Abstract: An inherently flushing piston rod is provided for use with a reciprocating pump. A piston rod having a rod portion and a piston portion is mounted for reciprocating movement within the housing of the reciprocating pump. An axial bore is defined through the piston portion and the rod portion and fluidly connects the external environment of the rod portion to an internal chamber within the piston portion. Throughout the stroke of the piston, a flushing fluid is inherently drawn through the axial bore and into the internal chamber of the piston portion, and is subsequently delivered to a flushing space defined about the perimeter of the piston portion.

Abstract: A profiled plunger is provided for use with a reciprocating pump. A flushing chamber and a main pumping chamber of a reciprocating pump are connected by a connector having an aperture, the perimeter dimension of which is less than the internal perimeter dimension of the flushing chamber. A flushing space is defined between the connector and the profiled plunger. The profiled plunger is reciprocatingly mounted through the flushing chamber, connector, and the main pumping chamber. The perimeter dimension of the profiled plunger varies along its length in a predetermined manner in order to create a predetermined flow profile of flushing fluid through the aperture of the connector.

Abstract: An inherently flushing piston rod is provided for use with a reciprocating pump. A piston rod having a rod portion and a piston portion is mounted for reciprocating movement within the housing of the reciprocating pump. An axial bore is defined through the piston portion and the rod portion and fluidly connects the external environment of the rod portion to an internal chamber within the piston portion. Throughout the stroke of the piston, a flushing fluid is inherently drawn through the axial bore and into the internal chamber of the piston portion, and is subsequently delivered to a flushing space defined about the perimeter of the piston portion.

Abstract: A pump assembly (10) is disclosed which incorporates a double acting power end (12) to operate opposed single or double acting pumps (84, 102). First and second crossheads (30, 64) are reciprocated along the pumping axis (38) by rotation of the crankshaft (20) within the power end (12). A single acting pump is connected to each of the crossheads so that the pumping stroke of the pumps occur in opposite directions as the crossheads are reciprocated. This provides a constant loading of the power end in compression to most efficiently use the power end while realizing the advantages of using single acting pumps. The crossheads are guided for motion along the pumping axis by adjustable cradles (40, 46, 70, 72) which are initially secured to the frame of the pump assembly for limited motion and the crossheads reciprocated through their range of motion to align the cradles with the crossheads and subsequently rigidly secure the frame in the aligned positions as by fastening assemblies (52).