NPSH available

[gorkus]

Hello,could you give me any advice??


underground supply tank
fluid:ethyl ether.
Flow: 7 m3/h
Tª= 20ºC
T vapor@ 20ºc= 587 mbar
density @20ºC= 0.7347 kg/dm3
suction static height=1 mts
suction pipe diameter= 37 mm
suction pipe length=5 m
atmospheric pressure= 920 mbar
estimated pipe losses = 2.14 mts
altitude= 920 mts above sea level

The NPsha value calcualted is :
NPsha=2.02 m

NPsh required by pump for this flow is 2 mts

But i have to subract the altitude correction factor to the NPsh.
how can i get these value.??

I have to subtract a 1mm de hg per 1000 feets??
is ok??

How can make higher this npsh available.??

one way is getting colder the liquid to reduce its T vapor value.
is there any more....

 

[BigInch]

Your atmospheric head is 30.4 feet.

Your 37mm suction pipe is too small.

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