Patent ID: 9719232
Date: 2017-08-01
CPC Classifications: E02F,F04B,F04D,F04F

Claim:
1. A pump apparatus comprising a primary pump having a relatively low pressure fluid input and a relatively high pressure fluid output, a jet pump, associated with said primary pump fluid input, operable to prevent cavitation in the primary pump by increasing locally the pressure at said primary pump fluid input, wherein the jet pump has an input and an output, the jet pump input being in fluid communication with the high pressure fluid output of the primary pump and the jet pump output being in fluid communication with the low pressure fluid input of the primary pump, and an isolator operable to isolate the jet pump from the high pressure fluid output of the primary pump, wherein the primary pump comprises one or more controllable flow restricting valves in fluid communication via a line with the high pressure fluid output, said valves having a flow restricting condition and a non-flow restricting condition, said flow restricting condition operatively reducing the input flow to the primary pump and increasing the exhaust pressure at the primary pump fluid output, as compared to the non-flow restricting condition, wherein when the one or more flow restricting valves are in the flow restricting condition and the isolator is in an open position, the jet pump receives high pressure fluid via the jet pump input.