Abstract: The liner retainer assembly includes a cylinder that is mounted on a module of the fluid end of a pump. The cylinder has an aperture for receiving a liner and a retaining piston. A retaining nut is secured on the end of the retaining piston and engages one end of the liner. The retaining piston forms a fluid cavity and a spring cavity within the cylinder. The spring cavity houses a plurality of springs which bias the piston, retaining member, and liner towards the module, thus providing a resilient securing force. The fluid cavity communicates with a supply of hydraulic fluid for biasing the piston away from the module to relieve the springs. By pressurizing the fluid cavity, the springs are compressed to disengage the retaining member from the liner and allow the unthreading of the retaining member and then the removal of the liner.

Abstract: A reciprocating pump valve and seat having mating frustoconical seating surfaces in which a resilient sealing insert on the valve is below a rigid disc portion of the valve, with a sealing surface on the insert engageable with the seating surface of the seat radially outwardly from the portion of the seating surface of the seat engageable by the rigid disc portion of the valve.

Abstract: A reciprocating pump piston includes a piston rod which is adapted to be disposed within a cylinder. A piston hub is secured to the piston rod and is adapted to be reciprocated thereby within the cylinder. The hub includes a flange portion having a cylindrical outer periphery of slightly smaller diameter than the inner diameter of the cylinder and a generally cylindrical body portion having a diameter smaller than the flange portion. An annular piston seal ring is disposed about the hub body portion. The seal ring includes an inner leg disposed in mating relation with the body portion and an outer leg defining an annular sealing lip which yields radially inward upon insertion of the hub into an associated pump cylinder. Yielding of the outer leg is to a predetermined extent sufficient to block dislodgement of the inner leg from mounted association with the hub body portion.