Abstract: A high-pressure plunger pump includes a pump housing centered on an axis and including a main body having two axially spaced ends, and a pump head secured to one of the ends of the main body. A plunger coaxially extends into the pump housing and a sleeve is floatingly supported on the plunger. The sleeve has two end portions one of which is closer to the pump head than the other, converges toward the pump head and has an axial end face. An insert body is positionally secured in the pump housing at the one end portion of the sleeve and bounds a circumferentially extending annular suction channel with this one end portion. The insert body includes an annular shoulder having a substantially axially facing seating surface. Pressure and suction valves are coaxially arranged within the housing.

Abstract: A housing has an interior provided with two communicating compartments, and valve seats are located between these compartments. An inlet communicates with one and an outlet with the other of the compartments. A pressure valve is located in the other compartment and sealingly engages one of the valve seats unless the pressure in the one compartment exceeds the pressure in the other compartment. A plunger is reciprocable in the one compartment toward and away from the valve seat between a suction stroke and an expelling stroke. A suction valve member slidably engages the plunger and is guided solely by the same. The suction valve member sealingly engages the valve seats and moves out of engagement with the same to travel with the plunger during the suction stroke. An abutment limits the travel of the suction valve member during the suction stroke of the plunger.

Abstract: A plunger pump has a pump housing defining a pumping chamber into which a plunger extends for reciprocation between a retracted and an extended position. A sleeve valve is mounted on the plunger for displacement longitudinally thereof and for limited reciprocation therewith between an open position and a closed position in which it subdivides the pumping chamber into a pumping space within, and a suction space without, the sleeve valve. Inlet and outlet ports communicate with the suction and pumping spaces respectively. A sealing sleeve is mounted on a portion of reduced diameter of the plunger and defines with the latter a compensating space which communicates with a region of the interface between the sleeve valve and sealing sleeve at which the pressure of the fluid escaping from the pumping space through the interface is lower than the pumping pressure existing in the pumping space during the pumping stroke of the plunger.