NPSHa calculation of pump
NPSHa calculation of pump
(OP)
hi,
now i working on the NPSHa calculation for the pump. there is a drum with overhead nitrogen seal at the suction side of pump. how to calculate the NPSHa for the pump? how to considerate the pressure of suction side? use the vapor pressure of the liquid may be not suitble in this case.
now i working on the NPSHa calculation for the pump. there is a drum with overhead nitrogen seal at the suction side of pump. how to calculate the NPSHa for the pump? how to considerate the pressure of suction side? use the vapor pressure of the liquid may be not suitble in this case.





RE: NPSHa calculation of pump
NPSHA = system pressure of suction equipment - vapor pressure - static head (from the vessel bottom tangent line) - line friction loss - pressure drop of suction equipments and instrumentation
this formula is applicable for all condition in pump NPSH calculation.
thanks
saffari
RE: NPSHa calculation of pump
Not at all going into details.
I have a simple asking query as if what is to be handled by pump?
Since the reply is/would obviously be the process liquids not N2 gas.Therefore the sealing pressure should not govern NPSHa for designing I understand.
Best Regards
Qalander(Chem)
RE: NPSHa calculation of pump
the pumped flow is HDO/LVGO,that is the feed of Diesel hydrotreating unit. there is a feed surge drum with nitrogen seal at the top.OT is 149ºC, and the vapor pressure is 0.06kg/cm2a.
Does the nitrogen seal have any effect on the calcultion.
nitrogen may be saturated in the liquid.
RE: NPSHa calculation of pump
However more learned colleagues at the forum may jump-in with helping loads of useful advises indeed!
The general formula equation given above by alisaffari should be helpful for your purpose,I assume.
Best Regards
Qalander(Chem)
RE: NPSHa calculation of pump
"Pumping Liquids Loaded With Dissolved Gas"
i have found some infomation about the dissolved gas affect the vapor pressure of the pumped flow.
may be i do not express clearly!
Thanks again!
RE: NPSHa calculation of pump
Johnny Pellin
RE: NPSHa calculation of pump