Pump Flow Rate loss over time
Pump Flow Rate loss over time
(OP)
One of our pump stations equipped with two Flyght (6.5)hp pumps has experienced a decreased flow rate over time.
From the pump performance curve, our duty point is 144 gpm @ 57.6 ft of Head
Recent test --> 74 gpm @ 49.7 ft of Head
Our pressures are consistent and we just adjusted the clearances, any ideas why the flow rate has dropped almost 50 percent?
Thank you for your time and energy!
From the pump performance curve, our duty point is 144 gpm @ 57.6 ft of Head
Recent test --> 74 gpm @ 49.7 ft of Head
Our pressures are consistent and we just adjusted the clearances, any ideas why the flow rate has dropped almost 50 percent?
Thank you for your time and energy!





RE: Pump Flow Rate loss over time
RE: Pump Flow Rate loss over time
Your pumping system does not operating appear to be operating on the pump curve so that indicates a problem. You need to inspect the pumping system and get some further informatin.
The pump may be clogged?
The forcemain may be fouled?
What is the elevation of the water in the lift station?
What is the velocity in the force main?
Is the flow meter accurate?
etc
RE: Pump Flow Rate loss over time
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Pump Flow Rate loss over time
One way to check this out is to reproduce the pump curve:
1. The shut in head matches the shut in head on the curve
2. The further you produce points to the right of the shut in head, the further the droop away from the pump curve....for sure you have debris in the pump suction