Abstract: A hydraulic distribution valve having two substantially identical, molded plastic shells which are joined at their peripheries to form the distribution valve housing. A shaft is journaled within the housing and extends through one of the shells. A rotor is coupled to the shaft and is rotatably disposed within a rotor chamber defined by the housing. Each shell additionally defines a plurality of axially disposed cavities, where at least two of the cavities of the second shell communicate with the rotor chamber. The second shell also defines an inlet which communicates through a gallery which passes through a portion of the shaft and rotor for communication between the inlet and a control port which is defined by the rotor. The shaft and rotor can be rotated to align the exhaust port with a selected cavity to permit communication between the inlet and the selected cavity.

Abstract: A pivotally adjustable valve disc has a ring seal set in its grooved periphery for contact with a wall of a valve accomodating bore. A flexible, radially expansible member is in the valve groove in a backing relation to the ring seal. Passages admit pressure fluid from the upstream side of the valve disc to the valve groove where the applied pressure is exerted through the radially expansible member toward a radial expansion of the ring seal. In its pressured contact with the seal, the radially expansible member blocks pressure fluid escape through gaps and interfacial joints therein.

Abstract: A three-piece angle stop valve comprises a valve body, resilient control sleeve and handle, with no separate fastening or sealing elements required. Inlet line pressure resiliently biases the side walls of the control sleeve and a circumferential sealing flap formed thereon into sealing engagement with the valve bore to prevent leakage. The handle is secured to the valve body by resilient formations which snap into a circumferential groove on the valve body. The handle rotates the control sleeve by means of telescoping splines. Several circumferential and axial reinforcing ribs are formed on the interior of the control sleeve.

Abstract: A ball valve assembly comprising: a body providing a socket and flow ports communicating therewith; and a core unit comprising a core assembly adapted to be releasably inserted into said socket, the core assembly having a through passage arranged to communicate with said flow ports, and a rotatable ball member within the core assembly, said member having a through passage such that rotation moves it into and out of communication with the passage in the core assembly.

Abstract: A valve assembly for powdery granules comprises a valve housing having upper and lower walls formed with upper and lower openings, a valve member having a hollow cylindrical valve body rotatably supported within the valve housing, and a drive mechanism for turning the valve member through an angular range of about 90.degree. so as to hold the valve member upright in the vertical direction. The valve housing has, at the peripheral edge of its upper opening, a tapered surface which is enlarged downwards, and a circular groove is formed behind the tapered surface. Arranged in the circular groove is an elastic hollow seal ring, part of which is permitted to protrude into the interior of the valve housing through a circular slit formed in the tapered surface.

Abstract: There are disclosed alternative embodiments of a downstream sealing gate valve of the type in which a pair of seats are carried within the body of the valve for sealing between the body and either side of the gate.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable valve member therein that controls ports of a valve seat of the housing through the relative position of a cavity of the valve member relative to the ports, the ports comprising first, second and third ports disposed in spaced apart and straight line relation and the cavity bridging the first and second ports while exposing the chamber to the third port when the valve member is in one position thereof and bridging the second and third ports while exposing the chamber to the first port when the valve member is in another position thereof. The valve member carries a flexible annular sealing member that is disposed between an annular surface of the valve member and the valve seat and surrounds the cavity to seal the cavity to the valve seat while permitting sliding movement therebetween.

Abstract: This invention relates to a pneumatically actuated stepping valve for an automatic control of inlets and outlets for a pneumatic fluid. Each stepping movement is performed in response to a feedback signal indicating that an operation controlled by the valve has been completed. A distributing disc is provided for selecting consecutive pairs of ports consisting of an inlet port and an outlet port each. The stepping valve consists mainly of plastic parts, which contain numerous bores and passages and can be made at low cost. In accordance with the invention the valve disc cooperates with a sealing piston, which in response to pressure applied to said piston establishes connections to through passages of the valve disc, whereas when the piston is pressure-relieved it will be urged by spring means to disengage the valve disc so that the latter will not be restrained by the piston during its stepping movement.

Abstract: Three-piece stop valves, in both angle and straight-through forms, are disclosed comprising a valve body, resilient control sleeve and handle, with no separate fasteners or sealing elements being required. The handle and control sleeve are retained within the valve body by resilient formations on the handle which snap into a retaining groove on the valve body. Inlet line pressure resiliently biases the side walls of the control sleeve into sealing engagement with the valve bore to prevent leakage.

Abstract: A valve seat for use in a ball valve has a shoulder portion, an elastic lip portion, a circumferential non-contact surface, at least one recess and an intersecting portion. The shoulder portion has an engaging surface on its rear surface which contacts the contact surface of the valve casing perpendicular to the flow passage. The non-contact surface is formed on the rear face of the valve seat between the engaging surface and the lip portion and stepped away from the contact surface. The recess is formed in the shape of a groove in the non-contact surface and has its bottom flush with the rear surface of the lip portion stepped away from the contact surface in such a manner that the lip portion is not thinned so as to ensure sufficient strength of the lip portion. The intersecting portion is disposed between the engaging surface and the non-contact surface.

Abstract: A closure-assisted valve includes a cartridge insertable into, and removable from, the remainder of the valve structure. The cartridge includes a displaceable piston having an elastomeric sealing member at one end engageable with a flat-surfaced valve seat. At the other end, the piston includes a drive surface against which a rotatable drive member is engaged. In a preferred embodiment, certain relatively movable portions of the cartridge include a cam surface and a cam follower. The cam surface is contoured such that the piston is advanced toward a valve closed position upon rotation of the drive member, but the last portion of piston travel prior to valve closure is only under the influence of gravity and fluid forces. In order to bias the piston toward a valve closed piston, entering fluid is directed around the piston so as to aspirate the piston toward a closed position.

Abstract: A bidirectional rotary valve capable of use in high pressure flowpaths includes a pair of removable end retainers defining aligned ports and having a single rotatably mounted disc closely positioned therebetween. The disc has ports corresponding to those of the end retainers and is operated by link means coupled to an operating rod slidably mounted in the valve body. Rotation of the disc changes the alignment between its ports and those in the end retainers for controlling flow. The disc is loosely mounted on a bearing pin that is also loosely fitted in the end retainers to permit slight lateral movement of the disc and ready disassembly of the valve. The disc is constructed such that it will flex to a greater degree for a given pressure than the end retainers.

Abstract: This disclosure sets forth a variable tensioning system for use in a valve featuring shear seals. In the preferred and illustrated embodiment, a spring system provides loading on the valve element to force that element into engagement with a valve seat. A sliding sealing surface is accomplished in this contact. The valve element may be a tapered plug, a sphere or a flat face or plate. Typically, it is a hard member working against a seat supporting a seal surface featuring a sliding shear seal. A specific minimum load is applied to the valve element to accomplish sealing against minimum pressure. The present apparatus incorporates a closed chamber enclosing a slideable piston. The piston has a specific cross-sectional area exposed to fluid pressure of the fluid being controlled by the valve. The piston applies pressure dependent force against the valve element.

Abstract: A rotor valve has a set of sealing members or inserts positioned in longitudinal channels formed on the outer surface of a cylindrical rotor. A resilient O-ring snuggly engaged in a groove in the rear surface of each insert urges it against a surrounding rotor chamber formed in a valve body. Due to the resilience of the O-ring, the fluid seal between the rotor and the rotor chamber does not bind due to contaminants or extreme variations in temperature. The sealing inserts are formed of a deformable material. Fluid pressure acting on the inserts deforms them to produce a lateral squeezing force on the O-ring. The interaction between the inserts and the O-ring enhances the integrity of both the seal between the inserts and the surrounding rotor chamber and the seal established by the O-ring itself between the rotor and the insert.

Abstract: The valve comprises a two-piece housing consisting of a body and a flat cover. The body is milled out to define a working chamber. A port extends through the body wall to communicate with the chamber; a second port extends through the cover wall. The two ports are aligned at one side of the chamber, so that the remainder of the chamber provides a storage cavity. A gate valve comprising a stem and gate is wholly contained within the chamber. The base of the stem is pivotally connected on a shaft journalled in the housing, so that the gate may be rotated or swung along an arc from the storage cavity to a blocking position across the ports. Disengageable means are provided to normally lock the gate valve in the stored position. Means are also provided to bias the gate valve to the blocking position when the locking means are disengaged. The assembly is flat and compact and is particularly adapted to fit in the crowded confines of an engine.

Abstract: Disclosed is a seal for a rotary hydraulic valve having an inner surface which is concave and spaced from the recess in the rotary core in which it is received. Two parallel troughs are formed in the inner surface between the edges thereof and the central flow passageway. In use, fluid under pressure enters the trough and distorts the seal both radially outwardly against the valve body and circumferentially outwardly against the sides of the seal recess.

Abstract: A high pressure bidirectional flow throttling valve includes a pair of rotatable throttling discs mounted in a cavity for slight lateral movement in the flowpath. The operating mechanism for rotating the discs includes a toggle arrangement located outside the flowpath.

Abstract: A plug valve has an actuating stem which is non-integral with the valve plug. The actuating stem is axially movable with respect to the valve plug to compressingly and sealingly engage an external sealing member in response to fluid pressure. The plug wedges itself into sealing engagement in response to fluid pressure.

Abstract: A diverter valve assembly includes a valve body rotatably mounted in a cavity of a housing. The housing has an inlet connected to a water supply, a tub spout outlet, and a showerhead outlet. The showerhead outlet is connected to a showerhead via a riser. The valve body has a jet orifice in communication with the inlet and alignable with one of the outlets. The valve body also has a flange which rotatably seats an elastomeric sleeve. The sleeve, when the jet orifice is aligned with an outlet, is aligned with the other outlet. The sleeve and flange form a pressure chamber which is in communication with the inlet. When the sleeve is aligned over the tub spout outlet, and the water supply is turned on, the back pressure caused by the showerhead flexes the sleeve to seal the tub spout orifice. When the water supply is turned off, the elastomeric sleeve relaxes to allow water to drain from the riser to the tub spout without the valve assembly changing position.

Abstract: A double disc variable orifice valve is provided for fluid solids service in a petroleum process conduit wherein each disc thereof is provided with a plurality of equally spaced and equally sized apertures extending therethrough. One of the discs of the valve is fixed relative to the surrounding valve conduit. Adjacent to the fixed orifice disc or plate, there is provided an adjustable orifice plate having a similar number of sized and spaced orifices. The adjustable orifice plate is supported at its center from the fixed orifice plate in a pivotal mounting arrangement which may include a central fixed aperture.

Abstract: A fabricated ball valve is positioned between the inlet and the outlet of a valve housing and includes a first tubular member having sealing faces on each end for seating on valve seats and providing flow therethrough when the first tubular member is aligned between the inlet and the outlet. Second and third tubular axially aligned members have one end connected to the outside of the first member and have sealing faces on their other ends for seating on the valve seats. The second and third members block flow through the valve when the second and third members are aligned between the inlet and outlet. Sealing means may be on either the valve seats or on the movable seat ring connected to each of the other ends of the second and third tubular members.

Abstract: A ball-type valve comprises a rotary valve member in a housing or valve body whose ducts communicating with the passage in the valve member are provided with respective sealing devices. These sealing devices comprise elastomeric formable rings received in blind recesses around the respective ducts and communicating therewith by orifices opening behind each deformable ring so that the fluid pressure in the respective duct under pressure will urge the deformable ring against the annular gasket and press the gasket against the rotary valve member.

Abstract: An engine air intake shut-off valve utilizing a loose-fitting gate member is disclosed. The shut-off valve is of the sliding gate type in which a gate member is reciprocable between an open and a closed position. The gate member is dimensioned smaller than the interior of the valve housing to provide a clearance for smooth operation after dirt has accumulated in the housing. The gate member is loosely connected to a reciprocating cylinder which permits the gate member to move along the direction of air flow to seat against either of two opposed seating surfaces in the valve housing.

Abstract: A rotary plug valve has hydraulically actuated seals for sealing between a valve body and a rotatable valve plug. The valve plug is rotated to open or close the valve. A valve handle for turning the plug can be rotatably uncoupled from the valve plug when the valve is closed and turned relative to the plug toward an overtravel position to actuate a hydraulic piston to pressurize the seals. A second piston regulates pressure to the seals and prevents overpressurization.

Abstract: A guillotine damper for use in exhaust or like duct systems which must be entered by men for servicing has its frame provided with guides extending about the flow path from one end of the opening by which the blade enters an air tight bonnet to the other end thereof and enclosed by resiliently flexible metal seals. The blade has marginal channels coextensive with the guides with the channels closely fitting the guides and compressing the sides of the seals with zero leakage attained by sealing air discharged along the channels during movement of the blade and while the damper is closed.

Abstract: A plug valve for controlling discharge of a fluid tank has an upper surface continuously subjected to the weight and pressure of the tank's contents. Pressure applied to this upper surface is transmitted through the valve to assist sealing with a member subjacent to the valve's plug.

Abstract: A sluice valve arrangement is adapted to make an air-tight partition or communication between a vacuum treatment chamber and the atmosphere or a pre-chamber. This arrangement includes a valve seat member comprising a cylindrical or spherical member having therein an opening, a pair of guide rails attached to the inner circumference of the seat member, a valve member movably supported on the guide rails, and means for air-tight engagement of the valve member and the valve seat portion of the seat member. The valve member has a curvature equal to that of the cylindrical or spherical member, and the engagement means comprises a plurality of bellows expandable by a compressed gas or air.

Abstract: A valve comprises a hollow body having an inlet and an outlet, a seat ring in the outlet provides a face adapted to engage a gate, a closure mounted for movement relative to the seat ring and including a carrier having a passage therethrough in which are slidably disposed a lipped gate disc adapted to engage the seat face and block the outlet when the valve is in closed position, a pressure spring pressing the gate disc against the seat face when the valve is in closed position, and a ball transferring the reaction of the spring to the body.

Abstract: The plate valve has a housing forming an inlet spigot and an outlet spigot. A movable valve member provided with a closure plate and an orifice plate is movable radially of the spigots via servo-pistons which are rigidly connected to the valve member. The pistons are guided in cylinders disposed diametrically opposite one another on the spigots. The cylinders may be integrally formed with the plate valve housing or may be separably formed as cylinder heads.

Abstract: A feed water check valve of the swing type is provided with a soft seal backup to the main element to ensure sealing of the valve plug so that no leakage occurs during testing or when full closure is required as in an emergency.

Abstract: A rotary pump and flow control valve assembly (73) are disclosed. The pump includes a pumping element (17) defining fluid pockets (31), a discharge port (59) and a discharge fluid path (57). The flow control valve assembly is disposed in a valve bore (71) and includes a valve spool (83) having a spool land (105) disposed between the discharge path and a bypass bore (81). The spool land includes a cylindrical wall portion (109) and an annular wall portion (111) extending from the spool to the cylindrical wall portion. The wall portions define an annular fluid chamber (115) in communication with the discharge path. The wall portions are relatively thin such that the cylindrical wall portion expands radially when the annular fluid chamber communicates with fluid at relatively higher fluid pressure. The result is a reduction in the normal clearance between the cylindrical wall portion and the valve bore, reducing leakage past the spool land.

Abstract: A rotary fluid pressure device (11) is disclosed of the type including an internal gear set (17) defining expanding and contracting volume chambers (29). The device further includes a stationary valve member (19) and a rotary valve member (55) having engaging valve surfaces (71,73). A valve seating mechanism (75) includes an annular balancing ring member (77) having a valve-confronting surface (78) engaging an opposite surface (68) of the rotary valve. In accordance with the present invention, it has now been recognized that stalling of the device is normally caused by separation of the balancing ring from the rotary valve, rather than lift-off of the rotary valve from the stationary valve. There is disclosed several ways of modifying the valve seating mechanism to prevent substantial flow of leakage fluid through the balancing passages (107) which, in turn, causes a substantial pressure differential across the balancing ring, and separation of the balancing ring from the rotary valve.

Abstract: A rotary lift-turn type plug valve mechanism includes a valve body and bonnet structure defining a tapered valve chamber that receives a tapered plug member which is operated by linear and rotary components of movement to achieve valve operation. Externally adjustable plug positioning means is provided by the valve mechanism to enable the position of the plug element to be adjusted relative to the inlet and outlet flow passages defined by the valve body. Plug dampening means is also provided for applying a dampening force to the plug element to prevent slamming of the plug upon reaching the end of a rotational component of movement. A valve actuator is also provided that operatively engages the valve stem of the plug and is capable of imparting both linear and rotary components of movement to the valve stem for unseating, rotating and reseating the valve element within the valve chamber.

Abstract: An annular seat for use in a ball valve has two groups of pressure relief passageways each of which extends completely through the seat between its front and rear faces. The relief passageways in one group are located adjacent the outer periphery of the seat. The passageways in the second group are located radially inward of the passageways in the first group, and extend between the rear face of the seat and a curved sealing surface on the front face of the seat. A pair of such seats are disposed in a ball valve housing adjacent opposite sides of a rotatable ball. The interior seat support surfaces in the housing have machined recesses adjacent the central axial fluid passageway through each seat, to facilitate lip flexure of the seats. The overall arrangement provides a bidirectional valve which seals on the downstream side only of the valve, and which relieves excessive cavity pressure in the valve past the upstream seat.

Abstract: A flow control valve assembly for closing an inlet into a housing through which powdery or granular material is flowing and for sealing said inlet once closed, the assembly comprising a closure member movable within the housing from an inoperative position in which the inlet is open into a normal operative position closing said inlet, during which movement a deformable sealing ring mounted in the housing to surround the inlet wipes over, to clean, the closing surface of the closure member and to make initial sealing contact with the closure member. Inflation of the sealing ring against the closure member in its normal operative position then supplements the seal while, on subsequent pressurization of the interior of the housing, the closure member is displaced bodily within the housing axially towards the inlet to make increased contact with, to supplement further the seal with, the sealing ring.

Abstract: A gate valve having an expandable valve closure apparatus which is capable of expanding to seal two oppositely located parts in its valve housing. The expandable valve closure apparatus if pivotally mounted for movement on the end of a swing arm member to permit the expandable valve closure apparatus to be moved from its operative position in the vicinity of the ports in the valve housing to its inoperative or stowed position within the valve housing. Expansion of the expandable valve closure apparatus is accomplished by compressed air that is fed into a bellows that forms part of the expandable valve closure apparatus. Contraction of the expandable valve closure apparatus is accomplished by permitting the compressed air to be released from within the bellows and by springs which form part of the expandable valve closure apparatus. Air pressure is also utilized to move the expandable valve closure apparatus from its operative to its inoperative position and from its inoperative to the operative position.

Abstract: A valve comprising an elastically flexible diaphragm and an annular stopper, the stopper being adapted to control shifting and flexion of the diaphragm under fluid pressure when the valve is closed in such a manner that the stopper abuts against the diaphragm intermediately between a part thereof contacting a valve diaphragm seat and a part thereof connected to a valve closure member.

Abstract: A metering and distribution valve assembly is proposed for a fuel injection system of an internal combustion engine. The metering and distribution valve assembly includes a control slide having a head 68 and a control edge and a slotted sleeve with at least two control slits. The control edge opens the control slits to a greater or lesser degree in accordance with the relative motion between the control slide and the control slits in the slotted sleeve. An end face of the control slide adjacent to the control edge is exposed to a control pressure which is lower than the system pressure engaging the control edge. The pressure drop at the circumference of the control slide head formed between the control edge and the end face is capable of being influenced in such a manner that the control slide head rests unilaterally on the slotted sleeve at least during a portion of the displacement movement. As a result, better metering precision is obtained.

Abstract: A high vacuum valve comprises a casing having a valve inlet port and a va outlet port connected to the inlet port with a valve seat defined between the inlet and outlet ports. The casing also defines a valve movement passageway and a valve member is movable in the housing along the passageway between a position in which it is aligned with the valve seat for closing the valve and one in which it is out of alignment with the seat to open the valve. The valve member includes two separate relatively movable plate parts both of which move along the passageway together and one of which is movable when the valve member is aligned with the valve seat so as to move into engagement with the seat.

Abstract: A gate valve apparatus suitable for controlling the flow of fluids in a conduit, especially gases in high temperature applications, is disclosed. The apparatus includes a gate member adapted for sliding movement through an aperture in the gate valve assembly. Each opposing side of the aperture has fixedly mounted cooperating flat sealing strips to seal the aperture in both the conduit-open and conduit-closed positions. In certain embodiments a plurality of substantially parallel gate members, each having aperture sealing means, may be used to provide increased sealing effectiveness for highly toxic gaseous mediums.

Abstract: A cock for controlling the heating system of a motor vehicle has a flat valve member controlled by a lever. Under operating conditions said valve member is permanently biased by the pressure of the heating liquid against a sealing ring provided in the seat of the valve member in the cock housing and the control lever is connected to the pin of said valve member by means of a screw, the screw serving as a secondary means for biasing the valve member.

Abstract: A reversing valve construction having a housing provided with a chamber carrying a movable valve member therein that controls ports of a valve seat of the housing through the relative position of a cavity of the valve member relative to the ports, a one piece flexible sealing skirt being carried by the valve member and extending outwardly therefrom in a cantilevered manner adjacent the valve seat so as adapted to be exposed to fluid pressure in the chamber that will act directly thereon and cause the flexible skirt to flex and engage the valve seat in a manner to tend to sealingly conform to the contour of the valve seat and thereby seal the cavity to the valve seat while permitting sliding movement therebetween. A spring in the housing acts on the flexible skirt to urge the same toward the valve seat.

Abstract: A valve structure for use in a two handle faucet environment includes a sleeve and a valve member positioned within the sleeve and rotatable therein. The sleeve has an inlet and an outlet and a path of flow therebetween. The valve member has an opening which is used to connect the inlet and outlet and thus form a part of the path of flow. An annular seal member is fixed on the valve member and spaced from the opening, which seal member is used to close off communication between the inlet and outlet. At no time is the path of flow through the seal member, thus preventing any excessive pressures being applied to the seal.

Abstract: A valve assembly embodied in cartridge form for ease of manufacture, repair, and replacement and for retrofitting existing valve housings. The cartridge operates with shear on/off operation and includes a valve element having elastomeric properties and a configuration arranged to develop positive shut-off and seal action to prevent leakage in both the flow circuit and along an operating stem.

Abstract: An improved valve is disclosed. In the preferred and illustrated embodiment, the valve utilizes a flat disk within a valve body, the disk supporting a peripheral groove having bearings therein for alignment and to enable rotation, and further includes pressure balanced opposing faces and receives a valve seat therein. The flat disk and body arrangement reduces the size of a large valve and reduces the wear occurring on the valve seat and seal mechanism. Alternate embodiments and configurations are disclosed.

Abstract: A rotary lift-turn type plug valve mechanism includes a valve body and bonnet structure defining a tapered valve chamber that receives a tapered plug member which is operated by linear and rotary components of movement to achieve valve operation. Externally adjustable plug positioning means is provided by the valve mechanism to enable the position of the plug element to be adjusted relative to the inlet and outlet flow passages defined by the valve body. Plug dampening means is also provided for applying a dampening force to the plug element to prevent slamming of the plug upon reaching the end of a rotational component of movement. A valve actuator is also provided that operatively engages the valve stem of the plug and is capable of imparting both linear and rotary components of movement to the valve stem for unseating, rotating and reseating the valve element within the valve chamber.

Abstract: A valve including a fluid port; a valve seat round the port; and closure means movable towards and away from the seat, the closure means including a sealing surface engageable with the seat and a protrusion which extends from the sealing surface towards the seat, the protrusion being operative to create an accelerated flow of fluid between the seat and the sealing surface prior to the latter engaging the seat upon movement of the closure means towards the seat and the protrusion further being adapted for at least part thereof to be urged into sealing engagement with the surround of the port by pressure in the valve when the sealing surface engages the seat.

Abstract: A valve assembly for a fluid filter includes a rotatable valve spindle movable with respect to the value housing and having first and second channels communicating with the filter, the channels also communicating with first and second bores of the housing when the spindle is in a first position in which fluid flows through the filter. The valve spindle further includes a third channel to provide a bypass around the fluid filter when the spindle has been rotated to a second position. The valve spindle also includes seal means for sealing the first and second bores when in the second or filter bypass position, which means includes a pair of chambers arranged to be aligned with the bores and a seal member within each chamber arranged to seal the respective bores. Each seal member has an aperture providing communication between its chamber and its respective bore to allow fluid to enter and charge the chambers for forcing the seal members against the bores in fluid tight sealing engagement therewith.

Abstract: A compact, hydraulically operated pressure valve for selective opening and closing of conduits or the like is provided which can withstand extremely high pressures in use, is easily repaired and/or replaced, and is low in cost. The valve includes a thin, circular metallic diaphragm which is mounted for bulging in response to pressure directed thereagainst, along with cavity structure adjacent to and in communication with one face of the diaphragm; in use when the diaphragm is located in closing relationship to a pressurized conduit, hydraulic fluid directed to the chamber establishes a desired pressure differential across the diaphragm such that the latter experiences only a desired pressure. The bulging of the diaphragm also causes the latter to sealingly engage a sharp marginal sealing edge associated with the valve, to further enhance the integrity of the closure effected thereby.

Abstract: A hydraulic valve is disclosed which has a gasket sealing against and, to a limited extent axially movable on, a movable valve member. The valve member has a radial shoulder sealing surface which is spaced from a matching, larger diameter concentric radial shoulder sealing surface of the body of the valve. The sealing surfaces can be aligned with each other by an axial movement of the valve element, with a radial spacing between them providing a fluid passageway. The gasket has an angular cross-section, with the apex being toward where the sealing surface of the valve element adjoins the valve element surface over which the gasket extends outward from the axis of the valve element. The angular relationship between the aligned sealing surfaces and the sealing portion of the gasket is such that when the gasket is moved toward the sealing surface of the body by the valve element, the outer lip of the gasket sealing portion first contacts the surface, thus significantly blocking fluid flow.