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 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: Piston systems comprise a housing including a first piston chamber and a second piston chamber therein. A first piston is movably disposed within the first piston chamber and a second piston is movably disposed within the second piston chamber. A flow path extends between and couples the first piston chamber and the second piston chamber. Reciprocating pumps comprising a flow path between a plurality of piston chambers and methods of driving reciprocating pumps are also disclosed.

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 air logic controller for increasing the efficiency of an air operated double diaphragm pump. The air logic controller may increase the efficiency of the pump by controlling the supply of compressed fluid to the pump. In one embodiment, the air logic controller may control the supply of compressed fluid to the pump by replacing the continuous, large volume supply of compressed fluid supplied to conventional air operated pumps during a single pumping stroke with a varied supply of compressed fluid. The varied supply of compressed fluid may comprise a supply of compressed fluid that alternates between a large volume supply and a small volume supply of compressed fluid. The air logic controller may vary the supply of compressed fluid to the pump based at least partially on the position of a main air valve spool and the setting on an adjustable pneumatic time delay relay.

Abstract: An air operated double diaphragm pump comprising an air valve mechanism. The air valve mechanism may comprise a single valve system that replaces the two valve system found in conventional air operated double diaphragm pumps. The position of the valve may be determined by the diaphragm motion of the pump up to a stall position. A spring-loaded mechanical actuation may complete the valve action from the stall position to the final or end of stroke position of the pump.

Abstract: With the waste container washing system described herein, the waste container can be moved into a washing compartment of the washing vehicle for washing thereof; in a first washing phase, the waste container can be exposed to a plurality of water jets of grey water pumped from a grey water reservoir; and in a second washing phase, the waste container can be exposed to a plurality of clean water pumped from a clean water reservoir. The water used in the first and/or second washing phase can be collected and stored in the grey water reservoir. Other improvements, such as a double-action pump for the two phases, a filtering system for grey water, a container movement system and path, and methods are also described.

Abstract: A multiphase pump includes a master cylinder having a first port adjacent to a first end of the master cylinder, and a second port adjacent to a second end of the master cylinder connected to a source of hydraulic fluid. A master piston is positioned within the master cylinder. A slave cylinder is adjacent to each of the first and second ends of the master cylinder. Each slave cylinder has a first input port and a first output port adjacent to a first end of each slave cylinder, and a second input port and a second output port adjacent to a second end of each slave cylinder. Each first input port and second input port is adapted to connect to a source of gas to be compressed. A slave piston is positioned within each slave cylinder and is connected to the master cylinder such that movement of the master piston results in movement of each slave piston.

Abstract: A valve assembly includes first and second conduits having respective first and second flanges in abutment with each other, a stopper in the second conduit, and a valve body secured between the first and second flanges. The valve body includes a body bore in communication between the first and second conduits. The body bore defines a circular opening in one end of the valve body. The valve body also includes a circumferential notch that substantially insulates the circular opening from distortion arising from securing the valve body. The stopper snuggly seats against the circular opening to prevent fluid flow from the second conduit to the first conduit, but unseats to permit fluid flow from the first conduit to the second conduit. An o-ring may surround a portion of the valve body and be energized as the valve body is secured. A lip may surround the circular opening to provide a seat for the stopper.

Abstract: A fluid pump assembly is disclosed for performing in a damp environment. A pump member is provided that drives a quantity of fluid. A pump housing encloses the pump member and includes a breather hole for circulating cooling air around the pump member during operation. A cover is provided that substantially covers the breather hole and defines a tortuous path that enables air to circulate through the breather hole while preventing entry of water thereto.

Abstract: A pump assembly includes a housing defining a working chamber, a water pump chamber and a waste pump chamber. A first diaphragm separates the water pump chamber and the working chamber. A second diaphragm separates the waste pump chamber and the working chamber. A common driver member interconnects the first diaphragm and the second diaphragm. Movement of the driven member to a first position creates a positive pressure in the water pump chamber and a negative pressure in the waste pump chamber. Movement of the driven member to a second position creates a negative pressure in the water pump chamber and a positive pressure in the waste pump chamber.

Abstract: A pump for use in handling one or more different process fluids includes a plurality of pumping chambers having a process fluid inlet and a process fluid outlet, process fluid outlet coupled to a process fluid valve on each pumping chamber for selectively preventing and allowing the flow of process fluid through the pumping chamber, an actuation mechanism for pumping actuating fluid to a plurality of actuating fluid chambers in fluid communication with the actuating fluid chambers to permit flow into each actuating fluid chamber of actuating fluid, and at least one diaphragm separating each pumping chamber from an associated actuating fluid chamber, for separating process fluid from actuating fluid. Operation of the actuation mechanism displaces actuating fluid and causes actuating fluid to flow only into each of the actuating fluid chambers having an opened process fluid valve, resulting in pumping.

Abstract: Reciprocating pumps are disclosed. Particularly, reciprocating pumps including pressure chambers and fluid chambers defined by flexible members are disclosed. The volume of the pressure chambers and fluid chamber may be controlled using a piston driven by the flow of a control fluid to a pressure chamber and associated piston chamber. The flow of the control fluid may be directed to a first pressure chamber and associated piston chamber or a second pressure chamber and associated piston chamber. A pneumatically driven switch or an electrically driven switch may direct the flow of control fluid. The electrically driven switch may be controlled with a timer, a pressure sensor, or an optical sensor. The reciprocating pump requires minimal modification to permit the use of a pneumatic switch or electrical switch.

Abstract: A hydraulic automatically-pressurizing pump comprises an intermediate fastening connector, a reversing valve, a mechanically-controlled automatic direction-reversing device, a power cylinder, a pressurizing cylinder and an ultrahigh-pressure connecting tube which are disposed in series in a case and assembled from the upper end to the lower end along a central axes of the case. The fastening connector is connected with the case and further connected through pressure with the reversing valve. The power cylinder is a multi-stage power cylinder. The pressurizing cylinder communicates with a two-channel drill bit through the ultrahigh-pressure connecting tube, and an ultrahigh-pressure channel is provided on the wall of the pressurizing cylinder. The core of the reversing valve is connected with the mechanically-controlled automatic direction-reversing device.

Abstract: A valve for a gas-driven motor and a valve assembly and reciprocating pump incorporating the valve are provided. The valve includes a shiftable valve for alternatively supplying a motive gas through first and second supply ports to opposed first and second power pistons in opposed motive gas chambers, respectively, and for effecting alternating exhaust of said chambers. The shiftable valve has a front face with a valve projection located thereon and a rear face with a valve projection located thereon.

Abstract: An internal combustion engine fuel pump having at least one cylinder, in which a variable-volume pump chamber is defined; a movable piston defining the bottom of the pump chamber; at least one intake valve communicating with the pump chamber; at least one delivery valve communicating with the pump chamber; and a hydraulic/pneumatic actuating device for moving the piston back and forth with respect to the cylinder to cyclically vary the volume of the pump chamber; the hydraulic/pneumatic actuating device has a first actuating chamber located beneath the pump chamber, a second actuating chamber located above the first actuating chamber, and a control member for cyclically filling the first actuating chamber with pressurized oil.

Abstract: A pressure exchange device is provided that utilizes an integral high pressure boost pump that is in fluid communication with a pressure exchange unit. An optional low pressure boost pump unit may also be provided. The pressure exchange unit comprises a rotating rotor assembly inside a housing to transfer the pressure of a fluid from one high pressure fluid to another low pressure fluid.

Abstract: A pump for pressurizing a fluid includes an engine portion including a first pressure vessel, a first piston movable inside the first pressure vessel, at least two pressurant entrance valves connected to the first pressure vessel, and at least two pressurant exit valves connected to the first pressure vessel. The valves are configured to be opened and closed automatically and directly as a function of a position of the first piston inside the first pressure vessel. The valves are also configured to be automatically opened and closed out of phase with each other. The pump also includes a pump portion including a second pressure vessel, a second piston connected to the first piston and movable inside the second pressure vessel, at least two fluid entrance valves connected to the second pressure vessel, and at least two fluid exit valves connected to the second pressure vessel.

Abstract: A system to intensify pressure supplied by a conventional pump where a piston assembly having two piston members at opposite ends is positioned in a pressure cylinder. The laterally outer subchambers are defined by the piston members and the cylinder and are adapted to receive fluid at an operating pressure provided by the pump and produce intensified pressure at the opposite outer subchamber. A pressure distributing system alternates returning fluid at intensified pressure to the inner subchamber near the outer subchamber creating the intensified pressure.

Abstract: A pressurizer for pressurizing a fluid includes: at least two storage tanks, where, for each storage tank, the pressurizer further includes: a propellant entrance valve, a propellant exit valve, a pressurant entrance valve, and a pressurant exit valve, where each of the storage tanks is configured to be filled with the fluid under a low pressure when its propellant entrance and pressurant exit valves are open and its propellant exit and pressurant entrance valves are closed, and to be drained of the fluid under a high pressure by the force of a pressurant when its valves are reversed, where its valves are configured to be opened and closed in a cycle to sequentially fill and drain the storage tank of the fluid, the cycle having a cycle time of between 1 and 500 milliseconds, and where the cycles of the valves of the storage tanks are out of phase with each other such that at some time in which one storage tank is being filled with the fluid, at least one other storage tank is being drained of the fluid.

Abstract: A pneumatic oscillator for providing pumping force to a pump. The oscillator has a single valve for controlling both the rate of oscillation of the oscillator and the flow of air. The valve includes a shuttle member and a detent mechanism. The detent mechanism controls the air flow in the oscillator and to the pump to which the oscillator is attached and the detent mechanism for regulating oscillation of the shuttle member. The configuration of the shuttle member and the detent mechanism eliminates the need for an additional valve to regulate oscillation of the oscillator. A cycle controller corresponding with the detent mechanism is adapted to change the rate of oscillation of shuttle member such that the need for additional valves or controllers for regulating the rate of oscillation is obviated.

Abstract: The invention relates to a pneumatic open- and closed-loop control apparatus (10) for flows of pressure fluid, having one inlet conduit (14), two outlet conduits (16, 18), and one venting conduit (20), and also having a valve piston (90) mediating between these conduits and mounted in a valve chamber (92), and to a method for open- and closed-loop control of flows of pressure fluid. It is proposed that by means of a pneumatically driven valve piston (92), with a predeterminable time constant, one outlet conduit (16, 18) each of the pneumatic open- and closed-loop control apparatus (10) is connected to the single inlet conduit (14), while the other outlet conduit is simultaneously connected to the venting conduit (20).

Abstract: A fluid driven pump. One embodiment of the fluid driven pump may include first and second diaphragms supported within a housing assembly such that first and second fluidtight expansion chambers are defined within the housing. The pump may have a first exhaust valve movably supported in a first exhaust valve cavity in fluid communication with the first expansion chamber and an exhaust port in the housing assembly. In addition, the pump may have a second exhaust valve movably supported in a second exhaust valve cavity in fluid communication with the second expansion chamber and the exhaust port. A flow control system may be supported by the housing assembly and be couplable to a source of pressurized control fluid.

Abstract: A pump has a flexible liner which is expanded and contracted by application of positive and negative fluid pressure for receiving and discharging fluent material. The liner is received in a rigid shell which defines the maximum volume received. In discharging fluent material, a vacuum is applied to one side of the liner, while applying pressure to the other side so the liner is collapsed against the rigid shell. The liner is arranged so as to be the only part of the pump which contacts the fluent material, and is replaceable to effect rapid and easy cleaning of the pump. The liner has multiple pump cells which can expand and contract for moving fluent material through the pump cell. The pump cells can be sized and arranged so that by selection of particular pump cells which receive the fluent material, precise volumes can be metered by the pump.

Abstract: There is provided a pump system excellent in a maintenance ability and compatibility. The pump system comprises a pump (1) for transferring a liquid by alternately supplying air to air chambers (17a, 17b) to extend and contract a pair of bellows (13a, 13b) linked to a shaft (15). It also comprises a switching valve mechanism (2) for switching the air supplied to the pump (1). Switching mechanisms (40a, 40b) are employed to switch the pilot air for controlling the switching operation of the switching valve mechanism (2). The switching mechanisms are detachably attached to cases (16a, 16b) of the pump (1) from outside.

Abstract: A hydraulic drive system for providing a smoothed or near sinusoidal output flow characteristic for reciprocating piston pumps is disclosed. A solution to hydraulic hammer caused by rapid flow reversal in the hydraulic control valves used within the system is presented that is based about a sloped hydraulic spool piece used in hydraulic control valves.

Abstract: An energy exchanger device can be used for exchanging pressure energy from one fluid to another, or may act as a hydraulic compressor or fluid driven pump. A preferred device uses a jet nozzle to rotate a cylindrical rotor block having a number of axially oriented conduits within it. As the rotor turns, one end of each of the conduits is alternately connected, through a first set of ports, to either an inlet for a high pressure fluid, or an outlet for the high pressure fluid from which the energy has been extracted. Correspondingly, the other end of each of the conduits is alternately connected to either an inlet for a low pressure fluid or an outlet for the fluid to which the energy has been transferred. A freely sliding element, such as a ball, may be placed in each of the conduits to isolate the two fluids from each other.

Abstract: A pneumatically-actuated reciprocating fluid pump and shuttle valve combination operates in an “air-assist” mode and a “non-air-assist” mode. In the non-air-assist mode, the shuttle valve is shifted by a blast of pressurized supply air from the pneumatic chamber in its pumping stroke as the flexible diaphragms and drive shaft reach the end of their pumping stroke. This blast of pressurized air used to shift the shuttle valve has the effect of reducing the air pressure in the pneumatic chamber immediately prior to the point in time that the drive shaft reaches the end of its stroke in order to provide a cushioning effect at the end of each pumping strokes cycle, in order to lessen the effect of the drive shaft and diaphragms abruptly reversing direction at full air pressure. In the air-assist mode, a secondary source of compressed air is utilized to shift the shuttle valve, rather than drawing pressurized air from the pneumatic chamber during its pumping stroke.

Abstract: A pumping method and arrangement, in which at least two chamber pumps (A, B) are operated in order to achieve a constant output flow. In the pumping procedure and arrangement, the entry chamber (110, 130) of the chamber pump is pre-pressurised close to the actual working pressure after the filling stage in order to achieve a constant output flow.

Abstract: A method for reducing ice formation in a gas-driven motor and a reduced-icing, gas-driven motor are provided, the motor having a housing with a first pressure chamber and a second pressure chamber. At least one partition is disposed in the housing and is reciprocally moveable therein responsive to a motive gas being alternately provided to and exhausted from the first and second pressure chambers. A motive gas conduit is disposed between and connects the pressure chambers such that, upon providing the first pressure chamber with motive gas and exhausting the second pressure chamber of motive gas, a portion of the motive gas is permitted to pass from the first pressure chamber to the second pressure chamber through the motive gas conduit. Also provided are a reduced-icing diaphragm and piston pumps having the reduced-icing, gas-driven motor according to the present invention.

Abstract: A restarting device of a pump including a center rod defining fluid delivering chambers and driving chambers 11b and 12b. The restarting device of the pump further includes: a change-over valve 2 for switching a direction for the center rod to move, and a restarting hydraulic circuit 3 which, when a supply of the driving fluid from the change-over valve 2 to the driving chambers 11b and 12b in both sides is stopped, detects the supply of the driving fluid into the driving chambers 11b and 12b in both sides having been stopped and then causes the driving fluid to flow into the change-over valve, thereby restarting the supply of the driving fluid into the driving chambers 11b and 12b.

Abstract: There is provided a pump system excellent in a maintenance ability and compatibility. The pump system comprises a pump (1) for transferring a liquid by alternately supplying air to air chambers (17a, 17b) to extend and contract a pair of bellows (13a, 13b) linked to a shaft (15). It also comprises a switching valve mechanism (2) for switching the air supplied to the pump (1). Switching mechanisms (40a, 40b) are employed to switch the pilot air for controlling the switching operation of the switching valve mechanism (2). The switching mechanisms are detachably attached to cases (16a, 16b) of the pump (1) from outside.

Abstract: A method for reducing ice formation in a gas-driven motor and a reduced-icing, gas-driven motor are provided, the motor having a housing with a first pressure chamber and a second pressure chamber. At least one partition is disposed in the housing and is reciprocally moveable therein responsive to a motive gas being alternately provided to and exhausted from the first and second pressure chambers. A motive gas conduit is disposed between and connects the pressure chambers such that, upon providing the first pressure chamber with motive gas and exhausting the second pressure chamber of motive gas, a portion of the motive gas is permitted to pass from the first pressure chamber to the second pressure chamber through the motive gas conduit. Also provided are a reduced-icing diaphragm and piston pumps having the reduced-icing, gas-driven motor according to the present invention.

Abstract: The present invention relates to a micropump which is driven by movement of a liquid drop based upon continuous electrowetting actuation. The continuous electrowetting means a phenomenon that the liquid drop moves as the surface tension of the liquid drop is electrically varied in succession. When a tube in which electrolyte and a liquid metal drop are inserted is applied with voltage having periodically changing polarity via metal electrodes, the surface tension of the liquid metal is varied so that the liquid metal drop reciprocates in the tube generating pressure or force, which is used as a driving force of the micropump. The micropump is operated in a low voltage and consumes a small amount of electric power.

Abstract: Provided is a system for transferring and delivering a liquid chemical from a source to an end use station.

Abstract: A locking system for a moveable member supported by a support frame, the support frame having an engagement surface, the locking system comprising a lock member and an input device adapted to be mounted on the moveable member the input device being operably connected to the lock member. The input device is rotatable to move the lock member from a first position to a second position, the second position defining a locked position wherein the lock member is adapted to be in contact with the engagement surface. Means for allowing additional rotation of the input shaft after the lock member reaches the locked position is also provided.

Abstract: A grease/water pumping and separating system is provided with a pump mechanism that utilizes a motivating fluid to pump a grease/water mixture. The mixture is sucked into and discharged out of a pumping cavity. A movable biasing boundary, such as a piston, separates the motivating fluid from the grease/water mixture. The pump mechanism pumps the grease/water mixture to a separator unit which separates the grease and water components and directs the grease to a retaining tank and the gray water component of the grease/water mixture to an appropriate outlet.

Abstract: Three or more diaphragm pumps (12,14,16) are interconnected to sequentially receive an activation fluid from corresponding piston and cylinder pumps (18,20,22) synchronized by a control mechanism (24) which includes a distributor plate (42) with directive shallow slots (80,82,84) for conduiting activation fluid to a porting plate (44) and via openings (60,62,64) to the piston and cylinder pumps (18,20,22).

Abstract: A device for pumping a stock fluid by supplying and discharging a motivating fluid to a unit is described. The device develops the suction and discharge of the stock fluid through the motion of a movable biasing boundary within a cavity. The movable biasing boundary divides the cavity into a stock fluid cell and a motivating-fluid cell. In the case that the movable biasing boundary comprises a piston, a link joined to the piston may extend outside of the unit to as a means for driving the piston toward the motivating fluid cell. Each cell communicates with a fluid circuit that includes a source line, a valve or valves and a discharge line. The controlled supply and discharge of the motivating fluid to move the movable biasing boundary creates the discharge and suction of the stock fluid respectively. A valve directs the supply and discharge of the motivating fluid.

Abstract: The equipment for desalination of water by reverse osmosis comprises: a pump 1 for drawing the water to be salinated, a high pressure pump 25, a cylindrical block 8 housing two pistons 3, 4 connected to one another by a shaft 5 and disposed, freely slidable and liquid-tight, within respective cylinders 6, 7 being part of the same block (8) and separated from one another by a central plate 9, the latter being liquid-tight; the equipment further comprises an exchange valve 14 controlled by the position of said pistons 3, 4, as well as a cylinder or, in general, one or more containers, possibly arranged in series, in parallel or in series/parallel 15, containing one or more reverse osmosis membranes (16).

Abstract: Three or more diaphragm pumps (12,14,16) are interconnected to sequentially receive an activation fluid from corresponding piston and cylinder pumps (18,20,22) synchronized by a control mechanism (24) which includes a distributor plate (42) with directive shallow slots (80,82,84) for conduiting activation fluid to a porting plate (44) and via openings (60,62,64) to the piston and cylinder pumps (18,20,22).

Abstract: A device for pumping a stock fluid by supplying and discharging a motivating fluid to a unit is described. The device develops the suction and discharge of the stock fluid through the motion of a movable biasing boundary within a cavity. The movable biasing boundary divides the cavity into a stock fluid cell and a motivating-fluid cell. In the case that the movable biasing boundary comprises a piston, a link joined to the piston may extend outside of the unit as a means for driving the piston toward the motivating fluid cell. Each cell communicates with a fluid circuit that includes a source line, a valve or valves and a discharge line. The controlled supply and discharge of the motivating fluid to move the movable biasing boundary creates the discharge and suction of the stock fluid respectively. A valve directs the supply and discharge of the motivating fluid.

Abstract: A dual diaphragm pump includes a central housing having a pair of opposed housing surfaces, each surface having a housing diaphragm recess and a pair of housing valve recesses, and a pair of covers, each cover having a surface with a cover diaphragm recess and a pair of cover valve recesses. The covers are mated to the housing so that the diaphragm recesses form a pair of pumping chambers with diaphragms therein, and the valve recesses form valve chambers with check valves therein.

Abstract: An energy recovery device includes at least one cylinder, a piston slidable in the cylinder, a first valve for selectively connecting one end of the cylinder to waste liquid at a first relatively high pressure and to drain and a second valve for allowing feed liquid to enter the other end of the cylinder at a second lower pressure via a feed liquid entry port and to be discharged via a feed liquid discharge port from the other end of the cylinder in response to movement of the piston caused by waste liquid entering the one end of the cylinder. A rod which extends from the other end of the cylinder and into but not through the piston, ensures that the area of the piston acting on the feed liquid is less than the area of the piston acted upon by the waste liquid so that the piston acts as a pressure intensifier to discharge feed liquid through the feed liquid discharge port at a higher pressure than the pressure of waste liquid entering the one end of the cylinder.

Abstract: The present invention relates to a micropump which is driven by movement of a liquid drop based upon continuous electrowetting actuation. The continuous electrowetting means a phenomenon that the liquid drop moves as the surface tension of the liquid drop is electrically varied in succession. When a tube in which electrolyte and a liquid metal drop are inserted is applied with voltage having periodically changing polarity via metal electrodes, the surface tension of the liquid metal is varied so that the liquid metal drop reciprocates in the tube generating pressure or force, which is used as a driving force of the micropump. The micropump is operated in a low voltage and consumes a small amount of electric power.

Abstract: Two cylindrical pump cylinders are mounted end-to-end. A first piston is placed in the first cylinder, a second piston is placed in the second cylinder, and the pistons are interconnected. In one embodiment compressed air alternately drives the first piston in either direction, causing the interconnected second piston to draw and pump high viscosity liquid in the second cylinder through the use of check valves. In another embodiment compressed air is alternately injected into one side of the first piston and one side of the second piston, thus alternately drawing and pumping liquid on the other side of the pistons. A heating jacket is placed around the cylinder pumping the liquid to heat and thus lower the viscosity of the liquid. Piston movement sensors that sense the limits of piston movement within the cylinders are mounted in the cylinder wall.

Abstract: An object of the present invention is to provide a restarting device of a pump for restarting an operation of the pump automatically in such an event that the operation of the pump is shut down due to a change-over valve stopping in an intermediate position, which valve has been moved forth and back to switch a direction for a center rod of the pump to move.

Abstract: The invention relates to a system for the circulatory conveyance of media, with a drive and with two conveying chambers, the first conveying chamber constituting a feed chamber and the second conveying chamber a return chamber.

Abstract: A reversing valve for a compressed air membrane pump in which an equilibrium state of the main piston in the neutral position, leading to stoppage of the pump, is prevented by disposing the main system piston and the pilot system piston immediately adjacent to one another.

Abstract: A fluid powered diaphragm pump is provided which includes three means for supplementing the pilot valve signal to the main fluid valve spool. The means include a cross porting of the main fluid valve spool, or engineered orifices that communicate pressurized air being delivered to one of the inner diaphragm chambers of the pump to the main fluid valve spool by way of either the intermediate bracket or the pilot valve housing. Design features also include the location of the pilot valve assembly immediately below the pressurized fluid inlet cap and between the inlet cap and the main fluid valve assembly. Further, an integrated exhaust muffler is mounted directly to the main fluid valve housing and the main fluid valve housing includes a segmented sleeve assembly which makes it easier to service the main fluid valve assembly and, specifically, the main fluid valve spool.