A fluid end having its fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits that each comprise a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.

A fluid end having its fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits that each comprise a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.

A bearing attachment system for a pump product having a seal carrier and a cover plate. The attachment system is configured to produce a force deflection curve that provides a clamping force on a pair of tapered roller bearings such that a tight bearing endplay on the tapered roller bearings is maintained through a full range of manufacturing tolerances. The geometric shape of the cover plate and the top surface of the seal carrier provide the desired deflection characteristics.

A water part module for attaching to a piston pump, which has a support unit that can be releasably attached to the piston pump and at least respectively one suction module and pressure module that is releasably connected to the support unit. The support unit and each suction module and each pressure module are designed such that the suction and pressure modules are interchangeable with one another. Each suction and pressure module have at least two planed side faces of which one acts as a lower connection face and a side face adjoining the lower connection face acts as a lateral connection face. A duct inside the respective suction and pressure module, which can be closed and opened by a valve in the respective suction and pressure module, ends on one side in the lower connection face and on the other side in the lateral connection face.

A water part module for attaching to a piston pump, which has a support unit that can be releasably attached to the piston pump and at least respectively one suction module and pressure module that is releasably connected to the support unit. The support unit and each suction module and each pressure module are designed such that the suction and pressure modules are interchangeable with one another. Each suction and pressure module have at least two planed side faces of which one acts as a lower connection face and a side face adjoining the lower connection face acts as a lateral connection face. A duct inside the respective suction and pressure module, which can be closed and opened by a valve in the respective suction and pressure module, ends on one side in the lower connection face and on the other side in the lateral connection face.