Abstract: A valve assembly having a pressure dead band includes a first valve or sleeve slidably disposed within a valve body. A second valve is partially slidably disposed within the first valve and partially slidably disposed in the valve body. A plurality of fluid passages communicate with the valve assembly and provide a first flow of hydraulic fluid and a second flow of hydraulic fluid. A lower threshold of the pressure dead band is defined by the pressure on the combination of the first area of the first valve and the first area of the second valve required to balance the resultant force developed on the second area of the second valve. An upper threshold of the pressure dead band is defined by the pressure on the first area of the second valve required to balance the resultant force developed on the second area of the second valve.

Abstract: A thermal deburring apparatus has a pressure-tight closeable deburring chamber connected to an environment via a ventilation passage having a passage direction; a ventilation valve closing said ventilation passage and having a stationary valve seat encompassing said ventilation passage, a valve tappet that is movable in said passage direction, and a seal affixed to said valve tappet.

Abstract: Dome-loaded pressure regulators are disclosed. An example pressure regulator includes body having a pressure inlet and a pressure outlet. A piston is disposed in the body and fluidly coupled to the pressure inlet, the pressure outlet, and the pressure control inlet. The piston is configured to contact a valve seat and to control the flow of fluid from the pressure inlet to the pressure outlet in response to a pressure applied to a surface of the piston via the pressure control inlet.

Abstract: A device used for pneumatic control, includes a control piston carried in a cylinder. The control piston is mounted so as to be movable in the direction of a longitudinal piston axis, and a primary flow path that can be closed by the control pressure passes through the cylinder. The control piston is provided with a control surface that faces a control chamber of the cylinder and that is designed to transmit a control force to the control piston. The control piston is made at least partially of a plastic.

Abstract: A fluid control system, including: a housing having an inlet, an outlet, and a pressure chamber; a shuttle assembly adapted to reciprocate in the pressure chamber to regulate the flow of an operating fluid from the inlet to the outlet; the operating fluid applying an opening force to a first end of the shuttle assembly; a control fluid to apply a closing force to an opposite end of the shuttle assembly; wherein an operating fluid pressure area of the first end of the shuttle assembly when in a closed position is at least 65 percent of the operating fluid pressure area of the first end of the shuttle assembly when in an open position.

Abstract: A pressure limiting valve having a spool with raised spool lands. The spool is slidably received in a spool bore having inflow and outflow grooves that form control edges. The valve has two control edges, and a hydraulic resistance is connected in series with one of the control edges. Increasing static pressure losses at the control edges during flow, so-called flow forces, can be offset by an increasing back pressure on the valve spool, which is produced by the hydraulic resistance.

Abstract: A media control valve includes a valve body having a media inlet and a media outlet with the valve body being adapted to be mounted on a flow device for providing communication between the media outlet and the flow device. A pressure balance flow line is provided in communication with the valve body and also with the flow device at a point upstream of the media outlet for balancing the pressure in the valve. A check valve may be included in the balance flow line for assuring that flow generally flows from the flow device to the valve body. A cleanout port may be provided for permitting clean out of the valve without disassembly when not in use.

Abstract: A hydraulic control valve for heavy equipment is provided, which includes a valve body having a supply passage supplied with a hydraulic fluid from a hydraulic pump, ports for supplying the hydraulic fluid to an actuator or receiving the hydraulic fluid from the actuator, tank passages for returning the hydraulic fluid from the actuator to a hydraulic tank, and a first regeneration passage for supplying a part of the returned hydraulic fluid to the supply passage; a spool slidably installed in the valve body in accordance with supply of a pilot signal pressure from an exterior, and controlling flow of the hydraulic fluid supplied to the actuator from the supply passage during shifting; and a regeneration valve installed between the first regeneration passage and the tank passage, and including a piston moved by the hydraulic fluid from the hydraulic pump, a regeneration spool shifted by pressure fluctuation of the supply passage to variably adjust a flow rate of the hydraulic fluid discharged from the first r

Abstract: An overfill protection device includes a piston (5) comprising a main seal or semi-sphere packing (3) on its tip and a V-shaped packing (4) on its side, a retracting spring (2) for pushing the piston back to its original position, a main valve (7) with an o-ring that drops into the inner hole of the retainer (10) to block off the gas flow, a level arm consisting of a rising faced section (28) and a U-shaped section (29), whereby no gas will be allowed to flow through the overfill protection device when the gas reaches the predetermined 80 percent level.

Abstract: A pilot-type two-port valve is disclosed having a water hammer preventing mechanism, operative to prevent a water hammer during valve-closing operation, which includes a valve member operative to open or close a valve and a piston driven by pilot fluid for operating the valve member for opening and closing movements. The water hammer preventing mechanism comprises a piston drive chamber, from which fluid is discharged during valve-closing operation, which has an orifice for restricting the flow rate of discharge fluid whereby when the piston moves to a position to allow the valve member to be close to a valve seat, a portion of an discharge flow passage of the piston drive chamber is blocked to restrict the flow rate of the discharge fluid to the flow rate of fluid flowing through the orifice.

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

Abstract: A vacuum regulating valve has a poppet type valve element supported so as to be brought into uniformly close contact with a valve seat disposed in a passage connecting two main ports. The valve element is connected to a valve stem by a connecting mechanism that allows the valve element to tilt relative to the valve stem. A piston included in a cylinder actuator moves the valve stem axially.

Abstract: A replaceable sleeve insert for a choke assembly is disclosed, wherein the replaceable sleeve insert has a tubular member coaxially and sealingly retained within an upper body section of the choke assembly. The tubular member is also sealed against the bonnet. The tubular member has an inner diameter sufficient to accommodate coaxial linear displacement of a shuttle assembly and an outer diameter sufficient to fit within an upper body orifice in the upper body section. At least one attachment member outwardly extends from the tubular member and is retained between the upper body section and the bonnet. The tubular member has an opening in the sleeve wall to provide fluid communication from the choke inlet to the interior of the tubular member. A method of assembling a choke with a replaceable sleeve insert is also described.

Abstract: An oil pressure relief valve for use in the lubrication system of an internal combustion engine is controlled by both pump outlet pressure 3 and pilot pressure 2. The action of the valve reduces the start-up pressure spikes associated with known pilot-operated valves, while also permitting a fuel economy benefit.

Abstract: To provide a low-cost air-operated valve, an air-operated valve comprises a piston, a cylinder in which the piston is allowed to slide by operation air, and a valve section to be driven by sliding movement of the piston. The cylinder includes an outer member having a hollow portion and an inner member loaded in the hollow portion of the outer member to define a piston chamber in which the piston is allowed to slide.

Abstract: A closure device for closing an opening in a wall in a vacuum-tight manner comprises a closure plate, a carrying unit which carries the closure plate and which has at least one longitudinal piston-cylinder unit, and a base unit which carries the carrying unit and has at least one transverse piston-cylinder unit. A closing cylinder space of the at least one longitudinal piston-cylinder unit is connected to a closing cylinder space of the transverse piston-cylinder unit, or of at least one of the transverse piston-cylinder units, by means of a closing pressure gas channel, and an opening cylinder space of the at least one longitudinal piston-cylinder unit is connected to an opening cylinder space of the transverse piston-cylinder unit, or of at least one of the transverse piston-cylinder units, by means of an opening pressure gas channel.

Abstract: The present invention provides a failure protection apparatus including an air source providing air having an air pressure, a first valve in fluid communication with the air source permitting fluid communication of a control fluid between a first fluid port and a second fluid port when the air pressure is at least a minimum air pressure and preventing fluid communication of the control fluid between the first fluid port and the second fluid port when the air pressure is below the minimum air pressure, a second valve in fluid communication with the air source preventing communication of air between an air inlet and an air outlet when the air pressure is at least the minimum air pressure and permitting communication of air between the air inlet and the air outlet when the air pressure is below the minimum air pressure, a third valve in fluid communication with the air source permitting communication of air to a third valve outlet when the air pressure is at least the minimum air pressure and preventing communic

Abstract: Aseptic sampling valve having a valve body with a generally cylindrical side wall and a relatively thin, generally planar end wall, an inlet opening in the end wall, a valve seat surrounding the inlet opening, a port opening through the side wall and extending toward the inlet opening at an acute angle relative to the axis of the valve body, and a valve member movable axially within the valve body between open and closed positions relative to the valve seat for controlling communication between the inlet opening and the port.

Abstract: Accordingly, the invention provides a spray valve comprising: (a) an upper valve body including a hydraulic chamber for receiving an incompressible hydraulic fluid through a piston port and a piston slidable within said hydraulic chamber; (b) a lower valve body including a fluid conduit for receiving fluid into the spray valve, a lower valve seating surface, an annular fluid chamber around the lower valve seating surface and a fluid outlet; and (c) a seating member between the upper valve body and lower valve body including: (i) an upper seat for the piston within the hydraulic chamber of the upper valve body; (ii) a diaphragm of resilient material extending between the upper valve body and lower valve body; and (iii) a valve seat for bearing against the lower valve seating surface and closing the fluid conduit when pressurised incompressible hydraulic fluid is received through the piston port and displacing the piston within the hydraulic chamber.

Abstract: Booster means 11 for transmitting a force acting on a piston 10 to a valve stem 9 on amplification comprises pivotal members 25 each supported by casings 7, 8 so as to hold an outer end and an inner end thereof in contact with an outer peripheral portion of the piston 10 and a flange portion 22a formed on the valve stem 9 respectively from below and to be pivotally movable about a horizontal rod 26 positioned closer to the inner end. Metal bellows 16 are provided between an outer peripheral portion of the casing top wall 8a and the outer peripheral portion of the piston 10 for sealing off a compressed air admitting space.

Abstract: The present invention relates to a valve unit for container filling machines, particularly for bottle fillers. More particularly, the present invention relates to a valve unit (1), particularly for machines for filling containers (8), comprising a hollow body (2) in which a plug (3) is slidably housed and a guide means (14) for the said plug (3), a passage (9) being formed in the said hollow (2) for a fluid (7) for filling the said container (8), characterized in that the said passage (9) for the said filling fluid (7) is separated from the said guide means (14) and from the said plug (3) by an isolating and sealing membrane (32), the said membrane being open at the bottom in such a way as to allow a tip (30) of the to protrude downwards.

Abstract: The microvalve comprises a mini-piston moving due to the thrust of gases given off by firing of a pyrotechnic charge and comprising an aperture designed to enable communication to be established between ends of microchannels of a microfluidic component. When the ends between which communication is to be established open out onto a face of a first planar substrate, the mini-piston is formed in a second planar substrate, adjoined to the first, and comprises a part that is mobile in translation or in rotation in the plane of the second substrate. If a transverse slot is arranged between the ends of the microchannels between which communication is to be established, the mini-piston comprises a rod designed to slide in the slot and the aperture is formed by a transverse orifice formed in the rod of the mini-piston.

Abstract: A torque-transmitting mechanism control valve disposed between a hydrostatic source of pressure and a torque-transmitting mechanism is effective to direct fluid pressure to engage the torque-transmitting mechanism when a control pressure is present, effective to retain the valve closed when source pressure is present but control pressure is not, and to retain the valve closed when torque-transmitting apply pressure is present and source pressure is not and control pressure is not present.

Abstract: Methods and systems for retaining hydraulic fluid in a hydraulic valve actuation system adapted to be installed on an internal combustion engine are disclosed. The system may include a hydraulic fluid supply connected by one or more passages to a fluid accumulator and a hydraulic valve actuator. The one or more passages may include a retaining portion elevated above portions of the fluid accumulator and/or the hydraulic valve actuator. The retaining portion may include an air vent and thus prevent back flow of all the fluid in the accumulator and/or hydraulic valve actuator to the fluid supply during periods that the engine is shut off. Retention of hydraulic fluid in the system may be further enhanced during engine shut off by selectively controlling the release of hydraulic fluid from the hydraulic valve actuator during the engine shut off process.

Abstract: A coating material dispensing device includes a first component providing a connection to a source of coating material to be dispensed and a filter for filtering coating material to be dispensed. The first component includes a housing for housing the filter and a closure for selectively closing the housing to permit removal and replacement of the filter. The coating material dispensing device further includes a second component providing a nozzle through which the coating material is dispensed. The first and second components include first and second passageways, respectively. The first and second passageways communicate when the first and second components are assembled together to provide a flow of filtered coating material from the filter to the nozzle.

Abstract: A valve for controlling a flow of abrasive particles suspended in a pressurized carrier fluid has at least two apertured valve seats (74, 75) in face to face contact. One of the valve seats (74, 75) may be slid between a first position in which the apertures of each valve seat (74, 75) are aligned to allow fluid flow and a second position in which the aperture is one valve seat (74, 75) is blocked by the face of another (75, 74) to stop flow through the valve. The valve seats (74, 75) each have an outer layer of material with a hardness on the Mohs scale of at least 9, such as diamond. The valve is suitable for use in a fluid jet machining apparatus, particularly apparatus charged with a suspension of abrasive particles such as garnet in water.

Abstract: Low power integrated pumping and valving arrays which provide a revolutionary approach for performing pumping and valving approach for performing pumping and valving operations in microfabricated fluidic systems for applications such as medical diagnostic microchips. Traditional methods rely on external, large pressure sources that defeat the advantages of miniaturization. Previously demonstrated microfabrication devices are power and voltage intensive, only function at sufficient pressure to be broadly applicable. This approach integrates a lower power, high-pressure source with a polymer, ceramic, or metal plug enclosed within a microchannel, analogous to a microsyringe. When the pressure source is activated, the polymer plug slides within the microchannel, pumping the fluid on the opposite side of the plug without allowing fluid to leak around the plug. The plugs also can serve as microvalves.

Abstract: A quick closing shut-off valve includes an inlet, an outlet and a passage there between. A closing element blocks the passage when in the closed position. The closing element is interconnected to a piston via a pull rod. The piston is positioned within a working chamber that communicates with the valve outlet. A safety valve also communicates with the working chamber and is positioned above the piston. As a result, when the pressure within the tank, and thus in the working chamber, reaches a maximum permissible pressure, the safety valve opens and the pressure above the piston decreases. The piston rises as a result and pulls the closing element via the pull rod into the closed position so that the valve is closed.

Abstract: The present invention provides a filling valve which affords an excellent sterilization capability and a high maintenance capability. The valve includes a tubular nozzle 4, an operating rod 6 which is fitted in the nozzle 4 so as to be elevatable, and an opening/closing valve 22 formed by a valve seat 10a on the internal surface of the nozzle 4 at its bottom end and a valve element 6a formed at the bottom end of the operating rod 6. A portion 10c of a reducing diameter which gradually reduces the cross-sectional area of the filled liquid passage 10 in a downward direction and a portion 10e of an increasing diameter which gradually increases the cross-sectional area of the filled liquid passage 10 in the downward direction are formed on the internal surface of the nozzle 4 at an upper portion thereof. A plurality of straightening vanes 36 are formed on the internal surface of the nozzle 4 at a location below the portion 10e of an increasing diameter.

Abstract: A pneumatically actuated fluid control valve includes a piston and a piston actuator including a permanent magnet. First and second piston actuator positions for magnetically disposing the piston in valve open and valve closed positions are provided. A pneumatic actuator driving circuit pneumatically moves the piston actuator from one to the other of first and second piston actuator positions to dispose the piston in the open and closed positions. The valve includes an annular valve assembly. One valve assembly position is a normally closed position and a positive air flow control signal moves the piston to open the valve. Another valve assembly position is a normally open position and a positive air flow control signal moves the piston to close the valve.

Abstract: A thruster gas control mechanism for controlling a flow of thrust gas through a gas nozzle, the mechanism having a plunger movable into and out of the gas nozzle, the plunger being connected to two movable baffles. The two baffles form two channels with two side walls of the mechanism. A movable armature controls flow of other thruster gas through either of the two channels, or through both channels, to cause the baffles and plunger to move toward or away from the gas nozzle, and causing the plunger to move into or out of the gas nozzle.

Abstract: A check valve arrangement for a hydraulic consumer which permits connecting the hydraulic consumer selectively to a medium pressure line or a high pressure line. The valve arrangement comprises a medium pressure switching valve 10, a high pressure switching valve 14, and a check valve 6 downstream of these valves. The check valve 6 is constructed as a combined sliding and seat valve and comprises control surfaces 28, 29, 38 for the medium pressure P1, the high pressure P2, and the pressure applied to a consumer line 5, i.e., the pressure applied to the hydraulic consumer. The control surfaces are dimensioned such that a connection of the hydraulic consumer to the high pressure line can occur only when a predetermined limit pressure is reached in the hydraulic consumer.

Abstract: This invention relates to an improved air operated fluid control valve which tends to inhibit or impede the travel of a fluid to the air controlled side of the control valve. The air operated fluid control valve includes a control valve having a valve body provided with at least one fluid inlet port and at least one fluid outlet port, at least one air inlet port and at least one air outlet port, and a piston assembly selectively controlled by the air inlet and outlet ports so as to regulate the flow of a fluid through the valve body from the at least one fluid inlet port to the at least one fluid outlet port. According to one preferred embodiment of this invention, the control valve includes at least one shield member carried by piston assembly which is operative to inhibit the travel of a fluid from a fluid side of the control valve into an air controlled side of the control valve.

Abstract: A shutoff valve includes a positive position indicator for indicating the position of a piston in the valve. The valve position indicator is operably connected to a piston within the valve so that movement of the piston causes a corresponding movement of the valve position indicator. The shutoff valve may also include one or more springs acting on the piston to close the valve. Each spring is independently capable of closing the valve.

Abstract: A hydraulic damper cylinder 270 is provided for an electromagnetic actuated internal combustion engine cylinder valve 20. The damper includes a piston 68 slidably mounted within the damper cylinder 270. The piston 68 bifurcates the cylinder 270 into a first control volume 74 and a second control volume 76. The first and second control volumes are fluidly connected by an inboard flow path 372. Along the extreme ends of travel, the flow path 372 is blocked by the piston 68 and damping occurs through fluid transfer through an outboard flow path 374.

Abstract: A device and control method for actuating valves of a motor vehicle internal combustion engine including at least a controlled hydraulic actuator actuating the associated valve that is provided in the form of a cylinder. A mobile piston connected to the valve delimits two opposite hydraulic pressure chambers each supplied with an incompressible fluid and pressure regulated by a control unit such that the pressure prevailing in one of the chambers is alternately higher/lower than that which prevails in the other chamber to actuate the valve. Each pressure chamber of the cylinder is capable of communicating with a corresponding actuating hydraulic pressure source, which includes a pneumatic return mechanism for the fluid.

Abstract: An inlet throttle valve for supplying liquid to a high-pressure pump has a fully open start position and an operating range where flow through the valve is determined by a pressure balance of a valving member independent of the pressure of oil supplied to the inlet throttle valve. The valve includes a hydraulic stop limiting closing movement of the valving member. The valve may be used to flow low-pressure oil to a high-pressure pump for supplying high-pressure oil to HEUI injectors or other components of an internal combustion engine.

Abstract: A flow controller (1), comprising a valve body (4) having flow paths forming an inlet and an outlet of fluid, a diaphragm (6) held fixedly between the valve body and a bonnet (5), and an operating mechanism (7) moving the diaphragm vertically, wherein the valve body flow paths communicate with each other through a projection-free communication path (8), the a diaphragm is formed so that, when lowering, it comes into close contact with the communication path so that it closes the flow path and, when rising, the center part thereof is recessed so that an area near the outer peripheral part is raised, and a curved surface (52), to which the outer upper surface (63) of the raised part is closely fitted, is formed on a bonnet on the inner lower surface of a diaphragm holding part (51).

Abstract: A pressure-responsive type pressure holding valve is proposed which serves to hold the hydraulic pressure in a circuit connected to a spool valve. A piston valve biased by a spring is mounted in a housing formed with a valve chamber, a small-diameter bore and a large-diameter bore. The outer periphery of the small-diameter portion of the piston valve is sealed by a seal member. A first port opened and closed by a valve head at the tip of the piston valve is connected to a circuit that needs pressure holding, a second port to a circuit in which minute leak can occur, and a third port to a source of hydraulic pressure for opening the valve.

Abstract: A pressurized-fluid-operated actuator has multiple piston surfaces for providing increased output force. The actuator includes a stationary cylinder that contains a movable cylinder having multiple inner chambers separated by stationary inner pistons. The inner chambers are in fluid communication with extension and retraction ports provided in the stationary cylinder wall. Introduction of pressurized fluid into one port causes the fluid pressure to act on “n” piston surface(s) to retract the movable cylinder. Introduction of pressurized fluid into the other port causes the fluid pressure to act on “n+1” piston surfaces to provide an increased output force without increasing the diameters of the cylinders and without increasing the pressure of the fluid.

Abstract: In a compressor at least one bypass valve is arranged in a low-pressure zone inside a casing of the compressor. The bypass valve defines a chamber connected by a first duct to at least one compression pocket situated in the peripheral zone of the compression stage and by a second duct to the low-pressure zone, the two ducts opening near one another so that they can be shut off by a shutter which can move in the chamber, being guided by the walls that delimit this chamber, a third duct intended for conveying a shutter-control fluid opening into the lower wall of the chamber of the valve. The shutter is opened by gravity when no control fluid is applied.

Abstract: An exhaust processor includes a soot filter and a filter regenerator. The filter regenerator is configured to burn off particulate matter collected in the soot filter to regenerate the soot filter.

Abstract: A valve for bringing gaseous fuel into the combustion chamber of gas engines is provided with a solenoid valve (8) controlling fuel delivery (7) and an adjoining poppet valve (2), which closes biased by the force of a spring, and which opens in the direction of the combustion chamber through the pressure of in-flowing gas. For the purpose of keeping the poppet valve (2) open, independent from the pressure conditions at its valve head (3), the valve's stem (4) is connected to a step piston (6) whose topside and bottom side are biased by the fuel pressure existing between the solenoid valve (8) and the valve head (3) and whose step area (12) is in communication with the fuel delivery line (7), on one side, and with the space (11) between the step piston (6) and the valve head (3), on the other side, whereby the passageways (15, 15′, 17, 17′) are opened and closed by means of a respective switching member (13, 14, 20) corresponding to the movement of the step piston (6).

Abstract: A subsea actuator and method is disclosed that includes all moving components mounted in a compact, concentric configuration. The subsea actuator is highly reliable and will operate at depth even with zero valve body cavity pressure. A preferably cup-shaped spring pusher is provided in telescoping relationship to the hydraulic chamber. A piston position indicator is provided which is connected externally to the hydraulic piston cylinder to avoid the possibility of hydraulic leaks due to the piston indicator. A manual override may be provided with a manual override indicator. The manual override indicator has a shorter travel length than the manual override operating stem to thereby reduce the overall length of the manual override assembly. The driving stem provides a removable connection to the hydraulic piston from the top of the actuator housing and a quick disconnect permits disconnection of the driving stem from the valve stem.

Abstract: A preventative stop valve system for a wheeled trailer carrying hydraulic equipment is disclosed comprising a stop valve fitted for insertion in-line into the hydraulic line servicing the trailer equipment; the stop valve comprising a reciprocating piston moveable between open and closed positions. The stop valve is connected to the pressurized air line extending to the air brakes of the trailer. Actuation of the stop valve is controlled pneumatically by the setting and release of the air brakes of the trailer by the operator, utilizing conventional controls for the air brakes. A manual override mechanism is further provided for opening the stop valve manually in the event that the hydraulic equipment carried by the trailer must be utilized when pressurized air line to the trailers is disconnected.

Abstract: An actuator assembly and method for making and using an actuator assembly. In one embodiment, the assembly includes an actuator body having an actuator channel with a first region and a second region. An actuator is disposed in the actuator channel and is movable when in a flowable state between a first position and a second position. A heater is positioned proximate to the actuator channel to heat the actuator from a solid state to a flowable state. A source of gas or other propellant is positioned proximate to the actuator channel to drive the actuator from the first position to the second position. The actuator has a higher surface tension when engaged with the second region of the channel than when engaged with the first region. Accordingly, the actuator can halt upon reaching the second region of the channel due to the increased surface tension between the actuator and the second region of the channel.

Abstract: The hydraulic system for actuation of the mud valve of a measurement-while-drilling tool is characterized by a hydraulic actuator having a piston operatively connected to the mud valve of a measurement-while-drilling tool, which hydraulic actuator incorporates an internal by-pass which, cooperatively with movement of the piston, opens to unload hydraulic pressure from the system at either end of stroke of the piston. Return from the by-pass to the pump may be restricted so as to maintain some hydraulic pressure on the piston at end of stroke so as to prevent movement therefrom by external forces. The hydraulic system may include a high pressure relief valve, hydraulic fluid strainer and a device to equalize pressure between hydraulic system pressure and pressure external of the system.

Abstract: The present invention relates to a variable capacity helical screw compressor for compressing a gaseous medium, usually air. The compressor includes at least one lift valve (1) which connects with a first compression chamber in the compressor.

Abstract: A high vacuum valve assembly comprising a valve body with an air chamber formed therein. A gate unit is disposed within the air chamber and includes a valve gate portion disposed to mate to a valve seat, the valve gate portion and the valve seat portion each being disposed at the same angle to provide increased sealing force. The gate unit is urged into closure against the valve seat by a first tension source, which may be a spring, and away from the valve seat by a second tension source, which may be compressed gas, such that the gate unit comprises the only moving part of the valve.

Abstract: A water well recharge throttle valve (1) is configured as a hydraulic actuated flow control device (5) that permits calibrated throttling of water used in Artificial Storage and Recovery (ASR), Salt Water Barrier, Dedicated Recharge and Injection Wells to prevent the free cascading of water and thereby eliminating the entrainment of air which may cause air fouling, bio-fouling, calcite formation with a resultant reduction in permeability of the aquifer.