Abstract: A pump assembly for limited production wells comprises an electric motor driven centrifugal pump having a controlled amount of recirculation through a jet pump. The recirculated fluid is the power fluid for the jet pump, which aspirates production fluid. The combined output of the jet pump is discharged to the centrifugal pump inlet. An electrically actuated valve in the recirculation path controls the amount of recirculation, permitting low well flow rates to be compensated for by high recirculation rates, and variation of the valve position is accomplished from the well head by the imposition of a DC signal on the AC power line for the pump motor.

Abstract: A bimodal, non-venting pneumatic relay senses the presence or absence of a first pressurized fluid and controls the supply or temination of a second pressurized fluid to associated equipment. The relay includes a segmented housing defining plural grooves which accept annular seals, a valve stem against which the seals seat and a reversible piston. The reversible piston can be selectively oriented and installed to provide either, manual rest operation to interrupt the supply of the second fluid if the first fluid supply is interrupted, the relay requiring manual resetting to reestablish supply of the second fluid, or automatic reset operation, wherein restoration of the second fluid supply is achieved automatically if the first fluid pressure is re-established subsequent to an interruption.