Abstract: A bellows valve assembly installed in a fluid pathway includes a valve body, a bellows housing positioned adjacent the valve body, and a valve actuator. The valve body is equipped with an inlet, an outlet, a valve bore positioned between the inlet and the outlet, and a valve seat disposed between the inlet and the outlet. A valve closure element having a sealing surface is positioned in the valve bore and is engageable with the valve seat to restrict fluid flow through the valve bore. The valve closure element also has a valve stem that extends from the valve bore through the bellows housing. The valve stem has a lower portion characterized by a first average diameter and an upper portion characterized by a second average diameter that is at least 25% smaller than the first average diameter. The actuator is engageable with the upper portion of the valve stem to move the sealing surface relative to the valve seat.

Abstract: A sub-sea coupling comprises a male probe coupler and a female receiver coupler containing mutually engageable poppet valves which have intermediate valve heads between nose and shank portions which seal with respect to the respective couplers. Each valve has a longitudinal passageway allowing balancing of the poppet valve with respect to external pressure. Further, the poppet valves have substantial equality in effective area between the valve portions and the nose and shank portions so that the poppet valve is substantially balanced with respect to line pressure in the line to which the coupler is connected. The arrangement gives a high resistance to the ingress of sea water to the couplers while substantially avoiding any hydraulic lock or wash-out during make-up and separation of the couplers.

Abstract: A hydraulic control valve includes a valve housing defining a valve chamber having first and second axially spaced valve seats of identical diameters, a control cylinder and first and second end cylinders. The valve chamber, the control cylinder and the first and second end cylinders are axially arranged in a series and form a cavity. A first pressure conduit communicates with the control cylinder, a second pressure conduit communicates with the first end cylinder, a third pressure conduit communicates with the second end cylinder; a control conduit communicates with control cylinder; and a discharge conduit communicates with the valve chamber.

Abstract: There are disclosed three embodiments of a gate valve having a fail safe actuator which is especially useful in a subsea environment at considerably depth below water surface. The gate is urged to open position by control pressure and is moved to closed position, upon loss of a controlled condition, by means of a spring acting between the actuator and the stem. In one embodiment, when the body pressure is low, a floating ring sealably shiftable within an annular space between the stem and actuator is urged by body pressure into a position to engage a stop on the stem, and thus provide a force urging it in a direction to close the gate, when body pressure is below ambient, and by ambient pressure to a position to engage a stop on the actuator when body pressure is above ambient.

Abstract: An expansion valve having a valve element, which valve element co-operates with a valve seat arranged between a first port and a second port in a housing, and is movable by an operating device in one direction and by a restoring device in the opposite direction along the same axis relative to the valve seat. It is desirable to make the properties independent of the operating direction in which the refrigerant flows. For that purpose, the valve element is connected to a first pressure surface arrangement, which comprises first pressure surfaces of substantially equal size acting in opposite directions, on which the pressure in the first port acts when the valve is closed, and to a second pressure surface arrangement, which comprises second pressure surfaces of substantially equal size acting in opposite directions, on which the pressure in the second port acts when the valve is closed.

Abstract: A positive-displacement pump includes multiple pumping elements, each pumping element having a pressure vessel with a first and a second chamber and a separating member disposed between the first and second chambers. The first chambers and the second chambers are hydraulically connected to receive and discharge fluid, wherein the separating members move within the pressure vessels in response to pressure differential between the first and second chambers. A valve assembly having suction and discharge valves communicates with the first chambers. The suction and discharge valves are operable to permit fluid to alternately flow into and out of the first chambers. A hydraulic drive alternately supplies hydraulic fluid to and withdraws hydraulic fluid from the second chambers such that the fluid discharged from the first chambers is free of pulsation.

Abstract: A balanced valve for flows operated by the axial driving of a stem which commands a sealing body liable to axially slip between an opened position far from the valve seat and a closed seal in contact with the valve s eat. The valve basically consists in a valve body having an inlet opening for the flow with a valve seat at the bottom. The valve body also has an opening for the flow outlet oriented in a substantially cross-section way to the flow inlet. Between the inlet and outlet of flow there is a cylindrical cavity with a ring-shaped broadening in the zone communicating with the flow outlet above the valve seat. There is an elastomeric sealing body located inside the cylindrical cavity, which is mainly made up of a relatively solid sealing end, with a slightly greater height than the height of the ring-shaped broadening of the cylindrical activity.

Abstract: The fluid pressure device includes a valve housing 2 in which a spool hole 14 is formed, and a spool 18 having a first spool portion 22 inserted in the spool hole 14, and the spool portion 22 is movable with respect to the first hole portion 26 of the spool hole 14 in its axial direction. More fluid grooves 110 are formed in the first spool portion 22. Pressurized fluid acting on one side of the fluid groove 110 have pressure higher than that of pressurized fluid acting on the other sides of the fluid groove 110. A first gap between an outer peripheral surface of the one side of the seal portion and an inner peripheral surface of the first hole 26 between the adjacent fluid groove 110 is set slightly greater than a second gap between an outer peripheral surface of the other side of the seal portion and the inner peripheral surface of the first hole.

Abstract: An electromagnetically operable valve has a valve seat and a valve body. A valve stem forms a guide part provided with a shoulder, by way of which guide part the valve is axially movably guided in a valve guide. A valve disk which, in the closing position of the valve, while forming a hydraulically effective seat diameter, rests against the valve seat. An electromagnetic adjusting device and a spring guide the valve into respective end positions. A control space with a fuel pressure bore is formed between a shoulder of the guide part and the valve disk, and hydraulic forces in the control space act upon the shoulder and the valve disk.

Abstract: A control valve comprising a valve housing including a valve cavity, an inlet means formed in the valve housing for directing fluid into the valve cavity, and an outlet means formed in the valve housing for directing fluid out of the valve cavity. The control valve further includes a valve element mounted for reciprocal movement in the valve cavity between open and closed positions and biased toward the closed position by fluid pressure forces. A valve seat is associated with the valve element which engages the valve seat when in the closed position and permits flow between the valve seat and the valve element when in the open position. A flow force inducing means is positioned adjacent the valve element for redirecting fluid from the inlet means through a predetermined flow path arranged relative to the valve element to cause fluid flow to impact the valve element and create flow induced forces of sufficient magnitude necessary to advantageously counteract the fluid pressure forces.

Abstract: In-line control valve constructions are described which include a piston-type valve assembly and a plurality of control chambers (C1,C2,C3,C4) controlled via one or more controls ports (CP1, CP2) to provide a normally-open valve may be closed by controlling the fluid pressure applied to the control port (CP1, CP2), or a normally-closed valve which may be opened by controlling the fluid pressure applied to the control port (CP1,CP2). Also described are valves which have a balanced construction and which therefore include relatively small actuators for opening and closing the valve.

Abstract: A valve filter is provided particularly for a balanced pressure valve and provides a means of preventing particles passing, through the balance holes of the valve plug.The valve comprises a valve housing and a valve plug movable in the housing to open and close the valve, the valve plug containing at least one balance hole, the balance hole defining a fluid communication channel through the valve plug, the fluid communication channel being provided with a filter, the filter comprising a body member and a plurality of elements, each element having a first end and a second end and being fixed at its first end to the body member and being, free at its second end, whereby the elements can deflect under pressure.

Abstract: A valve assembly (14) has an internal main flow passage through a valve body (24) between a first port (25) and a second port (26), an electric actuator (30), and a valve (86) operated by an armature (58) of the actuator to selectively open and close the passage. A force-balancing mechanism (92) applies to the valve (86) a force that opposes force created by pressure differential between the first and second ports. This mechanism includes an internal chamber (126) bounded in part by a fluid-impermeable movable wall (94) that extends between and is sealed to both the body (24) and the valve (86), and a communication passage (110, 112) that communicates one of the ports (26) to the chamber space when the valve is closing the passage. The valve (86) has a head part (88) and a seal part (90) joined together. The seal part seals the head part to the valve seat (29) when the valve is closing the passage. A retainer part (116) holds the inner margin of the movable wall sealed on the head part.

Abstract: The present invention relates to an arrangement in a valve actuator (101) operating on a valve stem (113) provided with a piston (114) so as to close or open the valve (111), and in order to arrive at a variable area type hydraulic piston/cylinder, it is according to the present invention suggested that in addition to the valve stem piston (114) there could be provided one or more supplemental pistons (124).

Abstract: The valve according to the invention in intended, in particular, for high-pressure gas containers containing up to 300 bar. It comprises a shut-off element which is hold on its valve seat under the action of a compression spring and of the gas pressure. In order that the high closing pressure can be overcome with relatively little force, a piston whose top surface has a larger diameter than the diameter of the valve seat is provided on the actuating side. This top surface is situated in a pressure space which can be connected to the interior of the gas container via a pressure-balance passage by means of an electromagnetically actuable closing element.

Abstract: A flow force compensating method for a flow control valve and a flow control valve using the same method, in which a spool is supported by hydrostatic bearings within a sleeve and fluid flow from the hydrostatic bearing flows into a valve space defined between a spool land and a circumferential groove of the sleeve, wherein a circumferential groove is formed in the spool land, bearing fluid flow flowing out of the bearing into the valve space defined between the circumferential groove and the sleeve groove is directed toward a central axis of the spool, and control flow is swirled by the bearing fluid flow, thereby compensating a flow force, acting on the spool.

Abstract: A steam control valve is provided with a valve core arranged in the valve housing (10), with an upper valve spindle (5) guided in a sealing packing (12), with a valve cone (1) sliding in a lower and upper valve core (3b) and (3a), and with a valve diffusor (6) arranged in the valve housing (10). Piston rings (4a) are inserted in the upper part (1a) of the valve cone (1) sliding in the valve core upper part (3a), and piston rings (4b) are inserted in the lower part (1c) of the valve cone (1) sliding in the valve core lower part (3b). Clean water is used as the hydraulic fluid for the hydraulic drive attached to a connection spacer (15). At least one axial hole (2) is provided in the valve cone (1). With the upper part (3a) and the lower part (3b) of the valve core (3), the middle part (1b) of the valve cone forms an annular chamber (8), at which at least one suction channel (9) is arranged.

Abstract: A valve assembly for use in an internal combustion engine is disclosed. The valve assembly includes a housing which defines a chamber. The housing further defines an outlet, a first inlet, and a second inlet, each of which is in fluid communication with the chamber. The valve assembly further includes a master valve positioned within the chamber. The master valve isolates the first inlet from the outlet when the master valve is positioned in a seated master position. The master valve places the first inlet in fluid communication with the outlet when the master valve is located in an open master position. The valve assembly still further includes a slave valve positioned within the chamber. The slave valve isolates the second inlet from the outlet when the slave valve is positioned in a seated slave position. The slave valve places the second inlet in fluid communication with the outlet when the slave valve is located in an open slave position.

Abstract: A flow control valve includes a valve member mounted in a valve chamber having an inlet port, through which a fluid flows into the valve chamber, and an outlet port through which the fluid flows out of the valve chamber. The valve member is slidable in the valve chamber in response to a driving force applied from an actuator. Valve seat member is mounted in the valve chamber in opposed relation to the valve member, the valve seat member cooperating with the valve member to control a rate of flow of the fluid. The valve seat member has at least a first hole formed therein and extending in a direction of driving of the valve member, a second hole formed therein and extending from an outer peripheral surface thereof and a third hole which is separated from the first hole and extends from its surface facing the valve member to the second hole in a direction of driving of the valve member, the second hole extending in a direction substantially perpendicular to the direction of driving of the valve member.

Abstract: A flow control valve having a pressure compensation function. This valve is free of fluid leakage and needs no pressure sensor.

Abstract: A valve seal system for passageway through a valve body emerging through a first generally flat and rigid surface, having a valve member including a resilient seal with generally flat exposed surface adapted to be brought into contact with the generally flat rigid surface, and having a generally circular, raised resilient ring portion extending from the generally flat exposed surface, the raised resilient ring portion adapted to be compressed against the generally flat rigid surface to seal the resilient seals against the generally flat rigid surface when said valve member is moved to a closed position by virtue of the raised resilient ring portion being compressed against the generally flat rigid surface.

Abstract: The blanketing valve has a diagnostic port to aid in analyzing the valve's operation. A pressure gauge is connectable or permanently connected to the diagnostic port. The diagnostic port measures the pressure above a main valve in a passageway connecting a pilot inlet chamber and a main valve piston chamber. This pressure controls the main valve and is an indicator of pilot valve action. Comparing this pressure to inlet pressure indicates pilot response and is a valuable aid in determining what problems may exist.

Abstract: An apparatus for preparing flowable reaction mixtures from at least two flowable reactants in which the components are injected into a mixing chamber by means of injection nozzles, the force of the reactant acting upon the nozzle needle is at least substantially compensated to avoid impairing the mixing ratio during a change-over of the nozzle needle. The rear end of the nozzle needle is provided with a chamber communicating with the component supply line.

Abstract: The invention particularly relates to a solenoid valve used in a control fluid, and one end of a center pole on the side opposite from a plunger is covered with theend face of a housing, and a communication passage is formed in the housing to communicate a through hole of the center pole with an opening formed on the housing on the side of the plunger. The communication passage has an end face groove and at least one side face groove on the end face and the side face of the housing. A volume of the side face groove is larger than a variation in volume of a space between the plunger and the center pole due to the movement of the plunger, and it is 2.5 times or more of the variation in volume of the space between the plunger and the center pole due to the movement of the plunger.

Abstract: An undersea hydraulic coupling includes a pair of interconnectable male and female members where each of the members includes a body portion and a fluid valve disposed within the body portion. The male and female members cooperate with the fluid valves to actuate the valves such that the valves are placed in either an open position or a closed position to control fluid flow therebetween. The female member has a receiving chamber for receiving the male member, and a longitudinal axis defining a direction of engagement and disengagement between the male and female members. The undersea connector includes at least one annular seal in the receiving chamber for engaging the male member in sealed cooperation with the female member when the male member is received within the receiving chamber.

Abstract: A valve to control fluid of high volume and pressure comprising a continuously balanced hollow plunger disposed within an annularly enlarged chamber that controls fluid flow by moving radial slots and ports in its peripheral wall back and forth across seals, the plunger being continuously balanced in any position by a double-rodded piston assembly comprising a piston, a ported operator rod and actuator rod, and a balance chamber within a sealed piston cylinder tube that allows the line media to flow through, out of, and around the plunger, through the operator rod and through and out of the actuator rod and into the balance chamber creating a complete continuous balancing effect on the plunger in any position, and operator means are only required to overcome seal friction and path resistance to move the plunger to selected position.

Abstract: A fuel measurement and control system for a gaseous fuel engine having a solenoid actuated fuel flow control valve which is electronically actuated to control a desired metering duration when the control system is operating in a fuel flow control mode. The fuel measurement and control system further includes mode control valve for switching the control system between a fuel flow control mode and a positive fuel shutoff mode, wherein the fuel flow control valve is prevented from opening when the control system is operating in a positive fuel shutoff mode. The fuel flow control valve includes a pressure balance chamber to balance the biasing forces acting on the valve from the gaseous fuel, wherein gaseous fuel is introduced into the pressure balancing chamber to provide the balancing forces.

Abstract: Disclosed is a shift valve of a line pressure control system of an automatic transmission used in vehicles. The shift valve comprises a first input line having an orifice; a plug which communicates with the first input line through the orifice; a second input line; an output line which communicates with a hydraulic pressure cylinder; a valve spool for selectively communicating with the second input line and the output line with each other; and an elastic member for balancing the valve spool and the plug.

Abstract: A sanitary water valve having control elements consisting of at least two discs. The first disc is arranged immovably and constitutes the valve seat disc and the second disc, which constitutes the control disc, is arranged movably on the first disc and has a surface conduit for deflection functions which can simultaneously be made to overlap the inflow apertures and outflow aperture on the first disc. The second disc includes one or more depressions which substantially reduce the actuation forces required to open the water valve and as a result, operating efficiency is considerably enhanced.

Abstract: In a device for monitoring the valve stroke of a valve that is pneumatically or hydraulically driven and comprises a valve body that is actuated by means of a pressure spindle (16), in particular, a diaphragm valve, a control spindle (20) is effectively connected to the pressure spindle (16). A control element (38) is arranged on the control spindle (20) in order to actuate a measuring element that serves as a signal transmitter for the valve position. The control element (38) has a control surface (40) that is inclined relative to the actuating axis (z) of the control spindle (20), and a displacement transducer (36) that measures the respective distance from the control surface (40) which corresponds to the valve position is arranged on the valve.This device makes it possible to monitor continuously the valve stroke over the entire range of movement of the valve.

Abstract: A choke valve having a valve body in which is a valve chamber with in inlet and an outlet. A valve seat is carried in the valve chamber. A flow control member is also carried in the valve chamber for axial movement with respect to the valve seat from a closed position, preventing flow of fluids from the valve inlet to its outlet, and selected open positions which provide predetermined flow areas through which flow and pressure throttling of fluids may occur. A non-rotating stem assembly is attached to the control member for axial movement thereof. A valve bonnet is attached to the valve body and provided with a throughbore in which the stem assembly may slidingly reciprocate while positioning the flow control member. A rotating driver assembly is supported from the valve bonnet and includes a nut member threadedly engageable with another end of the stem assembly. The nut translates rotational movement of the driver assembly to axial movement of the stem assembly and the flow control member attached thereto.

Abstract: An apparatus and method for automatic disablement of a pressure relief valve used in connection with a backflow preventer in a fire line. A normally open solenoid valve is included in a pressure sampling line, extending from an inlet, or upstream chamber to one side of the pressure relief valve. A water flow switch, interconnected to a power supply and the solenoid valve, is provided in the fire line. In response to water flowing through the fire line, the switch conducts, actuating the solenoid to a closed position. The solenoid thereby hydraulically isolates the inlet sensor line leading to the pressure relief valve. By maintaining high pressure in this portion of the sensor line, the pressure relief valve is effectively disabled. Thus, even if a check valve malfunction occurs, the pressure relief valve will not open and cannot cause a catastrophic loss of water pressure in the fire line.

Abstract: A pressure balanced gas control valve which uses a bellows to hermetically seal the solenoid from the valve. The gas valve has a valve housing which has an inlet port, an outlet port and a valve seat. Within the housing is a needle valve that moves between an open position and a closed position. The needle valve cooperates with the valve seat to control the flow of gas through the valve. The needle valve is moved to the open position by a solenoid and returned to the closed position by a spring. The bellows is attached to both the needle valve and the housing to prevent gas from flowing into the solenoid and contaminating the solenoid components. The bellows has an effective pressure area which is equal to the needle valve seat area such that there is a net force on the needle valve from the gas pressure that is approximately zero when the needle valve is in the closed position. The net zero force provides a gas valve which does not require additional force to open the needle valve.

Abstract: A bidirectional flow control valve has one port co-axial with a tubular spool and another port opening to the side of the spool, with openings formed in the sidewall of the spool to establish communication between the two ports. The end of the spool adjacent to the one port abuts the brim of a tubular hat-shaped insert which extends inside the lumen of the spool to a closed end on the distal side of the other port. Openings are formed in the sidewall of the insert which are in communication with openings in the sidewall of the spool via an annular groove in the exterior of the insert. The insert reacts against flow forces, helps equalize pressures from one end of the spool to the other, and does not increase the pressure drop across the valve.

Abstract: A hydraulic control valve (10) is proposed which comprises a device (39) for flow force compensation at an outlet control edge (36) and in which the spool sleeve (24) and the associated control spool (11) are of relatively simple construction. By means of control openings (41) and outlet openings (43) separated from one another in the spool sleeve (24), in the region of a deflecting annular groove (42), which deflects the flow behind the outlet control edge (36), in the interior of the spool sleeve, a one-piece construction of the spool sleeve (24) can be achieved, for which no internal machining of the outlet control edge (36) is required.

Abstract: A fuel injection device with a pump plunger which is driven in reciprocation and a working space which is enclosed by the pump plunger, and is connected to an injection valve connected directly to the pump housing. To control the fuel injection quantity and the injection instant, a solenoid valve is provided which is arranged in a fuel passage that is connected to the pump working space and serves for the filling and/or relief of the pump working space. To reduce the volumes subjected to the high pressure, the fuel passage is arranged in such a way that the fuel passage intersects the cylinder bore which accommodates the pump working space, and the solenoid valve is arranged at the entry of this passage.

Abstract: A balanced pressure spool valve has a collector groove formed on the periphery of the valving spool adjacent the valving land, with an annular armature attached to the spool. The collector groove has a radially extending bleed hole which communicates with the axially extending pressure equalization bore in the spool. A solenoid coil upon increased current flow electromagnetically acts on the armature to progressively move the spool and the valving land closes outlet ports formed in the valving bore in which the spool is received. The collector groove intersects the outlet ports to provide bleed flow as the ports are closed by the valving land, thus attenuating the effect of any pressure force imbalance created by the increased flow velocity as the outlet ports are closed.

Abstract: A four way control valve of the type used to control air motors or the like utilizing opposed poppet valve in place of spool valves to reduce tolerance requirements and improve function in standard, balanced and pilot operated versions based on one body.

Abstract: A multi-stage pneumatic pressure regulator establishes a constant output pressure with a change in the output flow. The regulator includes a poppet valve connecting the input and output. A relief valve mounted on the poppet valve includes a first positioning diaphragm subjected to output chamber pressure and a vent hole to atmosphere. A pilot valve is mounted on the relief valve and includes a pressure chamber with a positioning diaphragm of a lesser area than the first diaphragm, coupled to the relief valve and opposing the first position diaphragm. A precision bleed orifice connects the pressure chamber to the input chamber and establishes a precise bleed. A presettable spring load orifice unit in the pilot valve couples the pressure chamber to the output chamber and passes the bleed flow to the output chamber and venting atmosphere. The pilot chamber pressure is greater than the output pressure and prevents feedback of the bleed. The poppet valve and pilot orifice have novel constructions.

Abstract: In a fluid control valve, a valve spool doubling as a plunger of a solenoid is slidably installed on a shaft member, i.e., the valve spool and the shaft member are joined by providing therebetween an annular clearance. The shaft member is formed with three or more pressure chambers and radial restriction holes in constant communication with the pressure chambers. The pressure chambers and the radial restriction holes are arranged at equal circumferential intervals and in constant communication with an outside pressure source so that the annular clearance is maintained uniform, i.e., the valve spool is self-centered relative to the shaft member by the effect of the fluid pressure supplied to the pressure chambers at all times.

Abstract: The valve comprises a first pressure chamber (2), an outlet chamber (6) and a valve body (8), cooperating with a first valve seat (12), and also a second pressure chamber (13) delimited by the valve body. The valve body (8) comprises a control piston (22) which cooperates with a second valve seat (26) and is movable between a closing position and an open position. The control piston delimits in a valve chamber (17) a first sub-chamber, which faces away from the second valve seat (26) and communicates with the first pressure chamber (2), a second sub-chamber, which faces the second valve seat (26) and communicates with the outlet chamber (6), and a middle sub-chamber, which surrounds the cylindrical surface of the control piston and communicates with the second pressure chamber (13). The control piston (22) establishes in the closing position transfer communication between the first and the middle sub-chamber, and in the open position transfer communication between the second and the middle sub-chamber.

Abstract: A four way control valve of the type used to control air motors or the like utilizing opposed poppet valve in place of spool valves to reduce tolerance requirements and improve function in standard, balanced and pilot operated versions based on one body.

Abstract: High pressure valve having a valve cone (12) guided by a valve spindle (10) within a valve housing (1, 2), the sealing surface (13) of the valve cone engaging, in the closed position, an annular ridge (15) of hard metal constituting a valve seat, whereby the sealing surface (13) at least of the valve cone (12) is made of a soft metal, preferrably aluminum.

Abstract: A fluid delivery force-actuated valve, such as a gas delivery pneumatic-actuated valve suitable for use in the electronic industry, employing bellows means so that the actuation means can be used to open or close the valve independent of the force of the pressurized fluid. A method for delivering the pressurized fluid, such as gas, is also disclosed.

Abstract: The present invention discloses a valve which utilises an imbalance of flow induced pressure forces to keep the valve open or closed. The valve has an interior cavity (15) into which an opposite and aligned inlet (12) and outlet (13) open. A bulbous body (16) is located within the cavity and is reciprocally mounted on a spindle (17) which passes through the outlet. Movement of the body increases the flow area at one end of the body and decreases the flow area at the other end of the body. In accordance with Bernoulli's theory this changes the pressures acting on the body (16) giving rise to a net force on the body. A cistern inlet valve (111,211) and cistern (19) are also disclosed.

Abstract: An electro-magnetically operated bidirectional two-way air valve capable of changing state at high pressure differentials or high flow rates in either direction has a body which defines a main bore in which an armature is slidably received. The body has a first port and a second port with a seat between them formed at the end of the main bore and a plastic valve element is secured to a neck portion of the armature to seat against the seat when the valve is closed. Frusto-conical surfaces are formed on the valve element and on the neck portion and a transversely extending pin across the main bore retains the armature in the main bore. In a second embodiment, an end of the armature tapers so as to reduce drag, a powder metal flow restrictor is provided in an axial bore in the armature to reduce shift speed and an elastomer bumper is provided to reduce operating noise.

Abstract: A holding check control valve including a main valve, an assistant valve, a check valve installed in an actuator fluid passage provided at the main valve and provided with a spring chamber, the check valve being adapted to be switched between an opened state for opening the actuator fluid passage and a closed state for closing the actuator fluid passage in response to a pressure difference between the actuator fluid passage and the spring chamber so that the return oil in the actuator fluid passage is returned via a return fluid line provided at the main valve at the opened state, a pair of spaced seat members fixedly disposed in the assistant valve, a hydraulic chamber defined between the seat members, the hydraulic chamber communicating with the spring chamber of the check valve, a plunger extending through the seat members, the plunger being slidable along the seat members between a position closing the hydraulic chamber and a position opening the hydraulic chamber, a pressure setting spring for exerting i

Abstract: A double latching hydraulic valve of the type that either stays open or stays closed at high pressures and only changes state (between open or closed) at low pressures has three ports, with a main valve between the first and second ports which is opened or closed by a poppet. The first port is always in communication with a pressure chamber which biases the poppet against the main valve seat, and the pressure chamber is placed in communication with the third port, which can be connected to tank pressure, only in the open position of the poppet. Thus, a high pressure is provided in the pressure chamber to keep the poppet closed at high pressures, and a low pressure is provided in the pressure chamber to keep the poppet open at high pressures, without excessive leakage through the valve when it is closed.

Abstract: A sealing system for a plug-type unloader includes a bonnet having a guide bore with a stem reciprocably mounted within the guide bore. One end of the stem is affixed to a plug and the other end of the stem is connected to an actuator. A bellows member is positioned around the stem within the plug. The bellows member includes an expandable and contractible bellows having one end attached to the bonnet and the other end attached to the stem. Static seals are provided between one end of the bellows and the bonnet and the other end of the bellows and the stem. The bellows between the ends allows the bellows member to expand and contract as the stem reciprocates within the unloader. No dynamic seals are required. The plug of an unbalanced unloader includes a bore slidingly receiving an adapter around the bellows member to protect the bellows member from the pressure pulsations around the plug.

Abstract: A spray-head for fire fighting having a central bore which communicates with a liquid feed line. A movable spindle is positioned within the bore and has an upper end which sealingly engages the bore. The spindle has a shoulder for defining an annular space between a lower end of the spindle and the surrounding wall of the bore. A second bore extends through the spindle and communicates the annular space with the liquid feed line. The annular space has the same cross-sectional area as the upper end of the spindle, such that the force of the liquid pressure acting on the upper end of the spindle is counteracted by the force of the liquid pressure acting on the shoulder. A spring force is arranged to act on the spindle in the direction of release, and a fusible release element opposes the spring force.