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VishalB
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Join Date: Jul 2010
Posts: 31
Good Answers: 1

Positive Displacement (Controlled Volume) Pump

09/04/2010 7:18 AM

What is the significance of NPSH (available) for controlled volume / diaphragm pump?

What is the NPSHA criteria while selecting such pumps?
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Anonymous Poster
#1

Re: Positive Displacement (Controlled Volume) Pump

09/04/2010 8:38 AM

Avoiding cavitation.

This has quite good and clear discussion on it and this also talks about it including NPSHA
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VishalB
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Join Date: Jul 2010
Posts: 31
Good Answers: 1
#2
In reply to #1

Re: Positive Displacement (Controlled Volume) Pump

09/06/2010 12:39 AM

Thanks for the article on NPSH.

In my case, I have to use a double diaphragm pump and the NPSHA is only 0.5 m without acceleration head. The pump has to provide 16.3 LPH at disch pressure 4 kgf/cm2. Viscosity is 6.4 cP.
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PWSlack
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#3
In reply to #2

Re: Positive Displacement (Controlled Volume) Pump

09/06/2010 4:36 AM

At that sort of flowrate, the NPSHA shouldn't be an issue. "JFDI"/"Nike".

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Anonymous Poster
#4
In reply to #3

Re: Positive Displacement (Controlled Volume) Pump

09/06/2010 7:57 AM

I agree. The flow is very low as is the differential pressure.
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VishalB
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Join Date: Jul 2010
Posts: 31
Good Answers: 1
#5
In reply to #4

Re: Positive Displacement (Controlled Volume) Pump

09/06/2010 11:29 PM

Thanks again.

One more thing I would like to know - as in case of centrifugal pumps, do we have to mention in our datasheets whether the NPSHA given is underside of baseplate or elsewhere?
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