity (lb/hr). total backpressure (psia). Pa = To = relieving temperature (R ).
method 1: SIZING FOR TWO-PHASE FLASHING OR NONFLASHING FLOW THROUGH A PRESSURE RELIEF VALVE. Saturation Temperature at PRV inlet (R) Saturation Pressure at PRV inlet (psia) vo= specific volume of the two-phase system at the PRV inlet (ft3/lb). v9= specific volume evaluated at 90% of the PRV inlet pressure (ft3/lb) = pressure at the PRV inlet (psia). This is the PRV set pressure (psig) plus the allowable overpressure (psi) plus atmospheric pressure. Q = combined vapor/liquid required relieving capacity (lb/hr). Pa = total backpressure (psia). To = relieving temperature (R ).
Allied-Valve-Diers-Two-Phase-Flow-Required-Data.docx