NPSH required for water 1

[steveb1111]

We have vendor pump curve that report NPSH required in feet of water, which I understand is the norm.

The fluid being pumped is pentane. Given the differences in vapour pressures and densities between pentane and water, using NPSHr for water surely can't be right. The NPSH available has been calculated based on pentane properties.

I've looked through other threads, but can't find a recommended approach to deal with this situation.

I would value the learned insights of forum members.

 

[StoneCold]

Look at the "feet of water" as a unit of measure, like "inches of mercury". So if you have converted your NPHSa to units of "feet of water" Then you can use the pump curve and check your NPHSa against NPHSr.

Following me?

Regards
StoneCold

 

[25362]

If you wish to know about the "reserve" of NPSHa by pumping pentane rather than water, see thread407-152358, in particular the links brought by quark.