Abstract: A pump has a housing including at least one fluid channel; a motive fluid inlet port; a suction fluid inlet port; and a discharge port. The pump also includes a venturi disposed in the fluid channel of the housing. The venturi is connected by way of the fluid channel to the motive fluid inlet port, the suction fluid inlet port, and the discharge port. A ball check valve is operatively disposed between the motive fluid inlet port and the venturi for controlling the flow of motive fluid. The pump further includes an actuator assembly for actuating the ball check valve. In the preferred embodiment, the ball check valve has only an opened position and a closed position.

Abstract: A pump includes a valve mechanism having an opened position and a closed position. The pump further includes a spring assisted mechanism for selectively moving the valve mechanism between the opened position and the closed position, and a fluid detector for detecting the level of a pumping fluid. The fluid detector is pivotally connected to the spring assisted mechanism and has a first range of pivotal travel and a second range of pivotal travel. The fluid detector further engages a spring of the spring assisted mechanism only at one portion of the first range of pivotal travel, and engages the spring of said spring assisted mechanism only at one portion of the second range of pivotal travel. The fluid detector is disengaged from the spring of the spring assisted mechanism at all other portions of the first range of pivotal travel and of the second range of pivotal travel.