We have a water pump which has about 90% of its feed from one source (Stream A) and 10% from another (Stream . There is a tee about 5m before the suction of the pump.
Recently we had a failure on stream B which resulted in losing the full 10% flow. There were minimal changes in suction pressure but we lost 40% of our discharge pressure and flow dropped by about 20%. As far as I can tell we didn't reach any cavitation, the NPSHr (0.8m) is significantly lower than the NPSHa (13m).
Is it expected that a sudden loss of 10% of your feed would result in such drastic discharge pressure loss and loss in flow? I would have expected to temporarily lose the 10% of the flow but no more. Can this be defined as cavitation or is it something else I am unaware of? The main source of liquid comes from a vessel which has enough inventory to compensate for the loss in flow.
Thanks
Emily