Abstract: A fluid pump including a fluid end body having a plurality of interconnected fluid paths, a plurality of valves located within the plurality of interconnected fluid paths and a plunger located within at least one of the plurality of interconnected fluid paths to push a first portion of the volume of fluid through a first section of the plurality of interconnected fluid paths and from a second fluid port during a push stroke to push a second portion of the volume of fluid through a second section of the plurality of interconnected fluid paths and from the second fluid port during a back stroke. Each of the plurality of valves is movable between an open position and a closed position to form the first section and the second section.

Abstract: An electronic device is configured to change a light state, e.g. the brightness, of at least one light source (11) while a user is watching content being displayed on a display (19) and detect the user's attention shifting away from the display (19). The electronic device is further configured to determine whether the attention shift coincides with the change of the light state and store a preference for the light state in dependence on the attention shift coinciding with the change of the light state. The preference is preferably a preference for a light state with a less pronounced light effect than the changed light state.

Abstract: A piston pump, comprising: a main body (2); a head (3), sealingly associated with the main body (2) at a coupling surface (3a); a pumping chamber (4), at least one portion of which is afforded in the head (3); a piston (5), provided with a head (5a) that is sealingly slidable in the pumping chamber (4) along a longitudinal direction (X); a valve seat (6), afforded in the head (3), which has an access opening (6a) on the coupling surface (3a) and is placed in communication with an intake manifold (S), with a delivery manifold (D) and with the pumping chamber (4); a suction valve (7) and a delivery valve (8) arranged sealingly inside the valve seat (6); wherein the suction valve (7) is movable between an opening position, in which it enables communication between the intake manifold (S) and the pumping chamber (4), and a closing position, in which it prevents communication between the intake manifold (S) and the pumping chamber (4); and wherein the delivery valve (8) is movable between an opening position, in

Abstract: A fluid end comprising a plurality of fluid end sections positioned in a side-by-side relationship. Each fluid end section is releasably attached to a connect plate. Each connect plate is attached to a power source using a plurality of stay rods. Each fluid end section comprises a housing in fluid communication with a pair of intake manifolds and a discharge conduit. A fluid routing plug is installed within each housing and is configured to route fluid throughout the housing. A plunger is installed within stuffing box attached to each housing. A number of features, including the location of seals within bore walls and carbide inserts within valve guides, aid in reducing or transferring wear.

Abstract: The invention relates to a high-pressure rotor nozzle comprising a main body having a channel for supplying a highly pressurised fluid, a nozzle holder which can be rotationally driven for this purpose via a hydraulically generated torque, and which has at least one nozzle connected to the channel in a manner open for fluid and acting in accordance with an axial recoil, wherein a leakage chamber forming a hydraulic axial bearing during operation is provided between the main body and the nozzle holder that can be axially adjusted in relation to same in a recoil-dependent manner, with said leakage chamber being connected to a first gap seal between the main body and the nozzle holder guiding a leakage fluid, wherein the high-pressure rotor nozzle is designed in such a way that the leakage chamber transitions into at least one throttle gap circumferentially surrounding the nozzle holder in an axial sub-region and varying in the axial extension thereof according to the movement path of the nozzle holder, wherein

Abstract: A high-pressure pump has a metering valve and a valve stopper. The stopper has a regulation portion which an end surface of the valve is brought into contact with. An outer diameter of the regulation portion is equal to an outer diameter of the outer peripheral surface of the valve. A cylindrical sleeve is disposed around the regulation portion. When the end surface of the valve is in contact with the regulation portion, the sleeve covers a tapered surface of the valve.

Abstract: A fuel pump having a housing which defines a pump chamber with an inlet and an outlet. A piston is reciprocally mounted in the pump chamber. An inlet valve is mounted fluidly in series between the pump chamber and the housing inlet which opens and closes the inlet in synchronism with the reciprocation of the piston. A rotary valve is mounted fluidly in series with the housing outlet and the rotary outlet valve is rotatably driven in synchronism with reciprocation of the piston. The rotary valve is configured so that it is fluidly open only at one or more predetermined angular positions of the rotary outlet valve. The open and close timings of the rotary inlet and outlet valves are completely controlled by a motor in order to control the fuel pressure, especially to avoid excessive fuel compression and resulting fuel pressure fluctuation.

Abstract: The invention relates to a cylinder piston arrangement for an especially volumetric fluid pump or a fluid motor, preferably comprising at least one axial expansion tubular membrane piston defining at least one inner pulsating working chamber. A particular field of application for such pumps or motors is the operation thereof with fluids loaded with extraneous materials, especially abrasive granulated materials. Especially high-speed machines with high working pressures of between a few hundred to a thousand bar are required, the energetic and also volumetric degree of efficiency thus becoming highly important factors. The aim of the invention is therefore to create pumps or fluid motors which are characterized by high degrees of efficiency and long service lives. To this end, at least one clearance driving body (TK1) is actively connected to the pulsating working chamber (AR).

Abstract: Plunger pump fluid ends incorporate housings with structural features that facilitate manufacture while providing improved internal access, reduced weight, and reduced likelihood of fatigue failures compared to conventional fluid end housings. Certain fluid ends incorporate frangible pressure relief means in suction valves for protection from overpressure-induced catastrophic failure. Oblong bore transition areas, when present, and barrel-profile central cavities provide obtuse bore intersection angles and effectively reduce fluid end weight while reducing peak cyclic fluid end housing stress by redistributing stress within the fluid end housing.

Abstract: A high-pressure fuel pump for an internal combustion engine is described. The high-pressure fuel pump includes an improved configuration that beneficially simplifies certain features of the high-pressure fuel pump. More specifically, the disclosure provides for an inlet check valve positioned along an inlet fuel circuit and an outlet fuel circuit of the high-pressure pump that provides a path for a low-pressure inlet fuel flow to and a path for a high-pressure output fuel flow from a pumping chamber of the fuel pump. Because of the configuration of the inlet check valve and the outlet check valve, the complexity of high-pressure fuel pump is beneficially reduced, decreasing the cost of components and assembly and improving the life and reliability of high-pressure fuel pump.

Abstract: With reference to FIG. 1, the present invention provides a fuel injector (19) comprising a reed valve (35). The reed valve has at least one orifice and at least one reed valve blade, the or each reed valve blade having a valve head attached to at least one resilient spring arm. The or each valve head opens and closes a respective orifice in the valve seat. A support surrounds the reed valve blade(s). Each spring arm extending inwardly from the support. Each spring arm is curved.

Abstract: To reduce the clearance volume for a crank-side concentric suction and pressure valve, it is proposed to arrange a sealing 20 axially abutting on the suction and pressure valve 2,3, wherein the sealing 20 consists of a number of pressure packings 21a, 21 which are arranged axially one behind the other.

Abstract: Oilfield equipment is provided that includes a base material less subject to abrasion, corrosion, erosion and/or wet fatigue than conventional oilfield equipment materials such as carbon steel, and a reinforcing composite material for adding stress resistance and reduced weight to the oilfield equipment.

Abstract: A fluid end for a reciprocating pump is provided that includes a base material less subject to abrasion, corrosion, erosion and/or wet fatigue than conventional fluid end materials such as carbon steel, and a reinforcing composite material for adding stress resistance and reduced weight to the fluid end.

Abstract: A valve seat for use in a high pressure pump comprises an inner portion force fit within an outer portion. The outer portion has a fluid plenum at an outer peripheral surface. Fluid passages extend radially inwardly to communicate with a valve recess in the inner portion. A seal housing for a high pressure pump comprises an outer portion and an inner portion. The inner portion is force fit within the outer portion. The inner portion has an inner bore having a first location to receive seal packings, and a second location to receive valve spring structure. The inner portion has a curved surface that bottoms out against a curved surface within the outer portion.

Abstract: A compressor may include a compressor body defining a compression cylinder, a compressor head coupled to the compressor body, and a valve plate assembly disposed between the compressor head and the compressor body. The valve plate assembly may include a first valve plate formed as a unitary casting and defining a suction chamber exposed to a suction pressure region of the compressor.

Abstract: A valve plate assembly for a compressor includes a first plate and a second plate disposed between and providing communication between a compressor head and a compressor body. The first and second plates are separated by a spacer supporting a load approximately centrally relative to the first and second plates.

Abstract: A fluid end for a reciprocating pump including a body having a base, a side and a longitudinal opposing side, a cylinder bore formed horizontally through the body and a vertical bore intersecting the cylinder bore defining a high stress region proximate the intersection, and a tension member extending through the body substantially parallel to the longitudinal axis of the body, wherein the tension member provides a compressive load on the body reducing the stresses encountered in the region during operation of the fluid end.

Abstract: An air valving system for a reciprocating piston pump (5) which uses piston (10) actuated poppet assemblies (40) to control the main air valve (16) shift. The valve exhaust is vented (50) directly to atmosphere rather than through the main exhaust to ensure reliability. A ramped detent (32) prevents the air valve (16) from centering.

Abstract: A reciprocating compressor is provided with a discharge valve having an area inward of a valve seat which is greater than the area of the discharge port. The valve seat also has a distinct shape compared to the valve port in preferred embodiments. The increased area within the valve seat results in an increased force tending to open the valve from a compressed fluid. On the other hand, since the valve port remains relatively small, the flow losses are not significantly increased.

Abstract: A high pressure fluid jetting system generally includes a fluid cylinder pump, a drive assembly, a pressurized liquid supply and an applicator gun. The drive assembly includes a diesel engine or electric powered motor which drives a rotatable drive shaft. The drive shaft drives a triple plunger which are reciprocally driven. A valve seat assembly and a cylindrical cartridge seal assembly define a cartridge which contains a reciprocating plunger shaft. The primary high wear parts are located therein. The cartridge is retained within the manifold cartridge opening yet is readily accessible by removal of the manifold. The pump output is primarily determined by the diameter of the plunger the length of the stroke, the number of cylinders, and the speed of the pump. A specific cartridge allows replacement of all the components which interface with a plunger shaft of a predetermined diameter such that a change in pump output or repair is readily achieved by straightforward cartridge replacement.

Abstract: A reciprocating compressor including cylinder block with a plurality of cylinder bores. A piston is positioned in each bore and mounted to move in response to the a crankshaft, causing each piston to reciprocate within the cylinder bore. The compressor further includes a cylinder head, which includes bores corresponding to the bores in the cylinder block, and a suction port in fluid communication with a source of compressible gas and a plurality of suction plenum. Protrusions or ribs extend into the suction plenum. The cylinder head also includes a discharge plenum in communication with the outlet ports of the valve plate. Interposed between the cylinder head and the cylinder block is a valve plate assembly having a discharge valve, and a discharge valve retainer having a pair of radii assembled to the valve plate by snap fitting a cylinder head gasket over the discharge valve and retainer.

Abstract: A valve plate assembly includes an upper valve plate, a lower valve plate, an annular spacer and a center spacer. The annular spacer is located between the upper and lower valve plates and around the outer periphery of the upper and lower valve plates. The center spacer is located at approximately the geometric center of the valve plate assembly to provide additional support for the valve plate assembly.

Abstract: A unit for pumping fluid, particularly blood, is provided with an enclosure that has two half-shells and an elastic membrane fixed perimetrically to the enclosure in order to divide its space into two parts. One of the half-shells is provided with valves that are located at the opening of two connecting ducts for the intake and delivery of the fluid, and the other half-shell is connected to a line of working fluid that is alternately pressurized and depressurized. The first valve is a disk-shaped sheet made of elastic material. The first valve is in a central position with a support that is fixed to the opening of the first duct for connection to the outside and is suitable to rest at its peripheral region on the support. A second valve is a sheet of elastic material located at the peripheral region of the disk at the opening of the second duct for connection to the outside which lies at the peripheral region of the opening of the first duct.

Abstract: A pump (10) includes an impeller (12) positioned in a housing (11). A valve assembly (13) is positioned within a valve sleeve (25) which is carried by the impeller (12). The impeller (12) is carried by an armature (27), and a pocket (28) is formed between the impeller (12) and the armature (27) adjacent to the valve sleeve (25). One or more elastomeric members (29) are positioned in the pocket (28) to surround the impeller (12) at the area of the valve sleeve (25) to provide a retaining force on the valve sleeve (25).

Abstract: A micropump has two chambers separated by an actuator for causing fluid to flow in the chambers. Each chamber is equipped with a ball that acts as a valve for allowing flow in a desired direction. The balls are heavier than the fluid being pumped, and reside at an interface between the chambers and passages feeding fluid into the chambers and provide a tight seal between the chambers and passages feeding the chambers when fluid pressure forces the fluid back toward the feeding passages.

Abstract: A magnet pump includes a synthetic resin casing, divided into a front casing and a rear casing and configured to internally form an impeller housing chamber and a magnet can housing chamber contiguous thereto, having an inlet and an outlet for a target fluid to be transferred. The casing forms an eddy chamber at a position for dividing the front casing and the rear casing along the outer rim of the impeller housing chamber to surround the outer rim of the impeller. The eddy chamber has overhangs formed at an entry of the eddy chamber hanging over from both sides in the rotational-axis direction of the impeller.

Abstract: A hydraulic pump unit for vehicle brake control system comprising a pump housing, a cylinder received in a receiving hole formed in the pump housing. The cylinder has a bottom portion and is provided at the bottom portion with an outlet valve. A plunger is slidingly received in the cylinder and defines a pump chamber in cooperation with the cylinder. An inlet valve provided on the plunger, an inlet passage formed in the pump housing. An opening of the inlet passage is provided in the receiving hole. An outlet passage formed in the pump housing, an opening of the outlet passage is provided in the receiving hole. A plug member for closing an opening of the receiving hole, the plug member is fixed to the bottom portion of the cylinder, and an orifice plate having a passage is arranged between the bottom portion and the plug member.

Abstract: A reducing agent pump has a pump inlet part and a pump outlet part closing off the pump body at its ends. One or both of the inlet and outlet parts is of two-part construction, with a closure element and another element. The two elements are prestressed relative to one another with a spring element, so that in the event of a pressure which exceeds the spring force of the spring element, a relative movement can be carried out between the two elements of the two-part member. This makes it possible to absorb an increase in the volume of the reducing agent inside the pump body caused by freezing and therefore to prevent damage to the reducing agent pump.

Abstract: A valve plate assembly includes an upper valve plate, a lower valve plate, an annular spacer and a center spacer. The annular spacer is located between the upper and lower valve plates and around the outer periphery of the upper and lower valve plates. The center spacer is located at approximately the geometric center of the valve plate assembly to provide additional support for the valve plate assembly.

Abstract: A high pressure fluid jetting system generally includes a fluid cylinder pump, a drive assembly, a pressurized liquid supply and an applicator gun. The drive assembly includes a diesel engine or electric powered motor which drives a rotatable drive shaft. The drive shaft drives a triple plunger which are reciprocally driven. A valve seat assembly and a cylindrical cartridge seal assembly define a cartridge which contains a reciprocating plunger shaft. The primary high wear parts are located therein. The cartridge is retained within the manifold cartridge opening yet is readily accessible by removal of the manifold. The pump output is primarily determined by the diameter of the plunger the length of the stroke, the number of cylinders, and the speed of the pump. A specific cartridge allows replacement of all the components which interface with a plunger shaft of a predetermined diameter such that a change in pump output or repair is readily achieved by straightforward cartridge replacement.

Abstract: A valve for a hermetic compressor has a valve plate disposed between a cylinder block and a cylinder head. The cylinder block has a cylinder, and the cylinder head has a refrigerant suction chamber and a refrigerant discharge chamber, which are partitioned from one another by a partition. The cylinder head further has at least first, second and third plates of different thicknesses, a refrigerant suction passage for interconnecting the refrigerant suction chamber and the cylinder; and a refrigerant discharge passage for interconnecting the refrigerant discharge chamber and the cylinder. A suction valve opens and closes the refrigerant suction passage while being moved by pressure in the cylinder; and a discharge valve opens and closes the refrigerant discharge valve while being moved by the pressure in the cylinder.

Abstract: In a piston pump, in particular for pressure medium delivery in slip-controlled hydraulic brake systems, including a suction valve and a delivery valve, external preassembly and possibilities of external testing of the delivery and suction valves result from providing the suction valve and the delivery valve within a component which can be handled independently. The component preferably includes a delivery valve provided radially to the center line and a valve seat member, with a valve body of the delivery valve being prestressed by a tongue of a clamp, placed onto the valve seat member, against a valve seat formed within the valve seat member.

Abstract: A high aspiration compound valve enabling controlled fluid flow from a piston pump. It is comprised of a somewhat cylindrical housing containing a compound valve seat body creating a seal with either a suction valve or a discharge valve based upon the position of the piston's stroke within the housing. Fluid is drawn in during the down stroke of the piston through the open suction valve concentrically placed around the center housing cavity. The fluid is then pumped through the housing by the piston and utilizes a direct in-line discharge valve.

Abstract: The invention relates to a piston pump for a slip-controlled hydraulic vehicle brake system. For the sake of a short structural length of the piston pump, piston of the piston pump is a hollow piston, whose interior forms a positive displacement chamber of the piston pump. The piston can be produced economically as a reshaped part, for instance by deep drawing.

Abstract: A valve arrangement is described for providing clinical nutrition. The arrangement comprises a split flushing valve.

Abstract: In a piston pump (1), in particular for pressure medium delivery in slip-controlled hydraulic brake systems, including a suction valve (82) and a delivery valve (81), external preassembly and possibilities of external testing of the delivery and suction valves (81,82) result from providing the suction valve (82) and the delivery valve (81) within a component (8) which can be handled independently. The component (8) preferably includes a delivery valve (81) provided radially to the center line and a valve seat member (70), with a valve body (95) of the delivery valve (81) being prestressed by a tongue (121) of a clamp (120), placed onto the valve seat member (70), against a valve seat (96) formed within the valve seat member (70).

Abstract: A combination valve including a metal sleeve and a valve body. The valve body is formed of a resilient material and insert bonded or vulcanized to the metal sleeve and includes a cylindrical elongated member defining a passageway therethrough and an annular umbrella portion integrally extending from the elongated member. The elongated member is disposed within the metal sleeve and has converging flexible lips. The metal sleeve includes a plurality of prongs at one end and the valve body includes a top surface. The prongs of the metal sleeve extend to the top surface of the valve body, whereby the valve can be press-fitted into location without damaging the valve body. Between the prongs of the metal sleeve are gaps which permit the molding material to flow from the umbrella portion to the elongated member during the molding of the combination valve.

Abstract: A Y-block fluid section plunger pump housing has a cylinder bore which is transversely elongated at its intersection with suction and discharge bores to provide stress relief and a reduction in housing weight. An integral suction valve retainer arm further reduces stress near the bore intersection. Tapered cartridge packing assemblies facilitate use of a one-piece plunger in Y-block housings and also allow packing in such housings to be changed without removing the plunger.

Abstract: An axial plunger pump includes a shaft having a swash plate effecting swing motion and transmitting driving force from the outside, plungers reciprocate by the swing motion of the swash plate. A cylinder block has cylinders formed so as to open on the side of the swash plate, with the plungers inserted therein. Passages in the block supply refuel to the cylinders. A body combined with the cylinder block encloses the swash plate. Sealing members are arranged between the plungers and the cylinders on the swash plate side of the passages formed in the cylinder block for sealing gaps between the plungers and the cylinders, respectively.

Abstract: A high pressure fluid pump 10 supplies fluids to a water blasting or cutting gun 14. The pump 10 is preferably of the in-line type, wherein both an inlet check valve 60 and a discharge check valve 62 move linearly along the axis 40 of the plunger 30 during a complete pumping cycle. A plurality of compression rods 42 are spaced circumferentially about a plunger housing 24, and press the plunger housing into sealing engagement with a suction valve seat 56, press the suction valve seat into sealing engagement with a pump discharge housing 36, press the pump discharge housing into sealing engagement with a discharge end plate 38. Seal ring 66 is provided for sealing between a front planar face 114 of the suction valve seat and a rear planar face 112 of the plunger housing. A weep path 116 extends radially outward from the seal ring 66 to release fluids which pass by the compressible seal ring.

Abstract: A high pressure reciprocating pump (10) for high fluid pressures between 30,000 and 60,000 psi and having a valve cartridge (57) positioned within a manifold block (15) of the pump (10). The valve cartridge (57) has a fixed body (58) with a plurality of equally spaced suction opening (69) extending therethrough. A central bore (70) of the valve cartridge body (58) has a valve assembly (72) mounted therein. Valve assembly (72) include a discharge valve member (74) and a suction valve member (80) mounted for sliding movement about the outer surface of discharge valve member (74). A spring (84) biased between discharge valve member (74) and suction valve member (80) continuously urges the valve members (74, 80) toward closed position. On the suction stroke, suction valve member (80) is opened and fluid through suction openings (69) enters the pump chamber (37).

Abstract: A full flow tubing stationary valve pump apparatus includes an cuter annulus barrel, an inner working barrel positioned in radially inwardly spaced relation from the outer annular barrel to define a vertical flow annulus therebetween, an elongated inner plunger disposed within and vertically movable by upstrokes and downstrokes relative to the inner working barrel, a lower intake valve assembly disposed within and supported by the outer annulus barrel below the inner plunger, and an upper discharge valve assembly disposed within and supported by the outer annular barrel below the inner plunger and above the lower intake valve assembly.

Abstract: A seal assembly for a high pressure vessel. The pressure vessel can include a first material and can have a face with a bore extending through the face such that the bore has an edge at an intersection of the bore and the face. A check valve, including a second material, can extend into the bore and a seal seat, including a third material different than at least one of the first and second materials, can be positioned between the pressure vessel and the check valve body to reduce galling and/or fretting of the pressure vessel and check valve body.

Abstract: The invention relates to a piston pump for a slip-controlled hydraulic vehicle brake system. For a compact structure of the piston pump, an inlet valve and outlet valve in the form of check valves be disposed in a valve bore at a tangent to a cylinder bore of the piston pump in a pump housing. Aside from the advantage of a compact, space-saving design, the invention has the advantage of a small idle volume and thus good efficiency of the piston pump.

Abstract: An automatic pumping apparatus utilizing wave motion comprises one or more than one sink-and-float members provided so as to move up and down in accordance with a wave motion, positioned below the respective sink-and-float members, connected to the respective sink-and-float members via a transmission mechanism and adapted to slidingly move in respective one-end-open fixed cylinders in accordance with the up and down movement of the sink-and-float members, the horizontal cross sectional area of each piston being made small relative to that of each sink-and-float member and inversely proportional to the pumping height, whereby water can be pumped to a reservoir tank through pumping pipes extending from the other ends of the cylinders to positions higher than the ranges of up and down movements of the sinkand-float members by the operations of pistons.

Abstract: A high pressure fluid pump 10 supplies fluids to a water blasting or cutting gun 14. The pump 10 is preferably of the in-line type, wherein both an inlet check valve 60 and a discharge check valve 62 move linearly along the axis 40 of the plunger 30 during a complete pumping cycle. A plurality of compression rods 42 are spaced circumferentially about a plunger housing 24, and press the plunger housing into sealing engagement with a suction valve seat 56, press the suction valve seat into sealing engagement with a pump discharge housing 36, press the pump discharge housing into sealing engagement with a discharge end plate 38. Seal ring 66 is provided for sealing between a front planar face 114 of the suction valve seat and a rear planar face 112 of the plunger housing. A weep path 116 extends radially outward from the seal ring 66 to release fluids which pass by the compressible seal ring.

Abstract: A high-pressure, plunger-type liquid pump including a liquid manifold that includes a plunger chamber in the form of an axial cylindrical bore portion for slidably receiving a pressurizing plunger, and that also includes a valve chamber coaxial with the plunger chamber and in communication therewith for removably receiving a cartridge-type flow control valve. The liquid manifold includes a closure plug to close the valve chamber. The cartridge-type valve is slidably received in the valve chamber for enabling removal of the cartridge-type valve from the liquid manifold without the need for separating the liquid manifold from the pump drive housing. The cartridge-type valve is of a structure that includes in-line, axially spaced suction and discharge valves that are each spring biased into closed positions.

Abstract: A fluid pressure-intensifying apparatus of the double-acting type has end check valve assemblies (25, 25a). Each assembly has an inner low pressure poppet (100) communicable with the high pressure chamber (30) of the apparatus, and an outer high pressure ball poppet (110) communicable with a high pressure fluid outlet line (57). The check valve assembly (25) is designed for service accessibility without having to dismantle the intensifier. The apparatus includes a cylindrical housing (10) within which low and high pressure piston assemblies (28, 30, 30a) are confined by threaded end rings (12, 12a) under compression.

Abstract: There is provided a fluid side of a high pressure water pump is to be used with a pump having a power side which has at least one piston and at least one stuffing box. The fluid side consists of a unitary substantially block shaped fluid end which defines a generally cylindrical fluid inlet bore, a generally cylindrical fluid outlet bore, and at least one generally cylindrical working bore. The working bore intersects the fluid inlet bore and the fluid outlet bore. Within each working bore there is sealably provided a substantially tubular suction/discharge seat which has a longitudinal axis, a suction end, a discharge end, an outside surface extending between the suction end and the discharge end, and an inside surface extending between the suction end and the discharge end. The suction/discharge seat defines a plurality of fluid holes at the suction end which provide a flow path of a fluid from the fluid inlet bore to the inlet end of the fluid end.