Abstract: A pilot-operated valve has a main poppet controlling fluid flow between inlet and outlet ports in response to pressure in a control chamber. Fluid flow through a pilot passage, linking the control chamber and the outlet port, moves an exhaust spool between first and second positions to control fluid flow through passages in the main poppet. The first position blocks flow between the control chamber and the outlet port and provides a path between the control chamber and the inlet port. In the second position, flow between the control chamber and the outlet port is enabled, and a second path, that is more restricted than the first path, is provided between the control chamber and the inlet port. When the valve closes, flow through the first path allows movement of the main poppet at a faster rate than during opening when flow occurs through the more restricted second path.

Abstract: A valve includes a body; a liquid flow passage defined in the body and including a liquid inlet and a liquid outlet; a vent passage defined in the body and including an air inlet and an air outlet; a valve seat defined in the liquid flow passage; a liquid seal located adjacent the valve seat; a stem connected to the liquid seal and extending in the liquid flow passage away from the liquid seal through an aperture defined in the body. The stem includes a distal end located external to the body. The stem is movable to and from a first position where the liquid seal is mated with the valve seat and a second position where the liquid seal is unseated from the valve seat. An actuator is connected to the distal end of the stem. The actuator is selectively movable to move the stem from the first position to the second position. A check-valve is adapted to block flow of liquid from the air outlet to the air inlet in the vent passage, and to allow flow of air from the air inlet to the air outlet in said vent passage.

Abstract: A pilot operated valve has a main poppet that selectively controls flow of fluid between first and second ports in response to pressure in a control chamber on one side of the main poppet. The main poppet has an aperture extending between the control chamber and the first port. A pilot piston slides within the aperture and has the pilot passage with a pilot orifice and a first disk spring biases the pilot piston with respect to the main poppet. A pilot valve element selectively engages the pilot orifice to open and close the pilot passage and thereby controls motion of the main poppet. Forces from the first disk spring and a pressure differential between control and pilot chambers alter a position of the pilot valve seat with respect to the main poppet. The change in position compensates for effects on valve operation due to variation of the pressure at the two ports.

Abstract: The present disclosure provides a method, apparatus, and system of an inline direct acting solenoid pilot valve. The valve has a solenoid assembly with a longitudinally moveable core assembly that shifts alternatively between sealing engagement on a lower first end of the core assembly with a pilot port formed in a poppet and sealing engagement on an opposite upper end with a stationary pilot exhaust port in the solenoid assembly. The core assembly can move in the same or opposite direction than the poppet and thus is independently moveable from the poppet to effect the various modes of operation. Because the movement is independent, the core assembly can advantageously operate within the solenoid with a shorter stroke to produce a higher overall force per length relative to a conventional core assembly stroke that is longer than the poppet stroke. The overall design allows a more compact and simplified design.

Abstract: A diaphragm operated valve having the diaphragm attached at its lower end to a valve closure plug, and movable therewith, and attached at its upper end to a portion of valve body that forms the pressure cavity. The diaphragm has a stepped portion between its upper and lower ends which folds back on itself when the valve opens. The valve body has shoulder portions that support the diaphragm when the valve is closed to avoid stressing the diaphragm material due to pressure in the pressure chamber. This allows the outside diameter of the diaphragm to be minimized, and eliminates the need for fabric reinforcement. A filter screen is positioned flush with the surface of the valve plug so that high velocity flow across the screen while the valve is opening and closing removes accumulated dirt thereby making the screen self cleaning.

Abstract: A diaphragm operated valve having the diaphragm attached at its lower end to a valve closure plug, and movable therewith, and attached at its upper end to a portion of valve body that forms the pressure cavity. The diaphragm has a stepped portion between its upper and lower ends which folds back on itself when the valve opens. The valve body has shoulder portions that support the diaphragm when the valve is closed to avoid stressing the diaphragm material due to pressure in the pressure chamber. This allows the outside diameter of the diaphragm to be minimized, and eliminates the need for fabric reinforcement. A filter screen is positioned flush with the surface of the valve plug so that high velocity flow across the screen while the valve is opening and closing removes accumulated dirt thereby making the screen self cleaning.

Abstract: A device (RF) for regulating and/or stabilizing the flow of a fluid comprises a single body (20), envisaged for insertion in a pipe for passage of the fluid, in particular the inlet pipe of a solenoid valve (1). According to the invention, in the single body (20) of the device there is directly integrated an arrangement for silencing the flow of the fluid. The single body (20) is made in a single piece of moulded thermoplastic material.

Abstract: An electronic faucet (10) mounted on a countertop (12) includes a housing, at least one fluid inlet line (24a, 24b) extending into the housing, a fluid outlet (46) from the housing, a solenoid (142, 143) for operating a valve controlling the fluid flow between at least one inlet line and the outlet, and a control circuit (206) for controlling the opening and closing of the valve.

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 differential pressure valve simplified in construction includes a piston integrally formed with a main valve element and arranged on the upstream side of a main valve to define a chamber for introducing refrigerant from an inlet port. The piston has an orifice and a refrigerant passage for communicating with a chamber on a back surface side of the piston. The chamber is configured such that it can be connected, via a refrigerant passage and a pilot valve element, to a chamber on the downstream side of the main valve, which communicates with an outlet port.

Abstract: The device comprises: a solenoid valve of the bistable type controlled by means of an operating winding; a control circuit coupled for operation to a power supply source and capable of supplying to the operating winding of the solenoid valve a first and a second current pulse, for opening and closing the solenoid valve respectively; and a detecting and operating device associated with the said solenoid valve, capable of detecting a predetermined dangerous operating condition thereof, and of causing, in such a case, the automatic reclosing of the valve for cutting off the flow of the fluid.

Abstract: Method and apparatus for filtering contaminants from a pressurized fluid. First and second filter elements are arranged within a housing to receive a flow of pressurized fluid. Respective first and second portions of the flow are directed through the filter elements and impinge opposing sides of a piston member which is biased in a first position by a collapsible pressure responsive member, such as a buckling pin. So long as the differential pressure across the first filter element is below a selected threshold, the first portion of the flow passes through an outlet of the housing and the second portion of the flow is blocked. Once sufficient contaminants have been captured by the first filter element, however, the resulting increase in differential pressure causes a collapse of the pressure responsive member. This moves the piston to a second position and directs the second portion of the flow to the outlet.

Abstract: A speed governor for a pneumatic rotation motor having a pressure air inlet passage (15, 15?), an inlet valve (16; 56) including a flow controlling valve element (18; 58) located in the inlet passage (15, 15?), and a speed responsive activating device (24; 54) operatively connected to the inlet valve (16; 56), wherein the activating device (24, 54) comprises a pilot circuit with an activating surface (20; 70) on the valve element (18; 58), a restricted air supply opening (21, 72) communicating with the activating surface (20; 70), a bleed-off valve (24; 54) which communicates with the activating surface (20; 70) and which comprises an electromagnet actuator (27; 76), and a generator (30) driven by the motor and delivering to the actuator (27; 76) a voltage of a magnitude responsive to the actual motor speed to thereby make the bleed-off valve (24; 54) operate in response to the output voltage of the generator (30) and the actual motor speed.

Abstract: A relatively low pressure inert gas hazard suppression system (20) is provided which is designed to protect a room (22) or the like from the effects of fire or other hazard. The system (20) includes a plurality of pressurized inert gas cylinders (24) each equipped with a valve unit (26); each valve unit (26) is in turn coupled via a conduit (28) to a delivery manifold (30). The respective valve units (26) are operable to deliver gas from the cylinders (24) at a generally constant pressure (usually around 10-100 bar) throughout a substantial portion of the time of gas delivery, to thereby provide effective hazard suppression without the need for expensive high-pressure gas handling and distribution hardware and a reduction in room venting area due to lower room over-pressurization. Each valve unit (26) has a valve body (48) and a shiftable piston-type sealing member (56).

Abstract: A valve includes a housing having a fluid inlet and a fluid outlet and defining a fluid flow path between the inlet and the outlet. A check valve positioned in the housing has a valve seat in the flow path from the inlet, a valve member movable between a seated position against the valve seat blocking fluid flow from the inlet past the valve seat and an unseated position spaced away from the valve seat, and a spring for biasing the valve member toward the seated position. A main valve assembly is removably positioned at a home position in the housing in the flow path to control the fluid flow from the check valve to the outlet. The valve assembly has a portion which engages the valve member and maintains the valve member in it's unseated position so long as the main valve assembly is at the home position, the valve member being moved to the unseated position by the spring upon removal of the main valve assembly from the housing.

Abstract: A valve operable between a valve close position and a valve open position for a gaseous fuel system includes a housing having a fuel inlet port, a fuel outlet port and a chamber disposed between the fuel inlet port and the fuel outlet port A valve seat is disposed adjacent the fuel outlet port and includes an aperture. The valve further includes a magnetic coil and an armature magnetically coupled to the magnetic coil and disposed with in the housing. The armature is movable in response to the magnetic coil. A piston is coupled to the armature and is movable within the chamber away from the seat when the magnetic coil is actuated in the valve open position. Fuel flows from the inlet port through the chamber to the outlet port. The piston engages the seat when the magnetic coil is deactuated in the valve close position to prevent fuel from flowing from the inlet port to the outlet port. The piston includes a projection or radius for closing the valve seat aperture.

Abstract: The invention relates to an air blast device comprising an air flow control device disposed between an inlet conduit and an outlet conduit. The control device comprises an evacuation valve (16) that controls the flow of the air contained in a rear chamber to the outlet conduit (5). The air contained in the rear chamber serves to hold a main valve (2A) in its seat (2B). This blast device is characterized in that a seat (17) of an evacuation valve is located at the level of a front face (2C) of the main valve (2). In order to evacuate air contained in the rear chamber, evacuation valve moves toward the front in the direction opposite that of the main valve (2A) as it leaves its seat (2B).

Abstract: Disclosed is a composite valve comprising a valve body that is provided integrally with a solenoid valve portion and a differential pressure valve portion. The valve body is formed with an upper valve chest, a lower valve chest, a refrigerant introduction chamber that communicates with the upper valve chest and has a differential pressure valve seat, and a back pressure introduction chamber that communicates with the lower valve chest. A main valve element that is opened and closed by means of the solenoid valve portion is located between the upper valve chest and the lower valve chest. A differential pressure valve element that is opened and closed by means of a differential pressure between the refrigerant introduction chamber and the back pressure introduction chamber is located between these two chambers. The refrigerant introduction chamber, back pressure introduction chamber, and differential pressure valve element are arranged so as not be situated on the outer surface of the valve body.

Abstract: An improved solenoid valve assembly for controlling fluid flow having a valve body with an inlet and outlet, a diaphragm assembly with passages for providing fluid communication between the inlet and the outlet, and a movable seal pad responsive to an external signal for controlling flow through one of the passages. The improvement has the diaphragm assembly including a symmetrical fluid flow restrictor movable within the valve body, with a head portion, an intermediate portion and a guide portion surrounding a main body portion. The head portion has a fist end of the pilot passage which extends through the main body portion. The intermediate portion includes an annular extension with an upper side and a lower side. The guide portion has a plurality of legs extending from the main body portion for a distance substantially equal to the outer diameter of the annular extension, and is spaced from and interconnected with the intermediate portion by reduced diameter gullet portion.

Abstract: An electromagnetic valve has a cylindrical-shaped valve housing, a fixing core; a movable core; a first return spring; a coil; a first valve mechanism including a movable seat member, a second return spring, a first valve part, a first valve seat, and a first valve hole, and a second valve mechanism including a cylindrical-shaped valve seat member, a second valve seat, a second valve hole, and a second valve part, wherein, on the movable seat member, a cylindrical-shaped guide part, when the second valve part is seated on the second valve seat, is cut off from the valve chamber but, when the second valve part is separated from the second valve seat, forms an annular-shaped passage communicating with the valve chamber and is slidably fitted into the second valve hole; and a communication passage for allowing the annular-shaped passage to communicate with the interior of the guide part is formed.

Abstract: A valve arrangement that controls fluid flow of a working fluid in a fluid system. The valve arrangement including a valve body having first, second, and third pressure chambers functioning under pressure of an operating fluid. The operating fluid is independent of the working fluid. The valve arrangement further including a solenoid valve arranged with the valve body to operably provide fluid communication between the first pressure chamber and the second and third pressure chambers.

Abstract: A pilot operated valve has a main poppet that selectively controls bidirectional flow of fluid between two ports in response to pressure in a control chamber on one side of the main poppet. The main poppet has a pilot orifice that is opened and closed by a pilot poppet. A unique mechanism is provided to compensate for variation of a pressure differential on opposite sides of the pilot orifice. This mechanism has a pair of annular end members between which extends a spring formed by a plurality of helices. Multiple passages with check valves extend through the main poppet to communicate the greatest pressure among the two ports to the control chamber and the lowest pressure among the two ports to the side of the pilot orifice that is opposite the control chamber.

Abstract: A counter-flow prevention valve is disposed within a body of a pilot-type channel valve. While electrical power is applied to a solenoid coil and the pilot-type channel valve is opened, i.e., while a gas is flowing through the counter-flow prevention valve and the gas is expanding, heat generated by the application of electrical power to the solenoid coil is conducted via the body and is effectively transferred to the counter-flow prevention valve. Therefore, even if the gas contains water vapor and even if this gas is cooled due to significant expansion, the water vapor can be prevented from freezing within the counter-flow prevention valve. Moreover, the volume of the pipe between the pilot-type channel valve and the counter-flow prevention valve is small, thereby resulting in a fast rise in pressure within the pipe and a quick opening of the counter-flow prevention valve, which provides an excellent valve-opening response.

Abstract: The invention relates to a valve system (2, 3) comprising a housing (25), an actuator, a main valve (9.1, 9.2) disposed between an inlet chamber and an outlet chamber (18.1, 18.2), and a pilot chamber (26.1, 26.2). Said pilot chamber is linked with the outlet chamber (17.2) via a main valve (8.1, 8.2), comprising at least one pilot valve member (12.1, 12.2) and one valve body (12.1, 12.2) linked with the electromagnetic actuator (4.1, 4.2), and with the inlet chamber (17.1, 17.2) via at least one connecting channel (27.1, 27.2). The invention is characterized in that the stationary seat (11.1, 11.2) of the main valve (9.1, 9.2) is formed by an insert (31.1, 31.2) that is mounted in the housing of the valve system (2, 3). The main valve member (10.1, 10.2) is impinged upon on its diametrically opposed surfaces (32.1, 32.2, 33.1, 33.2) by the pressure present in the inlet chamber (17.1, 17.2) and the pressure present in the pilot chamber (26.1, 26.2). The pilot chamber (26.1, 26.

Abstract: The device comprises:

Abstract: A pilot operated valve has a main poppet that selectively controls bidirectional flow of fluid between two ports in response to pressure in a control chamber on one side of the main poppet. The main poppet has a pilot orifice that is opened and closed by a pilot poppet. A unique mechanism is provided to compensate for variation of a pressure differential on opposite sides of the pilot orifice. This mechanism has a pair of annular end members between which extends a spring formed by a plurality of helices. Multiple passages with check valves extend through the main poppet to communicate the greatest pressure among the two ports to the control chamber and the lowest pressure among the two ports to the side of the pilot orifice that is opposite the control chamber.

Abstract: A manual and automatic flow control valve includes a valve body, a manual control unit, a hollow pressure-releasing device, a middle plate, an upper casing, and an electric controlled magnetic unit. The internal of the valve body has a water inlet chamber and a water outlet chamber. A plastic main water flow valve is formed therebetween for isolating the two pressure chambers. A hollow pressure-releasing device is installed in a hollow portion of a main water flow valve. An upper side of the main water flow valve is a middle plate which is installed with an upper pressure chamber. The manual control unit can push the hollow pressure-releasing device to tilt. The electric controlled magnetic unit can control the hollow pressure-releasing device to communicate with the upper pressure chamber. If water drains from the lower pressure chamber, the water will push away the main water flow valve.

Abstract: An extended range proportional valve which can control rates of mass flow over continuous low, intermediate and high ranges has a pilot member mounted on an armature of a solenoid which can be dithered onto and off of a pilot opening in a main valve member which seals a main valve opening to control mass flow rates over the low range by varying the duty cycle and/or frequency of a pulse width modulated current in the solenoid coil. Intermediate and high flow rates are achieved by dithering the pilot valve member with a duty cycle and/or frequency sufficient to raise the main valve member relatively short and relatively long respective distances from the main valve seat.

Abstract: An extended range proportional valve which can control rates of mass flow over continuous low, intermediate and high ranges has a pilot member mounted on an armature of a solenoid which can be dithered onto and off of a pilot opening in a main valve member which seals a main valve opening to control mass flow rates over the low range by varying the duty cycle and/or frequency of a pulse width modulated current in the solenoid coil. Intermediate and high flow rates are achieved by dithering the pilot valve member with a duty cycle and/or frequency sufficient to raise the main valve member relatively short and relatively long respective distances from the main valve seat.

Abstract: This dispensing apparatus includes a shut-off valve having a magnetically actuated valve element. The valve element is moved into an open position by magnetic attraction from a magnet mounted to a movable actuator. The actuator is adapted to be raised by a liftable handle connected to the actuator or by application of an upward force applied by a bottle container to the actuator. In both cases, the valve element is moved vertically by the application of a vertical force to the actuator.

Abstract: A two-stage, bi-directional valve is provided for controlling gas flow into and out of a storage volume. The solenoid is provided to actuate a first stage piston to seal communication with a pressure source. In doing so, the sources imparted by the solenoid overcome biasing forces applied by a resilient spring on the first stage piston. Simultaneously, actuation of the first stage piston opens the bleed passage to permit the depressurization of space behind the second stage valve. Upon sufficient depressurization, the second stage valve is unseated from the main orifice by fluid pressure forces, thereby creating the flow path for escape of the gaseous fluid through the main orifice.

Abstract: An improved foreign particle resistant valve assembly having a pressure responsive diaphragm main valve member activated by a pilot valve which controls flow through small orifice passages whereby pressure forces are created across the diaphragm main valve member to permit and prevent flow through the main flow section of the valve. Several arrangements illustrate various configured foreign particle-screening passages that protect the pilot valve orifice passages from blockage. The screening may be an integral part of the valve body or may be a removable member to facilitate cleaning or manufacture, and may be adapted to metallic or plastic valves. Other embodiments provide the means to enlarge a pilot pressure drop orifice passage which would then be less susceptible to foreign particle blockage and could also be combined with the screening passage means of the first embodiment.

Abstract: The present invention relates to an electromagnetic valve which includes a valve tappet that is axially movably arranged in a valve housing and fastened to a magnetic armature, and a valve piston axially movable in the valve housing, a diaphragm-type pressure fluid passage in the valve piston that is closed or opened by the valve tappet, another unthrottled pressure fluid passage arranged between the valve piston and the valve housing that is closed or opened by the valve piston, pressure fluid channels which open into the valve housing on either side of the valve piston, with both pressure fluid passages closed in the initial position of the electromagnetic valve.

Abstract: A discharge valve is provided to open an electrically controlled pilot valve in emergency situations such as during an electrical or hydraulic failure. The discharge valve has a poppet that operates in response to a pressurized control signal, which may be produced by a hand operated pump. When the poppet opens in response to the control signal, a path is established for fluid to flow from a control chamber of the pilot valve, thereby opening the latter valve.

Abstract: In a main valve having a solenoid pilot operated valve, a movable core and a hollow plunger are movably received in a sleeve extending from a pressure control chamber through an electromagnetic coil. The plunger is structurally separated from a main valve member. A shaft is slidably received in the plunger. One end of the shaft carries a pilot valve member. A spring engages at the plunger and the shaft such that the free end of the shaft projects a predetermined length beyond an end face of the plunger. As long as the coil is deenergized, the spring separates the pilot valve member from a pilot valve seat. As soon as the coil is energized, the plunger is attracted to the core, the shaft is displaced in relation to the plunger, and the pilot valve member projecting from the lower end of the plunger closes the pilot valve seat. Due to the developing pressure difference, the main valve is closed and kept in a closed state.

Abstract: An extended range proportional valve which can control rates of mass flow over continuous low, intermediate and high ranges has a pilot member mounted on an armature of a solenoid which can be dithered onto and off of a pilot opening in a main valve member which seals a main valve opening to control mass flow rates over the low range by varying the duty cycle and/or frequency of a pulse width modulated current in the solenoid coil. Intermediate and high flow rates are achieved by dithering the pilot valve member with a duty cycle and/or frequency sufficient to raise the main valve member relatively short and relatively long respective distances from the main valve seat.

Abstract: A toilet room flush valve includes a body having an inlet and an outlet. There is a valve seat between the inlet and outlet and a valve assembly is movable within the body and positioned to close upon the seat to control flow from the inlet to the outlet. A cover is mounted upon the body and defines a pressure chamber with the valve assembly. There is a bypass connecting the inlet and pressure chamber whereby the pressure therein maintains the valve assembly upon the seat. A flex tube is fixed relative to the cover at one end thereof, with the other end of the flex tube being attached to the valve assembly remote from the pressure chamber. There is a passage in the flex tube opening to the body outlet at one end thereof. A vent passage connects the pressure chamber with the flex tube passage and a pilot controls flow through the vent passage.

Abstract: A valve for a dust collector comprises a bonnet and a valve body formed with a fluid port for introducing a pressure fluid filled in a pressure vessel; a diaphragm provided displaceably in accordance with an action of the pressure fluid introduced into a diaphragm chamber, for opening/closing a passage for making communication between the fluid port and a main dust collector body; and a disk member provided displaceably integrally with the diaphragm to shield the diaphragm so that it serves as a pressure-receiving surface for the pressure fluid when the pressure fluid is supplied to the main dust collector body.

Abstract: A pilot operated valve is provided to control a bidirectional flow of fluid between two ports. A main poppet selectively controls flow of fluid between the ports in response to pressure in a control chamber on one side of the main poppet. A pilot passage in the main poppet extends between the second port and the control chamber A first pair of check valves allow fluid to flow only into the pilot passage from the two ports. A second pair of check valves allow fluid to flow only into the control chamber from the two ports.

Abstract: A pressure relief system comprises a control system which includes a housing with a housing chamber in which electrical equipment is located, and a valve system having a pressure relief device. The housing chamber is connected via a connecting device (e.g., a pipe conduit) to the pressure relief device, thereby protecting the electrical equipment contained in the housing chamber from occurrence of overpressure.

Abstract: An extended range proportional valve which can control rates of mass flow over continuous low, intermediate and high ranges has a pilot member mounted on an armature of a solenoid which can be dithered onto and off of a pilot opening in a main valve member which seals a main valve opening to control mass flow rates over the low range by varying the duty cycle and/or frequency of a pulse width modulated current in the solenoid coil. Intermediate and high flow rates are achieved by dithering the pilot valve member with a duty cycle and/or frequency sufficient to raise the main valve member relatively short and relatively long respective distances from the main valve seat.

Abstract: An improved valve assembly having a valve member encased within a valve housing including a bonnet which is removably mounted on a lower or main valve body by one or more clamp members adapted for quick and easy disassembly without tools to facilitate access to the valve housing interior for service or maintenance. In a preferred form, the valve member is carried by a diaphragm for movement between closed and open positions in response to a solenoid actuator, for regulating the pressure within a control chamber acting upon the diaphragm. The clamp member or members are mounted on the housing bonnet for releasible clamp fit engagement with the main valve body. A bleed screw is mounted on the bonnet for selectively bleeding fluid such as air from the control chamber and normally engages and locks the clamp member or members in a position for retaining the bonnet and main valve body in assembled relation.

Abstract: A servo-controlled magnetic valve has a main valve (13) and a servo valve (14). The servo valve opens when, after an empty stroke, a solenoid plunger (7) entrains a slide member (23) that carries the servo closure member (20) and, as a result, pressure is released to the low pressure side (17) from a pressure chamber (25) on the side of the servo piston (24) that is remote from the main valve seat (15). The servo piston (24) is an annular piston that surrounds an insert (19) that carries the main valve closure member (18) and the servo valve seat (20) and which, during the operating stroke, entrains the slide member (23) by means of first stops (26) and the insert (19) by means of second stops (28). In that manner, it is possible to obtain sufficient opening of the main valve (13) and a small overall height of the magnetic valve while retaining an initial empty stroke of the solenoid plunger (7).

Abstract: A pilot operated valve assembly having a pressure responsive valve member for opening and closing a main valve, the pilot valve actuator permits a very small operating force and a short actuation travel which is less than the stroke of the main valve member. Compactness and manufacturing economy is attained by the incorporation of an insert structure within a valve housing to facilitate the arrangement of pilot valve and bleed passages that operate the pressure responsive main valve member. Valve construction permits an axial in line arrangement of pilot valve actuator and main valve member to further achieve a compact valve size and to ease manufacturing assembly.

Abstract: A pilot actuated spool valve assembly includes a valve body that defines a first passage, a second passage and a flow passage. A unitary pilot body is at least partially positioned in the valve body and has a first valve seat and a second valve seat. A pilot member is moveable in the pilot body between an up position in which the pilot member closes the first valve seat and a down position in which the pilot member closes the second valve seat. A spool valve member has a control hydraulic surface and is positioned in the valve body. It is moveable between a first position in which the first passage is open to the flow passage, and a second position in which the second passage is open to the flow passage. At least one of the valve body, the pilot body, the pilot member and the spool valve member define a control volume fluidly connected to the first passage when the pilot member is in one of its up position and its down position.

Abstract: A shaft and a piston are coupled to each other at an intermediate position of the shaft by a male screw formed on an outer periphery on a central portion of the shaft and a female screw formed on an inner periphery of a central hole of the piston, a sealant is provided between the shaft and the piston, a stopper ring is attached to the outer periphery of the shaft so as to prevent the piston from loosening, and a tip end portion and a proximal end portion extending to both sides of the pistons, respectively, of the shaft are slidably supported by respective bearings.

Abstract: In an own-medium controlled magnetic valve (2) actuatable by an electromagnetically controlled pilot vale (46) for controlling liquids, having a main valve member (50) in the form of a differential piston and means to suppress pressure surges during the closure of the main valve (12) implying the cooperation of an overflow channel (68, 80, 82) with a limited passage cross section between both sides of the main valve member (50). The overflow channel consists at least partly of an elastic-walled choke channel (80) which can be increasingly narrowed by squeezing during the closure of the main valve (12). This ensures that the closing movement takes place rapidly and with enduring precision despite gentle closing.

Abstract: A thruster valve has a continuously positionable piston between a closed position and a maximum open position. The piston moves in response to the difference in pressure between the pressure in the intermediate annulus and the pressure behind the piston. A pivotable flapper valve regulates this pressure difference. When a change in thrust is required, the position of the flapper is changed causing a change in this pressure difference which causes the piston to move until the desired thrust level is obtained.