80 and a second solenoid control valve 82 the first valve 80 controls the flow of feedwater through the first feed port 28 and into the return chamber 44 the second valve 82 controls the flow of feedwater out of the return chamber 44 and through the second feed port 30 the pump 10 also contains a piston detection switching system that detects the position of the piston and switches the valves between open and closed positions in the preferred embodiment the switching system includes a first transducer 84 and a second transducer 86 both attached to the housing body 22 the transducers are coupled to a detection element 88 located within the first head 38 the transducers may be hall effect devices capacitance proximity sensors or any other position detection means alternatively the pump 10 may employ other position detection devices such as reed switches the transducers are connected to a control circuit 90 the control circuit is coupled to the solenoids of the first valve 80 and a second valve 82 when the detection element 88 is adjacent to the first transducer 84 the transducer 84 provides a signal to the control circuit 90 in response to the first transducer signal the control circuit 90 switches the first valve 80 off and the second valve 82 on so that feedwater within the return chamber 44 can flow into the drain line when the detection element 88 is adjacent to the second transducer 86 the transducer provides a signal to the control circuit 90 which switches the second valve 82 off and turns the first valve 80 on so that feedwater flows into the return chamber 44 the control circuit 90 may contain a latch that sets and.