Patent ID: 7451741

Claim:
A pump comprising: a housing; a driven member coupled to the housing; a head coupled to the housing and defining a valve bore having a first diameter, a plunger bore having a second diameter, and an intermediate chamber having a third diameter, the intermediate chamber being located between the valve bore and the plunger bore; a plunger configured to reciprocate within the plunger bore, the plunger, the plunger bore, and the intermediate chamber at least partially defining a pumping chamber; and a control valve assembly coupled to the head, the control valve assembly including an actuator moveable in response to an input signal and a valve element coupled to the actuator, the valve element being received within the valve bore and being moveable between an open position and a closed position and including a body having a fourth diameter and a valve head having a fifth diameter; wherein the first diameter is no greater than the second diameter.