1) I think the electrical guys that believe the power should increase are thinking about a reciprocating pump, where the power will definitely increase when you throttle the discharge.
2) The starting of a centrifugal pump with the discharge throttled is definitely low power, BUT the starting...
Centrifugal Pump Water horse power= Q x H x S.G./3960, where Q = flow, H = head, S.G. = Specific gravity. Every centrifugal pump has a curve and reference to a typical curve will show that horsepower is reduced by throttling the discharge because the product of Q and H is being reduced and the Q...