PRV valve pressure drop
PRV valve pressure drop
(OP)
I'm in need of some assistance in calculating some flow vs pressure specifications, in order to make some changes to the system.
I have a PRV valve that has a preset setting of:
PRV NO.1 & 2 SET PRESSURE = 1034 KPA (150 PSI) @ 0.63 L/S (10 USGPM)
Meanwhile the design criteria states the output to be:
PRV NO.1 & 2 OUTLET = 683 KPA (99 PSIG) @ 33 L/S (520 USGPM)
= 1034 KPA (150 PSIG) @ 0.63 L/S (10 USGPM)
I'm having difficulty determining or verifying the calculation that will prove that the flow @ 520 USGPM will yield a pressure drop to 99 PSIG, which equals 10 USGPM @ 150 PSIG in this 4" system.
Something just seems odd and I've tried a number of different formula's, obviously not the correct one. I'm hoping to understand what calculation was done, and conduct it again for a flow of 400 USGPM.
The valve is a FORD 4" PRV.
Any help would be appreciated.
Thanks
I have a PRV valve that has a preset setting of:
PRV NO.1 & 2 SET PRESSURE = 1034 KPA (150 PSI) @ 0.63 L/S (10 USGPM)
Meanwhile the design criteria states the output to be:
PRV NO.1 & 2 OUTLET = 683 KPA (99 PSIG) @ 33 L/S (520 USGPM)
= 1034 KPA (150 PSIG) @ 0.63 L/S (10 USGPM)
I'm having difficulty determining or verifying the calculation that will prove that the flow @ 520 USGPM will yield a pressure drop to 99 PSIG, which equals 10 USGPM @ 150 PSIG in this 4" system.
Something just seems odd and I've tried a number of different formula's, obviously not the correct one. I'm hoping to understand what calculation was done, and conduct it again for a flow of 400 USGPM.
The valve is a FORD 4" PRV.
Any help would be appreciated.
Thanks





RE: PRV valve pressure drop
Q = Cv (ρ/ρb) * (δP) *ρw/ρ)^0.5
Q = flowrate at STP conditions
ρ = density of product at flow conditions
ρw = density of water
ρb = density of product at STP
δP = pressure drop across the valve
Cv = Valve Coefficient at a given percent open.
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