Input Data: Start up circulation flow of P‐ 6001 63.1 m3/hr Operating pressure 65 bar Operating Temperature 130 C Density 934.4 kg/m3 Viscosity 0.21 cP Number of orifice required 2 First Orifice Inlet pressure 65 bar Permanent Pressure Drop for multistage orifice 60 bar Nominal pipe diameter 4 in Inside pipe diameter 97.14 mm Vapor pressure in operating Temperature 2.7 bar Critical pressure 220 bar Critical temperature 374 bar Head loss in pipe 1.5 bar D‐6001 max operating pressure 2.9 bar Outlet pressure of orifices 4.4 bar Cl l ASME MFC 3M 1989 CALCULATION SHEET FOR MULTISTAGE RESTRICTION ORIFICE Calculaon: ASME MFC‐3M_1989 F=crical flow factor= dp/(Inlet pressure‐vapor pressure) should be lower than 0.7 for total dp=60.7 bar F= 0.963082 F for first orifice= 0.690209 <0.7 65 to 43 43 F for second orifice= 0.673575 <0.7 22 to 9 13 F for third orifice= 0.634921 <0.7 9 to 5 4 Calculaon for first orifice dp=43 bar >0.7 then multistage orifice should be selected
