Pump low on head

[lhart]

We've got a vertical turbine pump 4 stages 3 primary and 1 inducer. The pump is tested and 50 ft low in head....we've checked the wear rings, there's no slip in the impellers, we don't expect it to be hydraulics because efficiency is fine. Impeller diameter is normal.

Any suggestions????

 

[pmover]

please clarify what is the problem?

furthermore, providing design condtions and tested conditions will be helpful as well.

good luck!
-pmover

 

[lhart]

The Pump is designed for 4375 GPM, 1780 RPM, 435 ft head, 600 BHP and 75% efficiency. Efficiency is Good, but head is 50 ft low, and BHP is also low. The pump is tested in the lab. We've tested a similar pump before and the results were fine.

 

[SteveWag]

Verify the speed of the driver.

Steve

 

[TenPenny]

Check the actual impeller diameter and speed.

 

[itsmoked]

You could have a lemon motor.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[pmover]

to supplement other posting, is the instrumentation used to determine pump performance been recently calibrated, properly installed, etc.

are you certain the impeller in the reduced head pump are identical to other similar pump?

thanks for clarifying the problem!

good luck!
-pmover

 

[BigInch]

Are you on the test bench?

http://virtualpipeline.spaces.msn.com

 

[lhart]

I think we figured out the problem. The casting used on this impeller is from a foreign casting, the previous models used a domestic casting. We're going to do a CMM to verify whether the casting is done right or wrong.

Thanks for all the input!!!!!

 

[Artisi]

Nothing like using OEM parts.