A pump for providing a pressurized fluid flow. The pump includes a pump casing that defines a pump chamber. A pump shaft is has a head end in the pump chamber; the head end has a circumferential outer surface. The pump shaft head end has inwardly extending piston chambers. A discharge manifold is formed in the pump shaft head end. The discharge manifold has one end in fluid communication with the piston chambers and a second end in fluid communication with a discharge conduit that extends outside of the pump casing. A piston is mounted in each piston chamber. The pistons are formed with flow-through bores that provide fluid communication between the pump chamber and the piston chambers. A suction valve associated with each piston regulates fluid flow from the pump chamber through the flow-through bore into the associated piston chamber. Discharge valves regulate fluid flow from each piston chamber into the discharge manifold. The head end of the pump shaft is axially offset from the center axis of the pump chamber. As the pump shaft is rotated, the pistons engage in reciprocal motion in their piston chambers. Fluid is introduced into the pump chamber. When each piston is in its extended position, the suction valve allows fluid flow into the piston chamber. When each piston is retracted, it forces the fluid in the associated piston chamber through the discharge valve, through the discharge manifold and out the discharge conduit.