A fluid cylinder for a fluid end section of a reciprocating pump is described. The fluid cylinder includes a body defining a pressure chamber in fluid communication with a plunger bore, the plunger bore comprising a packing segment configured to hold a packing stack, and a tubular sleeve in interference-fit within the plunger bore. The sleeve has an internal passage configured to accommodate a plunger operatively reciprocating within the plunger bore during operation of the reciprocating pump, and a stepped shoulder disposed at an interface between a first segment of the sleeve and a second segment of the sleeve, where a diameter of the first segment being greater than a diameter of the second segment of the sleeve. An annular seal is disposed at the stepped shoulder f the sleeve between the sleeve and the plunger bore. A packing flange is secured within the plunger bore abutting an end portion of the first segment of the sleeve.

A high-pressure fuel pump includes a pump housing, a pump piston accommodated in a receiving opening of the pump housing, a high-pressure seal which surrounds the pump piston in a sealing manner and which seals off a high-pressure region from a low-pressure region, and a guide device which comprises at least two guide portions that are axially spaced apart from one another and guide the pump piston with a sliding fit. The at least two guide portions are arranged in the receiving opening of the pump housing. A first guide portion is arranged, as seen in an axial direction, on a side of the high-pressure seal facing toward the delivery space. And a second guide portion is arranged, as seen in the axial direction, on a side of the high-pressure seal facing away from the delivery space.

A structural reinforcement and biocompatible pump head for a pump includes a reinforcement structure having a plurality of ports and fluid pathways therein. The fluid pathways in the reinforcement may be coated or lined with a biocompatible material to form a biocompatible pump head useful for liquid chromatography and other analytical instrument systems. The biocompatible material may be injection molded into the fluid pathways of the reinforcement structure and may be machined after core pins are removed to obtain a desired surface finish and/or size of the biocompatible fluid pathways of the pump head.

A fluid end includes a housing having a bore extending toward a cavity and a wear sleeve positioned within the bore. The fluid end also includes a plunger positioned within a plunger bore extending through the wear sleeve, the plunger reciprocating within the plunger bore. The fluid end further includes a wear sleeve retainer coupled to the housing and positioned to block axial movement of the wear sleeve, the wear sleeve retainer having external threads along a body that engage internal threads formed in the housing. The fluid end also includes an anti-rotation system, coupled to the housing, the anti-rotation system engaging the wear sleeve retainer to block rotation of the wear sleeve retainer in at least one direction. The fluid end further includes a packing nut coupled to the wear sleeve retainer.

A manually operated pump exhibiting numerous improvement over existing such pumps is described. The pump can include a cylinder that is removeably mounted to a molded valve box of unitary construction. The valve box can feature a valve plate covering a valve chamber and housing an inlet valve and an outlet valve. In some instances, the pump includes a molded piston of unitary construction to which a pair of opposing piston cups is mounted. In some cases, the pump includes a filler cap forming an inlet adapted to deliver a priming fluid into the cylinder. In some cases, the pump includes a stopper cap adapted to prevent a pump shaft from being fully pulled out of the cylinder.

A multi-channel positive displacement piston pump apparatus includes a motor and a plurality of positive displacement piston pumps driven by the motor. The plurality of pumps are aligned in a stacking direction, and each pump has an intake port and an outlet port, wherein the intake ports and the outlet ports of all pumps face in the same direction generally perpendicular to the stacking direction. In a method for retrofitting a positive displacement piston pump for use in a multi-channel pumping apparatus, an outlet port of a pump housing of the pump and a flush outlet port of the pump housing are plugged and an alternative fluid path is formed within the pump housing. The outlet port is disposed in line with an inlet port of the pump housing but on an opposite side of the pump housing. The flush outlet port is disposed in line with a flush inlet port of the pump housing but on an opposite side of the pump housing. In this way, the alternative fluid path is formed between the inlet port and the flush inlet port.

Apparatus and method contemplating a high pressure fluid end assembly having a body defining a body bore and defining a groove in the body intersecting the body bore. A closure is joined to the body and forms a sealing surface. A seal is mounted to the body in the groove and configured to extend from the groove beyond the body bore to seal against the sealing surface formed by the closure.

A long sleeve cartridge for being inserted into a fluid end block of a pump is disclosed. The long sleeve cartridge includes a body and a sleeve bore extending through the body. The sleeve bore includes a first inner diameter and a second inner diameter. The first inner diameter is less than the second inner diameter. A first aperture is located on the body, and a second aperture is located on the body in a radial position substantially diametrically opposite of the first aperture. A packing seal assembly is secured within the long sleeve cartridge. The packing seal assembly includes one or more seals and a biasing mechanism to provide a compression force on the seals. The packing seal assembly is arranged within the second inner diameter when the packing seal assembly is disposed within the long sleeve cartridge.

A fluid end assembly comprising a housing having multiple conduits formed therein. A tubular sleeve is installed within one of the conduits and is configured to house a plurality of packing seals. A seal is installed within a groove formed in the walls of the housing surrounding the tubular sleeve such that the seal engages an outer surface of the tubular sleeve.

A method is provided for forming wear-resistant layer on the surface of cylinder bores a cylinder drum of a hydrostatic axial piston machine within which a respective piston is moved in a manner subject to intensive wear. The cylinder bores are gas nitrocarburized in two stages to minimize the wear and include a thin uniform connecting layer that has a thickness of 4 to 16 μm and a comparatively thick underlying diffusion layer.