Hi All,

i would to know your opinion on parallel pump operation. Two (2) identical high pressure Boiler feedwater pump with booster pump - multistage pumps (#1 and #2) driven by steam turbine as the driver. Operation:
initial operation:
pump#1 Pump#2
flow rate 1100 t/h 1100/th
Discharge pressure 320 kg/cm2 320 kg/cm2
RPM 5520 5467
Steam turbine governor opening 81% 82%

operation after modification of ONLY pump #2
mp#1 Pump#2
flow rate 1135 t/h 1042 t/h
Discharge pressure 320 kg/cm2 320 kg/cm2
RPM 5594 5588
Steam turbine governor opening 86% 77%

from the above, can we assume that pump#2 after modification has lower capacity at same head and therefore lower eff than pump#1 since pump#2 operated at higher speed but lower flow compared to condition before modification.