psv pressure safety valve sizing calculation rev 01 xls

STD CALCULATION FOR PSV SIZING

Self Chk:________Date:________

Chkd:________ Date:_______

Apprvd:________Date:_______

PRESSURE SAFETY VALVE SIZING CALCULATIONSVAPOUR OR GAS RELIEF

22-Apr-23

Client:Job No:Project:

Tag No:Location:

PROCESS DATAVapour or Gas ReliefFluidRelieving ScenarioVessel Design CodeMass Flow , W kg/h 5400 11905 lb/hr.Gas Molecular Weight, M kg/kmol 28.00Relief Temperature of Inlet Gas or Vapor, T °C 50.00 582 RCompressibility, Z 1.00Cp/Cv , k 1.40RV Set pressure bar(g) 13.00Back Pressure bar(g) 10.00 User Input for Kb (Optional).

1.00

356.06 .

% 21 Note, do not exceed defaults.

CALCULATIONS / RESULTSpsia 242.79

psia 128.26Critical flow / Subcritical flow Subcritical FlowType of SV Balanced Bellow

0.975 Default Value as per API-520.Calculated Orifice Area, A 0.644Selected Orifice H Refer Table 1 of API Std. 526Selected Orifice Area 0.785Relieving Capacity of Selected PSV kg/h 6583

Preliminary PSV Size (Inlet x Outlet) 2"x 3"Orifice Designation H

Back Pressure Correction Factor Kb (Default value = 1)

Coefficient determined from an expression of the ratio of the specific heats (k = CP/Cv) , C

Accumulation / Overpressure .

Absolute Upstream Relieving Pressure. P1

Critical backpressure , Pcr

Effective coefficient of Discharge, Kd

inch2

inch2

STD CALCULATION FOR PSV SIZING

Self Chk:________Date:________

Chkd:________ Date:_______

Apprvd:________Date:_______

PRESSURE SAFETY VALVE SIZING CALCULATIONSVAPOUR OR GAS RELIEF

22-Apr-23

PROCESS DATAVapour or Gas ReliefFluidRelieving ScenarioVessel Design CodeRequired Flow through the device , V 1.90833333333333 4.20715483317 lb/hr.Gas Molecular Weight, M kg/kmol 29.00Relief Temperature of Inlet Gas or Vapor, T °C 75.00 627 RCompressibility, Z 1.00Cp/Cv , k 1.400RV Set pressure kPag 1100.00

kPag 0.00 User Input for Kb (Optional).

1.00

356.06 .

% 21 Note, do not exceed defaults.

CALCULATIONS / RESULTSkPaa 1432.33kPaa 756.67

Critical flow / Subcritical flow Critical FlowType of SV Conventional

0.975 Default Value as per API-520.Calculated Orifice Area, A 0.02538171064686 0.000039342Selected Orifice D Refer Table 1 of API Std. 526Selected Orifice Area 0.110Relieving Capacity of Selected PSV Nm3/min 8 Nm3/hr. 496.223

Preliminary PSV Size (Inlet x Outlet) 1"x 2"Orifice Designation D

BASED ON VOLUMETRIC FLOW RATE (Nm3/min)

Nm3/min

Back Pressure, P2

Back Pressure Correction Factor Kb (Default value = 1)

Coefficient determined from an expression of the ratio of the specific heats (k = CP/Cv) , C

Accumulation / Overpressure .

Absolute Upstream Relieving Pressure. P1

Critical backpressure , Pcr

Effective coefficient of Discharge, Kd

inch2 mm2

inch2