Pump Cavitation
Pump Cavitation
(OP)
Could a short pipe length on the suction of an end suction pump cause it to cavitate? Would a suction diffuser help this condition if so?
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RE: Pump Cavitation
Do you mean a short 'straight' run? Or just short run?
RE: Pump Cavitation
Please provide more detail on the installion so that we can review the info' and assist you.
RE: Pump Cavitation
All I have to do is look around my plant for pumps that consistently have high vibration and poor reliability. A lot of them are piped up on the suction with an eccentric reducer directly to an elbow turning the line to the vertical with a block valve in the vertical leg. This takes up the least space and uses the least fittings. But it does not provide the ideal flow to the pump suction. For some pumps it might not make any difference. But, if you have a pump with a high suction specific speed, or if you have to run the pump well below best efficiency point flow, you may have problems that would not exist with a longer straight run of pipe on the suction.
Johnny Pellin
RE: Pump Cavitation
This is what I was thinking as well. Do you have any comment whether a suction diffuser could help alleviate this condition?
John
RE: Pump Cavitation
RE: Pump Cavitation
HVACH... bad configuration. Sorry, no. A very very bad configuration. ... Or .. what do you think about looking again for those rocks?
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"Pumping systems account for nearly 20% of the world's energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Pump Cavitation
So, back to my quesition. Does anyone think a suction diffuser will help the situation or does anyone have any "constructive" comments that would provide a minimum cost fix?
RE: Pump Cavitation
" 6" pipe on the inlet with basket stainer right at the suction flange of the pump, then about 1 foot of pipe with
How can you have a basket strainer at the pump suction flange then 1ft of pipe ---- do you mean basket strainer on the inlet pipe then 1ft of pipe to the pump.
Where is the water level (inlet side) in relation to the pump centre line - above or below.
RE: Pump Cavitation
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"Pumping systems account for nearly 20% of the world's energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Pump Cavitation
Verify that the pump is running at an acceptable operating point relative to BEP. Just because the pump manufacturer says the pump can run down to 10% of BEP doesn't mean you won't experience any suction recirculation cavitation running there. The closer you can get to BEP, the better. If you can, run a test by changing the flow closer to BEP to see if this eliminates the cavitation.
Johnny Pellin
RE: Pump Cavitation
RE: Pump Cavitation
RE: Pump Cavitation
It looks like you have room for the piping correction required, it should be relatively painless.
RE: Pump Cavitation
RE: Pump Cavitation
Raise the path? It looks like every option is going to going to have a significant cost. How often does this pump fail?
RE: Pump Cavitation
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"Pumping systems account for nearly 20% of the world's energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Pump Cavitation
Certainly streets ahead of what you currently have.
RE: Pump Cavitation
You can put the strainer on the suction side as suggest by Artisi, but you should install a DP switch to give an alarm. If not you will end-up damaging the pump when the strainers is filled with rubbish.
RE: Pump Cavitation
Overall, this configuration does not look that bad. I don't like the butterfly valve much. We very rarely ever use them since they can present more flow disruption and turbulence than a gate valve. If you are removing the strainer anyway, I would shorten the new spool piece to make room for a gate valve in place of the butterfly. For the price of one short spool piece and a valve, you can easily determine if these are the problems.
Johnny Pellin
RE: Pump Cavitation