In our [ Lube Oil ] plant , for high NPSH of feed charge pumps there is a sundine booster pump . The strange thing is that, flow is like follows
feed surge drum - booster pump - NRv- discharge valve - - line combines with standby pump - NRV- suction of charge pump.
I could not find the satisfacory explanation for the 2nd NRV in that position,Anybody will plz explain me