Pump Curve - Outlet Pressure or Pressure differential
Pump Curve - Outlet Pressure or Pressure differential
(OP)
I am having a brain cramp today. Haven't worked with pumps much for a few years.
If I want to use a pump curve to estimate the flow in an existing pump system, and I can measure the pressures at the pump, do I use the difference in pressure (Pout-Pin) to correlate to the pump curve, or do I just use the outlet pressure?
My brain is telling me it should be the differential, but can't find any literature off hand that confirms this for me.
If I want to use a pump curve to estimate the flow in an existing pump system, and I can measure the pressures at the pump, do I use the difference in pressure (Pout-Pin) to correlate to the pump curve, or do I just use the outlet pressure?
My brain is telling me it should be the differential, but can't find any literature off hand that confirms this for me.





RE: Pump Curve - Outlet Pressure or Pressure differential
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Pump Curve - Outlet Pressure or Pressure differential
RE: Pump Curve - Outlet Pressure or Pressure differential
Mark Hutton
RE: Pump Curve - Outlet Pressure or Pressure differential
RE: Pump Curve - Outlet Pressure or Pressure differential
Use absolute pressures in your calculations to see how they do it.
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Pump Curve - Outlet Pressure or Pressure differential
RE: Pump Curve - Outlet Pressure or Pressure differential
RE: Pump Curve - Outlet Pressure or Pressure differential
Pump Disch Gage Press psig = Pump Suction Gage Press psig + Pump Diff H_ft * SpGrav * 62.4_pcf / 144
If there is a Suction Tank:
Pump Suction Gage Press psig = Suction_TankPress_psig + LiquidHt_overPumpCL_ft * SpGrav * 62.4_pcf - suction pipe pressure loss due to flow psig.
If tank is open to atmosphere, then tank pressure = 0 psig
If tank is closed, then tank pressure psig = whatever the gage says. That could be negative, if there is a vacuum in the tank.
If there is a Disch Tank:
Pump Discharge Gage Press psig = Disch_TankPress_psig + LiquidHt_overPumpCL_ft * SpGrav * 62.4_pcf - discharge pipe pressure loss due to flow psig.
If tank is open to atmosphere, then tank pressure = 0 psig, if closed, then = whatever the gage says.
If there is not a discharge tank:
Pump Discharge Gage Press psig = Discharge Pipe Gage Press psig
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/