Re: Pump Commissioning

From: <elie>
Date: Fri May 19 2006 - 20:05:00 EDT

It looks like the discharge pressure from the pump is set by the pipeline hydraulic (water flowrate, pipe size, pipe length, etc. and end of pipe or delivery pressure); The highre the flow rate, the higher the upstream pressure or pump discharge pressure.

   At 2000 GPM the discharge pressure was 39 psig.

   After you installed the larger impeller, the pump now pumps more than 2000 GPM of water and the discharge pressure went up from 39 psig to 56 psig.

   I don't se any problem. Am I missing something?

   Cheers,
   Elie AlTawil, Process/Pipeline/Piping/facility design engineer.    iN CoLoRaDo

rommel noderama <nrommelh@yahoo.com> wrote:

   Dear All,

   I have commissioned a centrifugal pump months ago and here are the pump name plate 75ft TDH and 2000 gpm. The commissioning result are the following:

   Suction pressure: 13 psi
   Valve Shut Discharge pressure: 54 psi    Actual Impeller Diameter Base on submitted Pump Curve is: 10.2 inches (base on the data gathered by valve shut delta pressure)

   Final Discharge pressure: 39 psi @ 2000gpm or 60 ft TDH only (valve already adjusted to meet 2000 gpm requirement)

   The problem is the pump did not meet its 75 ft. TDH, I contacted the supplier and opted to increase the impeller diameter.

   Now when the new impeller was installed, I gathered the following:

   Suction Pressure: 13 psi
   Valve shut Discharge pressure: 56 psi    When we open the discharge valve the pressure is still the same (56 psi), pressure gauge is calibrated and valve is functioning well. For me the pressure should lower down to its operating limit prior to adjusting of valve base on flow requirement. What seems to be the problem please enlighten me. By the way the fluid is water.

   Regards,

   Rommel
   Facilities Enginner

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[Non-text portions of this message have been removed] Received on Fri May 19 20:05:00 2006