Hi,
I have a fundamental question regarding NPSH of pumps, in short, are NPSHa and suction pressure of a pump the same? I have searched through the forum and found numerous entries on NPSH but could not find one that answers my query.
While,
NPSHa = absolute pressure above liquid surface ± Suction Static - Friction Loss - Vapour Pressure
This is easily applicable for a pumping system which consists of an elevated open tank and a pump downstream of the tank's discharge. However, if a pump's suction pressure is provided by a booster pump upstream, how should then the NPSHa be calculated?
Please see the simplified pump system diagram as attached. I would really appreciate it if someone could provide answers on the following queries:
1) What is the difference between 'suction pressure' and 'NPSHa'?
2) Referring to the attachment, what should be the NPSHa for each of those pumps? (lift pump, booster pump and main pump)
Please help. Thank you.