Abstract: In usual hydraulic pumps, a separate assembly opening is provided for every valve of the hydraulic pump. This design causes sealing problems. It is proposed, that the fluid inlet valve (67) and the fluid outlet valve (74) can be assembled through a common assembly access port (38).

Abstract: When the fluid flow output of a synthetically commutated hydraulic pump is adapted to a given fluid flow demand, pulsations in the fluid output flow of the synthetically commutated hydraulic pump can occur. To avoid such pressure pulsations, it is suggested, to use a set of pre-calculated actuation patterns for actuating the electrically commutated valves of the synthetically commutated hydraulic pump.

Abstract: A fluid working machine (1) has several working chambers (5) of cyclically changing volume. For pumping hydraulic fluid, the inlet and outlet valves (8, 9) are electrically actuated. The timing of the actuation of said electrically actuated valves (8, 9) is varied depending on the fluid flow demand.

Abstract: To improve the fluid output flow characteristics (14) of a synthetically commutated hydraulic pump (1), it is suggested to use a plurality of different valve (10) actuation strategies. For every fluid flow demand region I to VI a certain actuation strategy is chosen.

Abstract: A chemistry analyzer precision pump is disclosed. In one general aspect, it has a pump block that defines a first pump chamber with a fluid port at a first end, an opening for a piston at a second end, and a seal mount located between the opening and the port. A second, smaller, pump chamber also has a fluid port at a first end, an opening for a piston at a second end, and a seal mount located between the opening and the port. A first seal is mounted at the first seal mount and a second seal is mounted at the second seal mount. A first piston is mounted to reciprocate in the first pump chamber, past the first seal, and a second, smaller piston is mounted to reciprocate in the second pump chamber, past the second seal. The first and second pistons and the first and second pump chambers can be conically shaped.

Abstract: Disclosed is a self-reciprocating energy recovery device utilized in driving of a seawater pump by self-reciprocating a piston of a power recovery chamber and recovering energy not using an electronic drive unit but using the hydraulic power of concentrated water. The self-reciprocating energy recovery device including a pair of power recovery chambers having pistons therein respectively, a high-pressure concentrated supply pipe, a low-pressure concentrated discharge pipe, and a high-pressure seawater discharge pipe to enable the power recovery chambers to recover hydraulic power supplied through the high-pressure concentrated water supply pipe and utilize the hydraulic power in driving of a seawater pump.

Abstract: A reed valve and a valve retainer for the reed valve are provided at a discharge port of a compression mechanism that compresses fluid. The valve retainer has a polymer actuator at an end part of a valve fixing part for fixing the reed valve. The polymer actuator expands or contracts in length to change a fixed length of the reed valve, thereby changing a rigidity of the reed valve. This attains appropriate control of responsiveness of the reed valve according to the volume.

Abstract: Power and control logic configurations for gas well dewatering systems are provided. In one example, a reservoir is configured to contain hydraulic, lubricating fluid. An electric motor is configured to receive fluid from the reservoir for lubrication and a hydraulic pump powered by the electric motor is configured to receive fluid from the reservoir and pump the fluid into a hydraulic circuit. A positive displacement oscillating pump is powered by the hydraulic pump and configured to pump fluid from the reservoir to an outlet from the well. The electric motor and hydraulic pump receive the same fluid from the reservoir for lubrication and to create pressure in the hydraulic circuit, respectively.

Abstract: An apparatus is provided and may include a compression mechanism, a valve plate including a plurality of ports in fluid communication with the compression mechanism, and a header disposed adjacent to the valve plate. A plurality of cylinders may be disposed within the header and a plurality of pistons may be respectively disposed in the plurality of cylinders and may be movable between a first position separated from the valve plate and a second position engaging the valve plate. A chamber may be disposed within each of the cylinders and may receive a pressurized fluid in a first mode to move the piston into the second position and may vent the pressurized fluid in a second mode to move the piston into the first position. One of the chambers may include a smaller volume than the other of the chambers.

Abstract: A volume chamber is formed by a valve member, an inner peripheral wall of a tubular portion and a bottom portion of a stopper when the valve member is engaged with tubular portion. A communication passage communicates between the volume chamber and one of an intermediate passage of a valve body and a tertiary passage of the stopper. The communication passage is formed at a location, which is spaced from a contact surface between the tubular portion and the valve member by a first predetermined distance and is also spaced from a contact surface between the bottom portion and the first urging member by a second predetermined distance.

Abstract: The invention relates to a control device for a hydraulic piston machine which can be embodied as a hydropump or a hydromotor and the time-averaged volume flow of which is variable. The piston machine comprises a plurality of pistons, each delimiting a working chamber the volume of which varies with the stroke of a piston and which can be connected to a high pressure port via a first valve and to a low pressure port via a second valve. At least one of the two valves of a working chamber can be actively electrically actuated. The control device comprises an electronic control unit which operates the actively actuated valves of the working chambers in a partial stroke mode, in which only a varying portion of the piston stroke is utilized.

Abstract: In a conventional configuration, a lead line weld joined portion 55 between a lead line and an end of a terminal is disposed internally of an magnetic circuit, i.e., of a yoke portion 51. This increases the total length of the magnetic circuit, i.e., the yoke portion 51 by the axial dimension of the lead line weld joined portion 55. This will increase the magnetic resistance of the magnetic circuit, which leads to a problem with a reduction in the magnetic biasing force occurring between a first core portion 33 and an anchor 35. In the present invention, the lead line weld joined portion 55 is disposed externally of the magnetic circuit, i.e., of the yoke portion 51. This eliminates the necessity of a space adapted to receive the lead line weld joined portion 55 therein; therefore, the total length of the magnetic circuit can be reduced. It is possible, thus, to generate a sufficient magnetic biasing force between the first core portion 33 and the anchor 35.

Abstract: In a reciprocating compressor with delivery rate control the actuation device (3) for the valve unloader (2) of the suction valve (1) to be held open comprises as drive an electric motor (5), whose driven element (6) in conjunction with the non-rotating lifting element (10) of the valve unloader (2) and the rolling elements (8) arranged in between forma ball screw drive. This results in a small-dimensioned, precisely to be regulated actuation device (3) with high actuating forces and with high motion dynamic.

Abstract: A pump having a housing with an actuator member positioned inside for controlling the flow generated by the pump. A first decrease port is connected to the housing and has a surface area in operable contact with the actuator member. A second decrease port is connected to the housing and has a surface area that is operable contact with the actuator member. A valve is connected to the second decrease port for controlling the flow of fluid to the second decrease port. A suction passage is connected to the housing and drawings fluid to the housing using the actuator member. A discharge passage is connected to the housing so that fluid providing an exit for fluid that has been pressurized by the actuator member.

Abstract: A high pressure pump draws fluid from a fluid inlet into a compression chamber through an inlet chamber. The high pressure pump has a fluid chamber that communicates with the fluid inlet via the inlet chamber. The high pressure pump includes a plunger and a cylinder. The plunger draws fluid from the inlet chamber into the compression chamber when the plunger moves in a drawing direction. The plunger is capable of pressurizing fluid in the compression chamber when the plunger moves in a pressurizing direction. The cylinder movably supports the plunger therein. When the plunger moves in the drawing direction, fluid in the inlet chamber is drawn into the compression chamber, so that fluid flows from the fluid chamber into the inlet chamber.

Abstract: A high pressure pump draws fluid from a fluid inlet into a compression chamber through an inlet chamber. The high pressure pump has a fluid chamber that communicates with the fluid inlet via the inlet chamber. The high pressure pump includes a plunger and a cylinder. The plunger draws fluid from the inlet chamber into the compression chamber when the plunger moves in a drawing direction. The plunger is capable of pressurizing fluid in the compression chamber when the plunger moves in a pressurizing direction. The cylinder movably supports the plunger therein. When the plunger moves in the drawing direction, fluid in the inlet chamber is drawn into the compression chamber, so that fluid flows from the fluid chamber into the inlet chamber.

Abstract: A compressor-valve modular design provides manufacturing simplicity, reduces applied cost, and improves quality and reliability of a refrigerant system. In this design, a valve is preferably an electronically controlled valve having a control member that controls the flow of a fluid through the valve. A discharge valve, a stepper motor modulation valve, an economizer vapor injection valve, a liquid injection valve or any combination of thereof are the examples of the valves within the compressor-valve subassembly.

Abstract: A bicycle air pump is basically provided with a cylinder portion, an inner piston, a piston rod, a head portion, a handle and a magnetic mechanism. The cylinder portion includes a first end, a second end and a chamber disposed between the first and second ends. The inner piston is movably disposed in the chamber of the cylinder portion. The piston rod has a first end and a second end coupled to the inner piston. The head portion is coupled to the cylinder portion. The head portion includes an outlet passage communicated with the chamber cylinder portion for supplying air to an object to be inflated. The handle is coupled to the piston rod to move within the chamber. The magnetic mechanism includes first and second closure members for engaging together magnetically to hold the piston rod stationary with respect to the cylinder portion.

Abstract: A hydraulic intensifier with a piston and cylinder assembly (1) having a first piston (3) in a chamber (4) of low pressure cylinder and a second piston (7) in a chamber (8) of a high pressure cylinder. The first and second pistons are coupled together and the first piston has a larger cross-sectional area than the second piston. A high pressure output (19) is coupled to the chamber of the high pressure cylinder, there being; means (13) for supplying low pressure hydraulic fluid to the chamber of the low pressure cylinder; an electrically operated directional control valve (11) for controlling the supply of low pressure hydraulic fluid to the chamber of the low pressure cylinder; and electronic means (14) for controlling operation of the directional control valve.

Abstract: The pump unit according to the invention is formed by assembling a pump module (9) comprising a body having a cavity (10) forming a working chamber, a translationally mobile piston (15) engaging leaktightly in the cavity (10) via a seal (14), at least one channel (12, 13) formed in the body to connect the working chamber to a use circuit, a linear actuating module comprising an actuating member (3) that is translationally mobile coaxially with the piston (15), and a connecting and guiding module (18) for establishing a mechanical connection between the pump module (9) and the linear actuating module (2) and for precise guidance of the piston (15) coaxially with the seal.

Abstract: The high pressure fluid pump includes a driver defined by a float riding on the waves of a sea surface, a fluid pump housing, an impeller operatively attached to the driver and disposed within the fluid pump housing, a backflow check system connected to the fluid pump housing, and an outflow check system controlling the pressure, volume of fluid flow, and direction of fluid flow to various other systems. The pump may be used to pump fluids other than seawater and may include features multiplying pumping mechanical advantage for a given tidal range.

Abstract: A pump apparatus includes a drive shaft supported rotatably in a pump body; a power transmission member attached to the drive shaft, and configured to transmit power to the drive shaft; a pump element configured to pressurize and discharge working fluid; a discharge passage formed in the pump body, and configured to introduce the pressurized working fluid-discharged from the pump element to an external of the pump body; a control valve configured to control an amount of working fluid to be discharged through the discharge passage to the external, by controlling a movement of a valving element of the control valve on the basis of the pressurized working fluid; and an electromagnetic valve provided between the power transmission member and the control valve, and configured to control the control valve or a fluid pressure acting on the valving element of the control valve based on the pressurized working fluid.

Abstract: Transfer pump for high-pressure petrol injection of the type comprising a piston (1) which delivers oil into a deformable element such as a bellows (8), the deformations of said bellows (8) in a cylindrical chamber (6) filled with fuel causing a pumping effect whereby said fuel is pumped towards a rail (40) supplying high-pressure injectors, wherein means are arranged for diverting some or all of the oil pumped by the piston (1) towards a chamber (15) without pressuring it so as to determine at will the useful stroke of said piston (1) and hence the quantity of fuel pumped at high pressure towards the rail (40).

Abstract: A pump includes a cylinder formed with a plunger chamber, a low-pressure portion, to which low-pressure fuel is supplied, a plunger reciprocating in the cylinder to pressurize fluid in the chamber, which is drawn from the portion, and a magnet valve having a valve body. A low-pressure passage communicates between the chamber and the portion. The magnet valve blocks the passage with the valve body when energized, to control timing, with which fluid in the chamber starts to be pressurized by the plunger. Dynamic pressure of fluid flowing from the chamber into the passage is applied to the valve body in a direction in which the valve body closes the passage. The valve body includes an inclined surface at a portion of the valve body, to which the dynamic pressure is applied. The surface is nonparallel to a plane, which is perpendicular to a displacement direction of the valve body.

Abstract: A high pressure pump has a fuel passage and a pump chamber. Fuel flows into the pump chamber through the fuel passage. The high pressure pump includes a valve member and a plunger. The valve member is movable along a movable axis in a substantially axial direction of the valve member for controlling an amount of fuel flowing into the pump chamber through the fuel passage. The plunger is movable substantially along a movable axis in a substantially axial direction of the plunger. The plunger is capable of pressurizing fuel in the pump chamber to discharge fuel in the pump chamber. The movable axis of the valve member is displaced from the movable axis of the plunger substantially in parallel with each other.

Abstract: A pump for pumping one or more media comprises a housing (1) having an actuator chamber (2) and at least one pump chamber (4). The pump chamber (4) is provided with an inlet port and an outlet port. The pump chamber (4) is delimited by a displacement member (5) which is movable to and fro between a first position and a second position. The pump further comprises a movable actuator body (3), accommodated in the actuator chamber (2) and consisting of a magnetizable or magnetic material, for driving the displacement member (5). The pump also comprises magnetic drive means (8a, 8b) for creating a magnetic field in order to move the actuator body (3). The actuator body (3) is freely movable relative to the displacement member (5) so that the displacement member (5) can be moved, by means of an impact motion of the actuator body (3), from the first to the second position.

Abstract: A fluid-working machine comprises at least one primary working chamber such as a cylinder (4) of cyclically changing volume and primary valves (7) to control the connection of the at least one chamber to low (10)- and high (9)-pressure manifolds. The machine has at least one secondary working chamber (5) of cyclically changing volume and a secondary valve (12, 21) for placing the secondary chamber in communication with the primary chamber (4) in an active state of the secondary chamber (5) and for isolating it therefrom in an idling state of the secondary chamber.

Abstract: A novel method of designing a pump by utilizing a cylinder with pistons inserted from each end. The cylinder contains two ports along the top for connection of a prime fluid chamber, a bulk fluid supply chamber and a fluid reservoir. These ports and corresponding connection details are arranged in a fashion that is perpendicular to the axis of the cylinder that comprises the pump chamber. Directly below at a different relative position also perpendicular to the axis of the pump chamber is an exit port for extrusion of fluid. The pump contains no valves or ancillary passages to direct flow between the different machine states of prime, refill, translate and dispense. The states are activated by relative position of the pistons with respect to each port. Fluid moves by translation within the pump by filling the chamber volume between the two pistons with a liquid and synchronizing the advance of the left piston with the retreat of the right piston.

Abstract: A compact air pump and valve package includes pump and valve assemblies integral with a pressure housing defining inlet ports and a plurality of fittings for connecting air lines to an interior of the pressure housing. The linear diaphragm pump assembly has a permanent magnetic shuttle mounting two diaphragms reciprocated by an electromagnet. The valve assembly has a plurality of solenoid valves disposed within the pressure housing, each solenoid valve being operable to control flow into or out of the pressure housing through an associated one of the plurality of fittings. Thus, no tubes or hoses are required to transfer air from the pump assembly to the valves. The housing has special mounts to isolate vibration arising from movement of the shuttle.

Abstract: A valve for causing pulsatile flow in a multi-piston plunger pump includes a valve poppet, a valve seat, and a spring biasing the valve poppet against the valve seat; and a mechanism holding the valve poppet in an open position, thereby producing pulsatile flow from the pump. The mechanism includes a magnet and an adjustment mechanism for moving the magnet toward and away from the valve poppet. When the magnet is moved toward the valve poppet, the magnet attracts the poppet away from the valve seat, and when the magnet is moved away from the valve poppet, the magnet releases the poppet. The spring then biases the poppet against the valve seat in a closed position.

Abstract: A valve for causing pulsatile flow in a multi-piston plunger pump includes a valve poppet, a valve seat, and a spring biasing the valve poppet against the valve seat; and a mechanism holding the valve poppet in an open position, thereby producing pulsatile flow from the pump. The mechanism includes a magnet and an adjustment mechanism for moving the magnet toward and away from the valve poppet. When the magnet is moved toward the valve poppet, the magnet attracts the poppet away from the valve seat, and when the magnet is moved away from the valve poppet, the magnet releases the poppet. The spring then biases the poppet against the valve seat in a closed position.

Abstract: A pump comprises a body for at least partially defining a pumping chamber (28); a pump member which undergoes displacement when acting upon a fluid in the pumping chamber; and a piezoelectric element which responds to the displacement of the pump member to generate an electric current. The electric current generated by the piezoelectric element is preferably applied to a charge storage device which is coupled to the piezoelectric element. The storage device can take various forms, including but not limited to a battery (50, 150, 250), a capacitor (52, 152, 252), and a power supply for the pump (54). In one example embodiment, the pump member is a diaphragm (26) which undergoes the displacement when acting upon a fluid in the pumping chamber. In this example embodiment, the piezoelectric element responds to the displacement of the diaphragm to generate the electric current.

Abstract: A piston machine includes a cylindrical wall (2) defining a swept volume (1) and having a plurality of gas inlet openings (5), and a piston (3) reciprocating in the swept volume (1), and the piston head (12) of which is formed as a valve having a plurality of openings (14) provided in the piston head (12), and a forcelocking device (16, 21; 18, 24) for retaining the plurality of openings (14) in one of their open condition and closed condition.

Abstract: A pump apparatus is provided which comprises a first displacement pump and a ceramic valve construction formed of a ceramic rotor, a ceramic stator having flat surfaces which are positioned in sealing relationship and a second displacement pump having check valves. The first displacement pump comprises a reciprocating first piston within a housing having an interior wall spaced apart from the piston. The position of the first piston and the position of the rotor are controlled to effect desired fluid flow through the stator. The first piston and a second piston of the second displacement pump are reciprocated by a common motor.

Abstract: The injection system (1) includes a pump (7) for supplying high-pressure fuel to a storage volume, defined for example by a common rail (6), for supplying a number of injectors (5). The pump (7) has at least one reciprocating pumping member (18) with a sinusoidal compression stroke (24). The injection system (1) includes at least one bypass solenoid valve (14) controlled by a control unit (16) having a chopper unit (28) for producing multiple deliveries (29, 31) at each compression stroke (24), so that the pressure in the common rail (6) is substantially level. Each pumping member (18) may be associated with a corresponding bypass solenoid valve (14).

Abstract: A pump apparatus is provided which comprises a displacement pump and a ceramic valve construction formed of a ceramic rotor and a ceramic stator having flat surfaces which are positioned in sealing relationship. The displacement pump comprises a reciprocating piston within a housing having an interior wall spaced apart from the piston. The position of the piston and the position of the rotor are controlled to effect desired fluid flow through the stator.

Abstract: Servo controlled solenoids provide actuation of a pump piston and valves, and electronic LC resonance measurements to determine liquid volume and gas bubble volume. Third order nonlinear servo control is split into nested control loops: a fast nonlinear first-order inner loop causing flux to track a target by varying a voltage output, and a slower almost linear second-order outer loop causing magnetic gap to track a target by controlling the flux target or the inner loop. The inner loop uses efficient switching regulation, preferably based on controlled feedback instabilities, to control voltage output. The outer loop achieves damping and accurate convergence using proportional, time-integral, and time-derivative gain terms. The time-integral feedback may be based on measured and target solenoid drive currents, adjusting the magnetic gap for force balance at the target current.

Abstract: A metering device that includes a housing defining a cylindrical chamber containing a reciprocating shuttle. The two opposed end parts of the chamber are interconnected by fluid flow ducts to a cylindrical valve bore. Contained with the valve is a rotary valve rod driven rotationally by a stepping motor. The valve rod has part cut away to form channels or recesses. In one rotational position of the valve rod a flow path is established from an inlet to one end of the chamber and a separate flow path is established from the other end of the chamber to an outlet. In an alternate orientation of the valve rod a flow path is formed from the inlet to the other end of the chamber and the first end of the chamber is connected to an outlet.

Abstract: A solenoid-valve-controlled fuel-injection pump for internal combustion engines, in particular diesel engines, has a solenoid valve, whose valve needle separates a high-pressure region from a low-pressure region, i.e. connects the high-pressure region and low-pressure region, in the pump housing, via a valve seat; the injection period being controlled by the opening of the solenoid valve. In addition, a low-pressure compensating piston situated in the low-pressure region is provided in order to compensate for pressure fluctuations in the low-pressure region. The exceptional feature is that the low-pressure compensating piston, which is positioned coaxially to the solenoid-valve needle, takes the form of a component part that is separate from the solenoid-valve needle. This ensures that the solenoid valve is opened unhindered and as rapidly as possible by the opening force exerted on the solenoid-valve needle by the electromagnet.

Abstract: A piezoelectrically driven fluid pump includes a chamber having two opposite sidewalls formed by flexible membranes, and an inlet and an outlet each regulated by a valve. Separate piezo elements are fixed to each of the membranes, to flex the membranes and increase or reduce the chamber volume and thereby draw fluid into the chamber or expel fluid from the chamber. The valves are each formed by two adjacent piezo elements that are supported or flexibly joined together at two opposite ends. When actuated, the valve piezo elements flex outward between the two opposite ends, opening the valve to form an aperture between the two piezo elements. In another embodiment, a fluid pump includes a chamber having one flexible membrane sidewall. A valve-regulated inlet or outlet aperture through the membrane communicates with the pump chamber. A ring-shaped piezo centered around the aperture, on the membrane, flexes the membrane.

Abstract: A radial piston pump for generating high fuel pressure in common rail fuel injection systems of internal combustion engines having a drive shaft which is rotatably supported in a pump housing and is embodied eccentrically, and having a plurality of pistons, in particular three, each disposed in a respective element bore radially relative to the drive shaft, which are movable radially back and forth in the respective element bore by rotation of the drive shaft and each define one cylinder chamber, which communicates via a suction valve with a low-pressure chamber. Precisely one suction valve is controlled such that it opens and closes as a function of the angle of rotation of the drive shaft.

Abstract: There is provided a valve opening and closing control device (10, 110, 210, 300, 410) of a type making use of a motor (12, 320), in which device the driving performance of the motor is enhanced and heat generated by constituent elements is restricted. A bridge circuit (110, 212, 382, 411) of a motor driving circuit (100, 200, 370, 400) comprises three rows of arms (113u, 113v, 113w) comprising two switching elements (111a, 111b) connected in series to each other and two diodes (112a, 112b) connected in parallel to corresponding switching elements. The respective arms are connected in parallel to an electric source (120, 213, 383, 412), and motor windings (22u, 22w, 22v) are connected to points of interconnection of the switching elements on the respective arms.

Abstract: A pump for pumping one or more media comprises a housing (1) having an actuator chamber (2) and at least one pump chamber (4). The pump chamber (4) is provided with an inlet port and an outlet port. The pump chamber (4) is delimited by a displacement member (5) which is movable to and fro between a first position and a second position. The pump further comprises a movable actuator body (3), accommodated in the actuator chamber (2) and consisting of a magnetizable or magnetic material, for driving the displacement member (5). The pump also comprises magnetic drive means (8a, 8b) for creating a magnetic field in order to move the actuator body (3). The actuator body (3) is freely movable relative to the displacement member (5) so that the displacement member (5) can be moved, by means of an impact motion of the actuator body (3), from the first to the second position.

Abstract: Disclosed is an exhaust valve capable of correctly opening/shutting an exhaust port of a cylinder based upon variation of the flux density of an electromagnet. The inventive exhaust valve may comprise a guide connected in parallel to an exhaust port of a cylinder, a needle valve provided inside the guide for opening/shutting the exhaust port while moving in cooperation with the guide. The needle valve may be controlled with an electromagnet. The invention enables complete opening of the exhaust port of the cylinder in exhaustion thereby preventing degradation of compression efficiency due to valve damage while reducing generation of vibration and noise.

Abstract: The invention relates to a device for injecting a fluid, which is at high pressure, through an injection nozzle and an externally actuated actuating device received with prestressing on a pump element. In the pump element, a control element triggerable by a magnetic actuator is received, with which high-pressure lines can be made to communicate with one another. The control element is assigned two spring means, which generate a closing force that on the high-pressure side closes the control edge of the switchable control element and/or open a control edge to a low-pressure chamber.

Abstract: A metering pump that is capable of delivering a constant, rate of fluid over a wide range of viscosities at infinitely variable delivery rates. Two identical pumping chambers are provided with one operating in the suction mode, and the other in the discharge mode with each cylinder switching modes at each pumping cycle, thereby providing continuous delivery of fluid in and out of the pump. The displacement of the chamber is large in order to facilitate operation at a very slow cycle speed of only one to four reciprocations per minute. The fluid valves are mechanically operated providing for positive sealing thus enabling the pump to operate at very slow speeds without leakage.

Abstract: A metering device for a heating appliance has a pump arrangement for the delivery of liquid that is supplied via an inlet region to an outlet region and a valve arrangement by which the pump arrangement is connected with the inlet region to receive liquid or with the outlet device to deliver liquid. The valve arrangement has a valve member that is brought into a first actuating position in which the valve member permits a liquid flow from the inlet region to the pump arrangement and prevents a liquid delivery from the pump arrangement to the outlet region. In a second actuating position the valve member prevents a liquid supply from the inlet region to the pump arrangement and permits a liquid delivery from the pump arrangement to the outlet region.

Abstract: A piston machine includes a cylindrical wall (2) defining a swept volume (1) and having a plurality of gas inlet openings (5), and a piston (3) reciprocating in the swept volume (1), and the piston head (12) of which is formed as a valve having a plurality of openings (14) provided in the piston head (12), and a forcelocking device (16, 21; 18, 24) for retaining the plurality of openings (14) in one of their open condition and closed condition.

Abstract: A diaphragm metering pump suitable for metering an effervescent gas. The pump has a pump head with a product chamber having an inlet end with a one-way inlet valve and an outlet end with a one-way outlet valve. A displaceable diaphragm member defines a boundary of the product chamber. The diaphragm member is capable of being reciprocated to cause pumping displacements. A discharge side is disposed downstream from the outlet valve. A passageway is disposed in fluid communication between the discharge side and the product chamber. A valve is disposed in the passageway. The valve is opened intermittently to allow liquid to re-enter the product chamber in an amount effective to purge gas from the product chamber to prevent loss of prime.

Abstract: A dispensing system for petrol pumps, comprising a pump, a dispensing valve in a petrol pump nozzle and an electrically controllable solenoid valve (10), characterized in that the solenoid valve (10) includes a directly acting principal valve (18) and a bypass valve (30) arranged so as to bypass the principal valve (18), and a solenoid drive (34) by which in case of a differential pressure present above the sealing seat (24) of the principal valve (18) at first only the bypass valve (30) is able to be switched to the open position, and only after a pressure compensation has, occurred at the sealing seat (24) of the principal valve (18) by the opening of the bypass valve (30) is the principal valve (18) also able to be switched to the open position.