Abstract: A pumping cassette including a housing having at least two inlet fluid lines and at least two outlet fluid lines. At least one balancing pod within the housing and in fluid connection with the fluid paths. The balancing pod balances the flow of a first fluid and the flow of a second fluid such that the volume of the first fluid equals the volume of the second fluid. The balancing pod also includes a membrane that forms two balancing chambers. Also included in the cassette is at least two reciprocating pressure displacement membrane pumps. The pumps are within the housing and they pump the fluid from a fluid inlet to a fluid outlet line and pump the second fluid from a fluid inlet to a fluid outlet.

Abstract: A liquid pump control system for dry run avoidance and re-prime detection. Pump dry run conditions can be detected with improved sensitivity by measuring pump cycle speed. Pump cycle speed is determined from sensors including pressure sensors, diaphragm end of stroke indicators, check valve movement sensors, and other techniques. A controller closes a valve to reduce pump cycle speed by reducing drive air pressure or by deadheading the pump liquid outlet. When the pump re-primes, the valve is opened, pump cycle speed increases, and pumping volume flow rate increases until a dry run condition is again encountered. Time delays can be introduced to delay shutting down or restarting the pump, for example to give a liquid source tank time to refill. The improved control sensitivity provides improved shut-down and re-start performance, reducing wear on the pump and reducing wasted drive air and energy consumption.

Abstract: Illustrative embodiments of diaphragm pumps, and pre-charging systems for use with such pumps, are disclosed. In at least one illustrative embodiment, a diaphragm pump may comprise a first diaphragm that separates a cavity into a motive fluid chamber and a pumped media chamber, a charge chamber having a controlled volume, wherein the controlled volume is adjustable to vary a controlled mass of compressed fluid capable of being stored in the charge chamber, and one or more valves configured to (i) fluidly couple the motive fluid chamber to an exhaust chamber during a first stroke period, (ii) fluidly couple the charge chamber to a compressed fluid inlet during at least a portion of the first stroke period, and (iii) fluidly couple the charge chamber to the motive fluid chamber during a second stroke period.

Abstract: In at least one illustrative embodiment, a diaphragm pump may comprise a sleeve formed to include (i) a bore extending along a longitudinal axis and (ii) a sleeve port that opens to the bore, and a spool supported in the bore of the sleeve and formed to include a spool port, the spool being configured to move with a diaphragm during at least a portion of a stroke of the diaphragm such that the spool slides relative to the sleeve and, when the diaphragm reaches a turndown position that is between first and second end-of-stroke positions, the spool port aligns with the sleeve port to cause a pilot signal to be supplied to a cut-off valve. At least one of the sleeve and the spool may be rotatable about the longitudinal axis to adjust a location of the turndown position relative to the first and second end-of-stroke positions.

Abstract: A pump system for producing fluids from a reservoir using a wellbore having a vertical section with a casing defining an annulus, a transitional section and a horizontal section, and a production tubing having a vertical section and a horizontal section, wherein the system includes a completion with an isolation device in the annulus near the bottom of the vertical section, a gas/liquid separator for receiving produced fluids from the horizontal section, and a vertical lift pump; a continuous flow path from the terminus of the production tubing to the vertical section; a plurality of horizontal pumps in the horizontal section, each having an intake exposed to the reservoir and an outlet in the continuous flow path. The horizontal length of the production tubing is closed to the reservoir except through the horizontal pumps.

Abstract: A pumping cassette, the cassette includes a housing. The housing includes at least one fluid port and at least one air vent port. The air vent port vents a fluid source outside the housing. The pumping cassette also includes at least one reciprocating pressure displacement membrane pump within the housing. The pump pumps fluid.

Abstract: A hydraulically-controlled diaphragm pump including a pump chamber formed between a pump head and a pump body, a constant volume intermediate hydraulic chamber formed in the pump body and including a piston driven with reciprocating motion inside the intermediate chamber, a leak compensation volume for compensating leaks from the intermediate chamber being connected thereto by a top-up channel via a free check valve that is not rated and that passes fluid towards the working chamber. The check valve and at least a portion of the compensation volume are housed in a body fitted to the pump body at the high point of the intermediate hydraulic chamber in the working position of the pump.

Abstract: Reciprocating positive-displacement membrane pumps (which may be referred to hereinafter as “pods,” “pump pods,” or “pod pumps”) used to pump fluids, such as a biological fluid (e.g., blood or peritoneal fluid), a therapeutic fluid (e.g., a medication solution), or a surfactant fluid are disclosed. The speed of a pump stroke can be adjusted by altering a frequency of pressure pulses delivered to the pump membrane during a fill stroke or a delivery stroke of the pump. A pumping algorithm may divide a pump stroke into an initial pumping period and a end-of-stroke pumping period, with the pressure pulse duration being longer during the initial pumping period. This arrangement may allow for a minimum pump flow rate while also providing a pressure ripple that can be used to detect the end of a pump stroke.

Abstract: A central flow double diaphragm pump controlled by an operating fluid distribution module with a pivoting sealing member and protruding wing, that pivots on a low friction seal. The pump also includes a central pump body having an inlet and discharge manifolds, and two pumped fluid chambers in the central pump body each including a pumped fluid chamber inlet port and outlet port; within each chamber the inlet port is positioned higher than the outlet port. Two suction check valves are located in the central body, close to the suction inlet, above the pump's shaft, and these valves' outlets connect directly to the pumped fluid chamber inlet ports. Two discharge check valves are located in the central pump body, close to the discharge outlet and below the shaft, and the pumped fluid chamber outlet ports connect directly to these valves' inlets. Removable access caps are included above the check valves.

Abstract: A diaphragm pump (10) having a pump body (11) providing opposing pump chambers (12, 13). Mounted in the body is a piston assembly (14) having pistons (15) joined by a piston rod (16). Each piston (15) is sealingly connected to the body (11) by a diaphragm (22) so that each of the chambers (12, 13) is divided into a first and a second sub-chamber, with the flow of fluid being pumped is governed by a pair of valves (30). Each valve (30) includes a base (31) to which there is movably attached a movable valve member (35).

Abstract: A pumping system comprising a membrane pump (1) for pumping a medium into or out of a vessel (6), the membrane pump comprising an actuating member (13) for moving a membrane (3) in a first direction from a first end position to a second end position against the action of a spring (12), the membrane being movable in the opposite direction from the second end position to the first end position under the action of the spring. The pumping system comprises sensing means (14) for generating a measuring value representing the location of said first end position of the membrane (3), and processing means (17) for establishing a pressure value representing the pressure inside a vessel (6) connected to an inlet (5) or outlet (24) of a pump chamber (4), the processing means (17) being adapted to establish said pressure value based on said measuring value.

Abstract: An undulating diaphragm pump having a propulsion chamber for receiving said diaphragm, wherein the diaphragm has mechanical characteristics that vary from an inlet of the propulsion chamber towards an outlet of the propulsion chamber in such a manner that, when the diaphragm is actuated to deform with a traveling wave that propagates from the inlet towards the outlet of the propulsion chamber in order to propel the fluid, the propagation speed of the wave in the diaphragm in any cross-section relative to the movement of the fluid inside the propulsion chamber is equal to or greater than the mean travel speed of the fluid in said section.

Abstract: A pump includes a housing defining an interior volume, a diaphragm partitioning the interior volume into a pumping chamber and an actuating chamber, a diaphragm support associated with the actuating chamber and configured to limit movement of the diaphragm, and a dispersion element coupled to the housing. The dispersion element is configured to laterally distribute a fluid within the pump.

Abstract: Illustrative embodiments of positive displacement pumps utilizing pressure compensating calibration, as well as related systems and methods, are disclosed. In one illustrative embodiment, a method of operating a positive displacement pump includes sensing, with a pressure sensor disposed at a fluid outlet of the positive displacement pump, a back pressure at the fluid outlet, transmitting a pressure signal associated with the sensed back pressure from the pressure sensor to a controller of the positive displacement pump, and identifying, on the controller, a volume of fluid pumped by the positive displacement pump using the pressure signal.

Abstract: Illustrative embodiments of diaphragm pumps having an automatic priming function, as well as related systems and methods, are disclosed. In one illustrative embodiment, a method of priming a diaphragm pump includes sensing, with a pressure sensor disposed at a fluid outlet of the diaphragm pump, a pressure of a fluid being pumped by the diaphragm pump, transmitting a pressure signal associated with the sensed pressure from the pressure sensor to a controller of the diaphragm pump, and identifying, on the controller, whether the diaphragm pump is primed by determining whether a characteristic of the pressure signal has reached a threshold.

Abstract: One or more techniques and/or systems are disclosed for increasing compressed air efficiency in a pump that utilizes an air efficiency device in order to optimize the amount of a compressed air in the pump. The air efficiency device may allow for controlling the operation of the air operated diaphragm pump by reducing the flow of compressed air supplied to the pump as the pump moves between first and second diaphragm positions. A sensor may be used to monitor velocity of the diaphragm assemblies. In turn, full position feedback is possible so that the pump self-adjusts to determine the optimum, or close to optimum, turndown point of the diaphragm assemblies. As such, air savings are achieved by minimizing the amount of required compressed air.

Abstract: A diaphragm vacuum pump has an electrically operated drive unit and a vacuum diaphragm, which separates a pump chamber into a drive-side part and a drive-remote part and which can be deflected by means of a movable part of the drive unit. The drive unit is an electromagnetic drive unit and the vacuum diaphragm is deflected in the direction of a linear movement generated electromagnetically in the drive unit. Preferably, a ventilation valve is also actuated the movable part. The vacuum pump is relatively small and compact and operates quietly. The vacuum pump is suitable in particular for “hands-free” applications of breastpumps.

Abstract: A peritoneal dialysis (PD) system that includes a disposable PD cassette including a base having a substantially planar portion and a dome-shaped protrusion extending from the substantially planar portion and a flexible membrane attached to the base and covering a recessed region of the dome-shaped protrusion to form a pumping chamber between the flexible membrane and the recessed region of the dome-shaped protrusion. The system also includes a PD machine including a deck and a door hinged from one side to the deck. The door and the deck can cooperate to form a cassette compartment, and the door has a cylindrical recess positioned to receive the dome-shaped protrusion of the base of the disposable PD cassette when the disposable PD cassette is disposed in the cassette compartment and the door is closed.

Abstract: Plastic microfluidic structures having a substantially rigid diaphragm that actuates between a relaxed state wherein the diaphragm sits against the surface of a substrate and an actuated state wherein the diaphragm is moved away from the substrate. As will be seen from the following description, the microfluidic structures formed with this diaphragm provide easy to manufacture and robust systems, as well readily made components such as valves and pumps.

Abstract: An method and apparatus for disbursing a pressurized liquid in the absence of electricity are disclosed. The method and apparatus for disbursing a pressurized liquid in the absence of electricity can include a gas source, a liquid source, a liquid pressurization system, and a liquid delivery system.

Abstract: A product delivery mechanism for a beverage dispensing system that dispenses flavor/ingredients and ice into a serving cup for mixing and/or blending. The product delivery system includes a gas operated pump for moving the flavor/ingredients from a product source to a dispensing nozzle above the serving cup. A gas restrictor is connected to an exhaust port of the pump to regulate gas flow rate and product flow rate so as to prevent splashing at the cup while operating the pump well within its rated pressure limits.

Abstract: A damper assembly for a fuel pump includes at least one diaphragm assembly formed by joining two metal diaphragms to respective two sides of an imperforate central plate, thereby creating a pair of closely spaced diaphragms, each acting upon its own gas volume. Preferably, the diaphragm assembly has (a) a rigid, relatively thick circular or polygonal central plate, (b) a first circular diaphragm having a rim portion sealingly secured as by welding to the plate and a relatively thin, flexible, convex portion projecting from one side of the plate and defining a first pressurized gas volume, and (c) a second circular diaphragm having a rim portion sealingly secured as by welding to the plate and a relatively thin, flexible, convex portion projecting from the other side of the plate and defining an independent second pressurized gas volume.

Abstract: The invention refers to a housing (1) with a housing axis (8) and two housing parts (2, 3) mane of plastic, and with a joint extending between them transversally to the housing axis, in which case the housing parts (2, 3) are braced against one another with the help of at least one connecting element (7) made of plastic firmly bonded to the housing parts (2, 3), with a force (F) acting along the housing axis (3) of the housing (1).

Abstract: A piezoelectric micro-blower capable of efficiently conveying compressive fluid without use of a check valve and ensuring a sufficient flow rate. The micro-blower has a blower body with a first wall and a second wall. Openings are formed in the respective walls and face a center of a diaphragm. An inflow path allowing the openings to communicate with the outside is formed between the walls. By applying a voltage to a piezoelectric element to cause the diaphragm to vibrate, a part of the first wall close to the first opening vibrates. Thus, gas can be drawn from the inflow path and discharged from the opening in the second wall.

Abstract: The present invention relates to a separation type pneumatic dual partition membrane pump, which comprises a pump body and an external pneumatic control valve which is separately installed. Through the operation of the external pneumatic control valve, the main shaft of the pump body and the valve rod of the external pneumatic control valve are reciprocally moved, and the two partition membranes respectively generate stretch and compress motions for changing the volume of each liquid room in the pump body so as to perform the pump stroke and the liquid suction stroke to the liquid.

Abstract: Plastic microfluidic structures having a substantially rigid diaphragm that actuates between a relaxed state wherein the diaphragm sits against the surface of a substrate and an actuated state wherein the diaphragm is moved away from the substrate. As will be seen from the following description, the microfluidic structures formed with this diaphragm provide easy to manufacture and robust systems, as well readily made components such as valves and pumps.

Abstract: One or more techniques and/or systems are disclosed for increasing compressed air efficiency in a pump utilizes an air efficiency device in order to optimize the amount of a compressed air in a pump. The air efficiency device may allow for controlling the operation of the air operated diaphragm pump by reducing the flow of compressed air supplied to the pump as the pump moves between first and second diaphragm positions. A sensor may be used to monitor velocity of the diaphragm assemblies. In turn, full position feedback is possible so that the pump self-adjusts to determine the optimum, or close to optimum, turndown point of the diaphragm assemblies. As such, air savings is achieved by minimizing the amount of required compressed air.

Abstract: A conveying unit for conveying reducing agent from a tank to an exhaust gas treatment device for treating the exhaust gases from an internal combustion engine, includes a pump having a drive or drive unit and a pump chamber unit or containment. The pump chamber unit or containment at least partly delimits a pump chamber and the drive or drive unit and the pump chamber unit or containment are detachable from one another.

Abstract: A pump includes a housing defining an interior volume, and a diaphragm, where the diaphragm partitions the interior volume into a pumping chamber and an actuating chamber. The diaphragm is formed from a polymeric material, and the pump further includes a diaphragm support configured to limit a stroke of the diaphragm. The diaphragm support includes an array of apertures through which fluid passes to interface with the diaphragm during operation of the pump.

Abstract: A pump for one or more different process fluids is provided including a pumping chamber having a process fluid inlet and outlet coupled to a process fluid valve on each pumping chamber for selectively preventing and allowing flow of process fluid through the pumping chamber. An actuation mechanism for pumping actuating fluid to actuating fluid chambers is provided that is in communication with the actuating fluid chambers to permit flow into each actuating fluid chamber of incompressible actuating fluid. A diaphragm separates each pumping chamber from an associated actuating fluid chamber for separating process fluid from actuating fluid. The actuation mechanism is removable by a quick disconnect that provides for disconnection of the activation mechanism without affecting process fluid. Operation of the actuation mechanism to displace actuating fluid causes actuating fluid to flow only into each actuating fluid chamber having an opened process fluid valve, resulting in pumping.

Abstract: A highly precise and extremely compact metering unit for fluid media has a pump, two valves, and a fluid communication base with two ports, pump and valve channels, and a pump chamber. The pump is mounted on the pump chamber. The pump channels communicate with the pump chamber and the valves. The valve channels communicate with the valves and the ports. The pump and the two valves are arranged one beside the other on the same side of the fluid communication base.

Abstract: The invention is a hydrogen generator including a pump for pumping a liquid from a reservoir to a reaction area, where the liquid reacts to produce hydrogen gas, and a fuel cell system including the hydrogen generator and a fuel cell stack. The pump is a diaphragm pump with mechanically operated liquid inlet and outlet valves that are opened by cam-operated pushrods, and the pushrods are isolated from the liquid flowpath through the pump by diaphragms. All valves in the liquid flow path between the liquid reservoir and the reaction area are mechanically operated valves.

Abstract: A pump that has a cavity (13) in which is located a non-elastomeric membrane (14). An inlet (24) opens into the cavity (13) and is associated with a valve (27). A valve (28) is likewise provided in an outlet (25). Also opening into cavity (13) is a port (22) to which a negative or positive pressure can be applied whereby the membrane (14) can be moved between its two stable states corresponding to completion of inlet and exhaust of a pumping cycle.

Abstract: Miniature pumps for dispensing a volume a flowable substance are described. One pump embodiment includes an environmentally-responsive plug layer that can contract in size, e.g., when exposed to an environmental change such as temperature, to allow an activation solution to flow to a layer of expandable material, such as a superporous hydrogel. Expansion of the expandable material urges a diaphragm into a chamber that holds the dispensable fluid, gas, or gel, forcing the fluid, gas or gel out of the pump.

Abstract: A pump for one or more different process fluids is provided including a pumping chamber having a process fluid inlet and outlet coupled to a process fluid valve on each pumping chamber for selectively preventing and allowing flow of process fluid through the pumping chamber. An actuation mechanism for pumping actuating fluid to actuating fluid chambers is provided that is in communication with the actuating fluid chambers to permit flow into each actuating fluid chamber of incompressible actuating fluid. A diaphragm separates each pumping chamber from an associated actuating fluid chamber for separating process fluid from actuating fluid. The actuation mechanism is removable by a quick disconnect that provides for disconnection of the activation mechanism without affecting process fluid. Operation of the actuation mechanism to displace actuating fluid causes actuating fluid to flow only into each actuating fluid chamber having an opened process fluid valve, resulting in pumping.

Abstract: Plastic microfluidic structures having a substantially rigid diaphragm that actuates between a relaxed state wherein the diaphragm sits against the surface of a substrate and an actuated state wherein the diaphragm is moved away from the substrate. As will be seen from the following description, the microfluidic structures formed with this diaphragm provide easy to manufacture and robust systems, as well readily made components such as valves and pumps.

Abstract: A high-pressure pump has an elastic member arranged in a damper chamber between a first diaphragm and a second diaphragm. The elastic member is always in contact with both diaphragms while the high-pressure pump is operated. When the diaphragms are further vibrated due to a resonance under a situation where a frequency of the pressure pulsation of low-pressure fuel is in agreement with the characteristic frequency of the diaphragms, the elastic member restricts the deformation of the diaphragms. Therefore, the resonance of the first diaphragm and the second diaphragm can be restricted.

Abstract: A damper assembly for a fuel pump includes at least one diaphragm assembly formed by joining two metal diaphragms to respective two sides of an imperforate central plate, thereby creating a pair of closely spaced diaphragms, each acting upon its own gas volume. Preferably, the diaphragm assembly has (a) a circular or polygonal central plate, (b) a first circular diaphragm having a rim portion sealingly secured as by welding to the plate and a relatively thin, flexible, convex portion projecting from one side of the plate and defining a first pressurized gas volume, and (c) a second circular diaphragm having a rim portion sealingly secured as by welding to the plate and a relatively thin, flexible, convex portion projecting from the other side of the plate and defining an independent second pressurized gas volume. The diaphragm assembly can be supported radially inside, outside, or on the weld.

Abstract: The present invention relates to a liquid channel device capable of easily opening the liquid channel from the closed mode, including a base plate in which a liquid channel, through which a liquid containing at least one of a sample and a reagent, flows, and a metering chamber for holding the liquid, are formed to at least one side thereof, the metering chamber has a liquid transport section for transporting the liquid inside the chamber downstream, and this liquid transport section is operated by means of external pressing on a cover plate in the area opposite the metering chamber.

Abstract: The present invention relates to pump systems and engine systems having graphene drums. In embodiments of the invention, the graphene drum can be utilized in the main chambers and/or valves of the pumps and engines.

Abstract: A diaphragm assembly for a fluid driven diaphragm pump includes a piston having an inflexible core. This core includes a hub with a plate extending radially from about the periphery of the hub. The piston further includes a unitary diaphragm body molded with the inflexible core in situ. The unitary diaphragm body has a plurality of connective tendons extending through the plate. A thermoplastic coating extends about the inflexible core between the core and the molded unitary diaphragm body having a thermally miscible surface with the thermoplastic coating. An inflexible backing plate extends in juxtaposition with the diaphragm.

Abstract: A device for detecting breaks in a diaphragm of a hydraulically-actuated pump includes a body (21) in which a first chamber (22) is formed, a duct (23) connecting the first chamber to a second end of the body, a check valve (24) arranged in the duct to pass fluid from the second end towards the first chamber, a piston (26) having a first portion (27) that co-operates in sealed manner with the first chamber and that has a hole passing therethrough of diameter greater than the diameter of a free ball (25) of the check valve, and a second portion (33) that is suitable for co-operating in sealed manner with the first portion to form a closed end of the piston. A method of mounting such a device on a pump, and a pump fitted with such a device, are also provided.

Abstract: A method for increasing compressed air efficiency in a pump utilizes an air efficiency device in order to optimize the amount of a compressed air in a pump. The air efficiency device may allow for controlling the operation of the air operated diaphragm pump by reducing the flow of compressed air supplied to the pump as the pump moves between first and second diaphragm positions. A sensor may be used to monitor velocity of the diaphragm assemblies. In turn, full position feedback is possible so that the pump self adjusts to determine the optimum, or close to optimum, turndown point of the diaphragm assemblies. As such, air savings is achieved by minimizing the amount of required compressed air.

Abstract: The pump includes a piston slidably mounted in a metering chamber, the piston including a support, a diaphragm made of a first material and forming a check valve that allows fluid to flow into the metering chamber, and a presser element for pressing the diaphragm against the support, the presser element including a skirt carrying seal enabling the piston to slide in leaktight manner in the metering chamber, the presser element being made of a second material different from the first material of the diaphragm, being fitted against the diaphragm, and having a diaphragm presser surface that holds the diaphragm deformed against the support in order to close the check valve.

Abstract: A valve body for pumps has a compressed air-filled chamber in the center thereof and a compressed air supply port through which compressed air is supplied into the compressed air-filled chamber. The outer surface of the valve body is provided with an annular groove-shaped air supply chamber that communicates between the compressed air-filled chamber and a pump-side air chamber. Compressed air supplied into the compressed air-filled chamber through the compressed air supply port is supplied into the pump-side air chamber through the air supply chamber.

Abstract: A double-diaphragm pump includes a pair of axially spaced apart pumping chambers, each chamber having a pumping diaphragm which divides each chamber into an inner and outer compartment. Inner ends of both pumping chambers are closed by a central element, and fluid is supplied to the outer compartments to cause the diaphragms to oscillate and vary the capacities of the inner compartments. I Each of the inner compartments having an inlet and an outlet port leading to unidirectional valves to allow fluid to be drawn into one of the compartments when the appropriate diaphragm moves outwardly and expelled from that compartment when the diaphragm moves inwardly. The unidirectional valves are located in inlet and outlet manifolds in the central element and are accessed and fitted through the inlet and outlet ports in the inner compartments.

Abstract: A pump that has a cavity (13) in which is located a non-elastomeric membrane (14). An inlet (24) opens into the cavity (13) and is associated with a valve (27). A valve (28) is likewise provided in an outlet (25). Also opening into cavity (13) is a port (22) to which a negative or positive pressures can be applied whereby the membrane (14) can be moved between its two stable states corresponding to completion of inlet and exhaust of a pumping cycle.

Abstract: A fluid transporting device is provided with a pump chamber that has a pump function for sucking and discharging a fluid, and is filled therein with the fluid, a casing unit which forms one portion of a wall surface of the pump chamber, a diaphragm which is formed by a conductive polymer film that is subjected to electrochemomechanical expansion and contraction, and forms one portion of the wall surface of the pump chamber, an electrolyte chamber that contains an electrolyte therein, with one portion of the electrolyte being made in contact with the diaphragm, a power supply that applies a voltage to the diaphragm, and a pressure maintaining unit that maintains a pressure of the diaphragm within a predetermined range by moving or deforming the one portion of the wall surface of the electrolyte chamber.

Abstract: A hydraulically driven reciprocating pump. In some embodiments, the pump includes a housing including a hydraulic chamber, a cylinder coupled to the housing, a piston assembly adapted for reciprocal motion within the housing and the cylinder, the piston assembly separating the hydraulic chamber into three subchambers, and a hydraulic system fluidicly coupled to each of the subchambers. The hydraulic system is actuatable to deliver hydraulic fluid to a first of the subchambers, whereby the piston assembly strokes back and a working fluid is drawn into the cylinder, to deliver hydraulic fluid to a second of the subchambers, whereby the piston assembly strokes out and the working fluid is exhausted from the cylinder, and to adjust a volume of hydraulic fluid within a third of the subchambers, whereby the piston assembly translates to bring a pressure of the working fluid in the cylinder to within a pre-selected range.

Abstract: Apparatus for a pump assembly and a fluid metering unit. The pump assembly can include a diaphragm with a portion of a body being molded over a portion of each one of a plurality of pistons. The pump assembly can include a wobble plate, a lower housing, and a spring positioned between the wobble plate and the lower housing. A valve housing can include pumping chambers with side walls that are angled. The fluid metering unit can include a bayonet locking mechanism and/or a seal between a housing and a flow meter. The controller can be calibrated according to the type and/or temperature of the fluid.