Abstract: A liner retention system for a reciprocating pump having a piston and a piston rod operating in a cavity of a frame. The system includes a cylindrical liner for the piston and piston rod, the liner having a radially extending external shoulder. A liner clamp plate has a central opening receivable over the liner and a plurality of stud apertures. A plurality of studs extends from the frame, each stud terminating in a threaded end spaced from a module block. At least one compression sleeve has an inside diameter larger than an external diameter of the stud. Tensioner mechanism secures each stud to the liner clamp plate to thereby secure the cylindrical liner to the module block.

Abstract: An apparatus and method to assemble and disassemble a valve cover locking screw assembly for a reciprocating pump module block. The module block has a bore, a removable valve cover closing the bore, and a valve cover locking ring securable to the block and surrounding the bore with internal threads. A valve cover locking screw has cylindrical walls with external threads, a closed top, and an open bottom. A plurality of threaded bolts engage a plurality of threaded openings through the cylindrical walls of the locking screw so that the bolts force the valve cover against the module block thereby creating a fluid tight seal.

Abstract: A self-tightening retaining system for securing a closure in position closing an access port of a pump housing. The system includes a retaining cover for obstructing removal of the closure from a bore of the access port. The cover has external threads interengageable with screw threads of the bore. A locking device is configured for being secured to the cover such that the locking device rotates together with the cover. The locking device has a fastener receivable in a hole of the closure and has external threads interengageable with threads of the hole. The threads of the cover and the threads of the fastener are spiraled in opposite directions such that when the cover rotates in a loosening direction, the fastener becomes tightened in the hole of the closure thereby stopping the rotation.