Centrifugal Pump Flow issue
Centrifugal Pump Flow issue
(OP)
On a chilled water system I have installed a pump which is designed to 65 ft head @ 137 GPM on the pump manufacturers curve. I am getting 46 Ft head 91 GPM and a pressure differential of 20 psi (34 In 54 Out) from the pump. It's a Taco 3009 KV series pump @ 1760 RPM and the inlet outlet piping sizes are as specified at 3". Does anybody know any possible problems that may be causing this?





RE: Centrifugal Pump Flow issue
Resticted on the suction - If the suction pressure gauge is right at the pump this is unlikely or you would see low suction pressure.
Restricted on the discharge - Also unlikely. You would expect high discharge pressure.
Alternate flow path - Flow is passing back through a spill-back line or backwards through the spare pump and not passing through the flow meter. Check the motor amps to see how that compares.
Wrong impeller - The pump could have delivered with the wrong impeller trim or pattern.
RE: Centrifugal Pump Flow issue
TTFN
RE: Centrifugal Pump Flow issue
RE: Centrifugal Pump Flow issue
RE: Centrifugal Pump Flow issue
I know its not much help. Just to say "expect the unexpected".
Going the Big Inch!![[worm] worm](https://www.tipmaster.com/images/worm.gif)
http://virtualpipeline.spaces.msn.com
RE: Centrifugal Pump Flow issue
GPM12xFtHd2 = GPM22xFtHd1
I get 115 GPM.
One other thing to check, make very sure that you've vented the evaporator bundle of air. If air is trapped in the water side of the evaporator it can affect the discharge pressure of the pump, air locking the evaporator if you will.
I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int./JCI
RE: Centrifugal Pump Flow issue
RE: Centrifugal Pump Flow issue
Additionally, from a checklist in Yedidiah's Centrifugal Pump User's Handbook:
• air in the system
• excessive leakage through wearing rings
• viscosity of liquid higher than originally designed
• impeller OD machined to a smaller dimension than specified
• partially plugged suction strainer
• NPSHA too low
RE: Centrifugal Pump Flow issue
Actual thermophysical properties of the pumped solution may negatively affect the NPSH requirements often determined for water by the pump maker.
Besides, when comparing the volumes of 1 gr of saturated water vapor developed by an equal heat input by the pump, it shows at 0 Celsius, 206300 cm3 vs 44730 cm3 at 25 Celsius (assumed testing conditions by maker).
RE: Centrifugal Pump Flow issue
good luck!
-pmover
RE: Centrifugal Pump Flow issue
RE: Centrifugal Pump Flow issue
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Centrifugal Pump Flow issue
RE: Centrifugal Pump Flow issue
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com