Abstract: The invention provides a fluid coupling for coupling a fluid source with a fluid supply line. The fluid coupling comprises a gladhand mounted to a body via a swivel connection. The gladhand is movable between a stored and protected position, wherein an outlet of the gladhand rests against a rubber cup to prevent fluid flow therefrom, and a use position, wherein the gladhand is removed from the rubber cup and can be connected to a fluid supply line. Additionally, the fluid coupling comprises a valve assembly preferably disposed in the body. The valve is operable between open and closed positions to effectively turn the fluid coupling on and off.

Abstract: A control valve of the ball type with bi-directional shutoff capabilities is disclosed. The ball valve including an inlet and an outlet, a ball element and a seal assembly. When closing the valve, the ball element, which is eccentrically mounted on a shaft, rotates to abut the seal assembly. While closed, the seal assembly including a seal housing, a main seal and a resilient member, contacts the ball element at the main seal, while the resilient member biases the main seal toward the ball element. The seal assembly further includes a secondary flowpath between the main seal and seal housing, which is restricted by two unidirectional seal rings.

Abstract: A ball value has a valve body defining a cavity, a ball closing component disposed within the cavity through a cavity opening, a cover, and seal assemblies having seating rings with seals disposed engaging both sides of the ball closing component. The seating rings slide in recesses of the valve body into and out of engagement with the ball closing component. The seating rings have flange with seals each engaging a side of the corresponding recess. A closing ring is screwed into the cavity to engage the seating rings. The flange of the seating ring defines a working chamber with the recess and the closing ring. The working chamber is communicated with a pressurized medium source and the working chamber is pressurized to displace the seating rings from the ball closing component to allow seal replacement.

Abstract: An isolation valve assembly for use in a pipeline comprises a valve housing (1) body having inlet (12) and outlet (13) openings. In the housing there is disposed a pair of independently operable rotary valve balls (3) each having a port (25) therethrough The valve balls (3) are each rotatable between an open position in which the respective port is in communication with the adjacent opening and a closed position in which the valve ball closes the adjacent opening. A valve seat (9, 14) supports each valve ball in the housing and a valve seat retention member (10) is disposed in each of the openings (5). The retention member (10) defines a flow passage (11) therethrough for communication with the adjacent valve ball port and has a first end proximal to one of the valve balls. The first end supports said valve seat and a second end has means for engagement to the pipeline. The arrangement allow a relatively large bore valve assembly to have a length conforming to International Standard ANSI B16.

Abstract: A rotor valve (10) having a rotor seal (34) containing a centrally disposed opening (52) for directing an external pressure (Pe) to a rear surface (35) of the seal for applying a sealing force against a sealing surface (36). A projection (38) of the seal surrounding the opening is disposed within a bore (40) formed in a rotor (14) of the valve. An O-ring seal (44) defines the portion of the rear surface exposed to the external pressure. The rotor may be supported on one end by a bearing assembly (80) and may be open at the opposed end for receiving incoming water. Circumferentially distributed slip-surface plugs extend radially beyond the diameter of the rotor to support the rotor along an interior surface (39) of the valve body (12).

Abstract: A valve arrangement for a vacuum pump includes a valve head displaceable substantially perpendicular to a flow direction of a fluid through the valve arrangement, a valve seat, and a valve spring for biasing the valve head into a flat abutment engagement with the valve seat, with the valve spring being formed of at least one substantially hollow body made of an elastomeric material.

Abstract: A flow-controlling device is provided for controlling the flow of a fluid. The device comprises a housing, a flow-control element disposed within the housing, at least one seat operably engaging the flow-control element, a biasing device operably engaging each seat for urging the seat into sealing engagement with the flow-control element, and an actuating device operably engaging the flow-control element. The seat operably engages the flow-control element and the biasing device operably engages the seat to urge the seat into a sealing engagement with the flow-control element. The flow-control element, the seat, and the biasing device are comprised of a refractory and/or toughened ceramic material that is fully annealed so that porosity in the material is substantially eliminated and such that the material is substantially homogenous. Components fabricated from such a ceramic are generally heat, corrosion, and wear resistant and are capable of substantial elongation without failure.

Abstract: A four port reversing valve for a reversible-cycle refrigeration system having a compressor is constructed with the reversing valve having a first inlet port adapted to be connected to the compressor and second, third, and fourth ports. The four port reversing valve is further provided with a valve member operable between first and second positions. The valve member in its first position connects the first inlet port with the second port and the third port with the fourth port, and the valve member in its second position connects the first inlet port with the fourth port, and the second port with the third ports. The second and third ports and the third and fourth ports are arranged so that the angle between the ports is about 135°. In one embodiment the valve member rotates, and in another it translates linearly. Several means are disclosed for actuating the valve member.

Abstract: A top-entry ball valve assembly that includes top and bottom camming plates which are coupled to top and bottom shoulders of the ball valve member. The camming plates include a first pair of opposing camming corner-surfaces to displace the spring-biased valve seat from the perimeter of the ball valve member when it is rotated between open and closed positions. The plates further include a second pair of opposing camming corner-surfaces to fully retract the spring-biased valve seat when being serviced so that the retraction tool can be inserted to hold the seats in place with little or no damage to the forward end of the seats.

Abstract: A control valve of the ball type with bi-directional shutoff capabilities is disclosed. The ball valve including an inlet and an outlet, a ball element and a seal assembly. When closing the valve, the ball element, which is eccentrically mounted on a shaft, rotates to abut the seal assembly. While closed, the seal assembly including a seal housing, a main seal and a resilient member, contacts the ball element at the main seal, while the resilient member biases the main seal toward the ball element. The seal assembly further includes a secondary flowpath between the main seal and seal housing, which is restricted by two unidirectional seal rings.

Abstract: A cylindrical housing has a flange at an exterior end, male threads in an external surface remote from the flange, and a small axial hole, and female threads in an internal surface remote from the flange. A disk shaped fastener has internal threads rotatably supported upon the male threads of the housing. The fastener rotates to secure a prosthetic limb adjacent to the flange for operation and use and to allow separation of the limb from the housing. A cup-shaped end plug has a side wall with male threads receivable in the female threads of the housing and an end face with an axial opening. A plug with a pull string is positionable within a partly spherical surface adjacent to the interior end of the housing. A coil spring is positioned between the end plug and the spherical plug.

Abstract: The invention is directed to a plug valve comprising a body which includes an inlet port, an outlet port and a cavity that is connected between the inlet and outlet ports; first and second seal segments which are mounted in the cavity and which each comprise a through bore that is coaxial with the inlet and outlet ports; the through bores and the inlet and outlet ports defining a flow passage through the body; a plug member which is rotatably positioned between the first and second seal segments and which includes a hole that extends transversely therethrough; the plug member being rotatable between an open position in which the hole is aligned with the flow passage and a closed position in which the hole is offset from the flow passage; and at least a first booster spring which is positioned between the first seal segment and the body to bias the first seal segment against the plug member.

Abstract: A ball valve includes a valve body and an urging member. The valve body is formed of a valve block, and two leakproof rings. The urging member is formed of a movable block, a locating element, and an elastic element located by the locating element. The movable block is provided with two slots for locating the leakproof rings, and with two annular protruded edges. In the event of deformation of the leakproof rings, the leakproof rings are pushed by the elastic element to make contact with the valve block. In the event that the leakproof rings are melted by fire, the valve block is pressed against by the annular protruded edges, so as to minimize the leakage of the ball valve.

Abstract: The invention is directed to a plug valve comprising a body which includes an inlet port, an outlet port and a cavity that is connected between the inlet and outlet ports; first and second seal segments which are mounted in the cavity and which each comprise a through bore that is coaxial with the inlet and outlet ports; the through bores and the inlet and outlet ports defining a flow passage through the body; a plug member which is rotatably positioned between the first and second seal segments and which includes a hole that extends transversely therethrough; the plug member being rotatable between an open position in which the hole is aligned with the flow passage and a closed position in which the hole is offset from the flow passage; and at least a first booster spring which is positioned between the first seal segment and the body to bias the first seal segment against the plug member.

Abstract: A ball valve includes a valve body, a cap, a disk spring, a driven member, and a spherical body. The disk spring and the driven member are disposed in the cap such that the driven member is urged by the disk spring to displace, thereby causing the driven member to push PTFE washers to come in contact with the spherical body.

Abstract: A valve for controlling the flow of a fluid comprises a housing, a flow-control element disposed within the housing, at least one seat operably engaging the flow-control element, and a biasing device for urging the seat and the flow-control element relative toward each other. In some embodiments, the valve also includes an actuating device operably engaging the flow-control element. The flow-control element, the seat, and the biasing device are comprised of a refractory material, and at least the biasing device is formed of a toughened refractory or ceramic material that is fully annealed so that porosity in the material is substantially eliminated and such that the material is substantially homogenous. In some embodiments, the seat, the flow-control element, the biasing device, and/or other components may be advantageously fabricated together as a unitary structure. An associated fabrication method is also provided.

Abstract: A four way valve which is relatively easy to manufacture and which is smaller than conventional four way valves for a given bore size or flow capacity. The valve can be formed utilizing a closure having a pair of intersecting bores, with a separator provided within the closure to form two isolated passageways or flow paths. An improved sealing/seating arrangement is also provided.

Abstract: A valve for controlling the flow of a fluid comprises a housing, a flow-control element disposed within the housing, at least one seat operably engaging the flow-control element, and a biasing device for urging the seat and the flow-control element relative toward each other. In some embodiments, the valve also includes an actuating device operably engaging the flow-control element. The flow-control element, the seat, and the biasing device are comprised of a refractory material, and at least the biasing device is formed of a toughened refractory or ceramic material that is fully annealed so that porosity in the material is substantially eliminated and such that the material is substantially homogenous. In some embodiments, the seat, the flow-control element, the biasing device, and/or other components may be advantageously fabricated together as a unitary structure. An associated fabrication method is also provided.

Abstract: A stem valve stopper that has a shell (1) intended to be mounted to a faucet (K). An operating stem (8) is mounted for rotation but is axially fixed in the stopper shell (1) and has a lower end that acts as a valve seat surface (12). The stem 8 has an interior section (7) that is threadably engaged with a mobile fitting (6) that is mounted in the shell so that it can be moved axially but cannot be turned or rotated inside the stopper shell. The mobile fitting (6) has an annular lower end surrounding a valve seat (12). A valve sealing member (17) made from elastomeric material is mounted in the lower end of stopper shell (1) and is spring biased downstream toward the valve seat (12). The mobile fitting (6) can be operated to push the sealing member (17) upstream away from valve seat surface (12) and provide flow about the valve seat (12).

Abstract: A flow-controlling device is provided for controlling the flow of a fluid. The device comprises a housing, a flow-control element disposed within the housing, at least one seat operably engaging the flow-control element, a biasing device operably engaging each seat for urging the seat into sealing engagement with the flow-control element, and an actuating device operably engaging the flow-control element. The seat operably engages the flow-control element and the biasing device operably engages the seat to urge the seat into a sealing engagement with the flow-control element. The flow-control element, the seat, and the biasing device are comprised of a refractory and/or toughened ceramic material that is fully annealed so that porosity in the material is substantially eliminated and such that the material is substantially homogenous. Components fabricated from such a ceramic are generally heat, corrosion, and wear resistant and are capable of substantial elongation without failure.

Abstract: A zone valve for use in a hydronic system, the valve including a ball element through which liquid flows in an axial direction, a valve casing enclosing a ball element, a valve seat in contact with the ball element and the valve casing, the valve seat having a notch to receive an O-ring, an O-ring installed in the notch, and wherein the notch has a surface inclined with respect to the axial direction so that an axial force on the valve seat causes the O-ring installed in the notch to be compressed to improve a seal between the valve seat and an internal bore of the valve casing.

Abstract: A gate valve is disclosed having a telescopingly interfitted seat assembly that fits into a recess in a gate chamber between the gate valve body and the gate. A sealing cavity is formed between two seat elements that form the telescopic connection. A preferably unidirectional seal is disposed therein having two lip seals. The unidirectional seal is preferably oriented to allow leakage for a pressure differential wherein the gate chamber has a higher pressure than the pressure on the opposite side of the seal from the gate chamber. The seal is preferably made of non-permeable material and the material is preferably flexible but non-elastic with little or no memory. Additional such seals may be used for sealing with the gate valve body. In one embodiment, an expansion member is provided for extending into an open end of the seal to expand the two lip seals.

Abstract: An valve actuator in a hydronic heating and cooling system includes a motor for changing the position of a valve, a switch for switching power to the motor, and a sensor for detecting the arrival of the valve at a desired position and for stopping the motor without using a mechanical stop. The motor's power source includes a capacitive power source which can be used to drive the motor under low-power conditions. A worm gear is used in the drive train, and combined with a clutch assembly to permit the valve to be operated manually.

Abstract: An improved valve fitting configured to limit pressure exerted upon a surface of the valve by a sealing surface of the fitting to inhibit the sealing surface from deforming causing the valve to leak is provided. This causes the sealing surface of the fitting to exert a constant pressure upon a sealing surface of a valve body, when the fitting is coupled to the valve body, to form a continuous seal between the fitting and the valve, to inhibit leaks therebetween. When the fitting is coupled to the valve body, the compression member is compressed to limit the pressure that the sealing surface exerts on the valve body, to inhibit the sealing surface from distorting, or deforming, against internal componentry of the valve which can form gaps between the sealing surface and componentry, causing the valve to leak.

Abstract: Apparatus for coordinating the positions of valves in a pair of air flow passages along a jet engine nacelle to control two rotary valves from a single linear actuator. Each of the valves is of a ball type which is rotatable within a housing to achieve variable flow control in accordance with the particular shape of the opening through the rotatable valve member which varies with valve member rotation. The valve member bore shape may differ for the two valves, as well as the angle of the linkage between the linear actuator and each valve, to achieve different flow control relationships for the two valves from the single actuator armature. Each valve incorporates a pressure balancing member at the inlet seal of the valve which results in a reduction of the force of the seal element against the rotatable valve member when the valve is in the closed position, thereby reducing the torque required to rotate the valve out of the closed position.

Abstract: A ball valve for controlling the flow of a fluid is provided having primary and secondary annular sealing seats which are disposed in the body cavity for the purpose of providing a seal between the valve body and a first hemisphere of a ball. An annular leak detection channel is defined between the primary and secondary annular sealing seat for collecting fluid that leaks past the primary sealing seat. A purge is defined in the valve body extending from the channel to the exterior of the valve body, for establishing fluid through-flow and for draining fluid away from the secondary sealing seat that collects in the channel. A third annular sealing seat sealingly engages a second hemisphere of the ball.

Abstract: A gas valve seat is provided with a control chamber in which a control device is disposed. The control device includes a valve body, a fitting ring, an elastic element, and a rotary plug. The valve body is urged by the elastic element to locate securely between the fitting ring and the rotary plug such that the wear of the valve body is effectively minimized.

Abstract: A metering device includes an inlet and outlet for a material (liquids, gases or solid particles) to be metered, a rotatable ball driven by a shaft and interposed between the inlet and outlet seats. The rotatable ball has a transverse bore containing a sealess shuttling member which can reciprocate back and forth along the bore between two sealing seats so as to seal against one or the other. The sealess shuttling member is propelled by pressurized material which flows into the bore without surface-to-surface contact of the shuttling member with the bore wall until is engages one of the two sealing seats. Each time the rotatable ball rotates 180.degree., a metered shot is ejected resulting in a quasi continuous flow depending upon a rotatable ball revolution rate.

Abstract: A plug with retaining packing for a water faucet cartridge where the packing is made in one piece on both sides of the plug. Both the portion of the packing that is on one side of the plug and the portion of the packing that is on the other side of the plug have a part of their surface in contact with and resting on the plug with respect to the axial direction of the plug and being connected to each other by at least one connection portion that extends substantially in an axial direction in a peripherally continuous manner or by sections through appropriate openings in the plug. The packing is formed and shaped on the plug by injecting an elastomer in the liquid state and cross-linking the elastomer.

Abstract: A rotary coupling for communicating a pneumatic signal from a stationary pneumatic source to an apparatus. The rotary coupling has a housing and a rotating portion that rotates with respect thereto. The housing has at least two inlets in fluid communication with the pneumatic source. The rotating portion has at least two outlets in fluid communication with the apparatus. Inlet and outlet pairs are aligned radially relative to an axis of rotation of the rotating portion so that they are in fluid communication when the rotating portion is at an angular orientation at which the inlet and outlet pair are coincident. More than one inlet may be paired with an outlet, and vice versa. Channels can be formed to allow the inlet and outlet pairs to be in fluid communication when they are not coincident. Inlets and outlets can also be radially spaced different distances from the axis of rotation such that fluid communication between these inlets and outlets are blocked at all angular orientations of the rotating portion.

Abstract: A distribution valve for directing high pressure coolant to various stations of a metalworking machine or similar device. A hollow shaft directs high pressure fluid to an aperture in a seal plate. The aperture is selectively coupled to one of several seals mounted in a housing. Each seal is formed with an axial passageway for directing fluid to its respective station when aligned with the aperture. A biasing means holds the seal against the seal plate to provide a leak free interface.

Abstract: A rotary ball valve assembly and method for forming utilizes a compression spring subjected to a non-torsional, axially directed compressive force to urge an annular seal into sealing engagement with a rotatable ball and, while so subjected, inwardly deforming a tubular member attached to the housing by an electromagnetic force to form an annular abutment retaining said compression spring.

Abstract: A metering device includes an inlet and outlet for a material (liquids, gases or solid particles) to be metered, a rotatable ball driven by a shaft and interposed between the inlet and outlet seats. The rotatable ball has a transverse bore containing a sealess shuttling member which can reciprocate back and forth along the bore between two sealing seats so as to seal against one or the other. The sealess shuttling member is propelled by pressurized material which flows into the bore without surface-to-surface contact of the shuttling member with the bore wall until is engages one of the two sealing seats. Each time the rotatable ball rotates 180.degree., a metered shot is ejected resulting in a quasi continuous flow depending upon a rotatable ball revolution rate.

Abstract: A small flow control valve with cartridge type seating arrangement is shown and described. A conventional valve housing with inlet and outlet ports and a seat ring cartridge. A plug with a lower throttling profile engages within the seat ring bore. A deformable seal is provided and is capable of being deformed by a metal collar radially inwardly to compress the exterior of the upper contoured plug portion to prevent leakage in the closed valve position. The collar is held in constant compression by a circular spring placed between the collar and a groove located within a bore of the cartridge. The valve further has an actuating device adjustably attached thereto.

Abstract: Imperviousness system composed of a metallic toric joint (9) compressed between two bearings (27, 28) which together form an acute angle (.alpha.) so as to produce a sliding and polishing of the skin of the joint and reduce the local levellings which would compromise the imperviousness capacity of the joint on each closing operation.

Abstract: A high pressure valve is disclosed having dual, independent seat to closure member seals, the dual seal arrangement including a primary seal and a second seal, each operating independently, in proper sequence, each acting in the same direction, and each being pressure actuated, with provision for sealing fluid.

Abstract: In a preferred ball-valve construction, a valve body has spaced inlet and outlet ports on an axis of flow that is controlled by an interposed ball; the ball is rotatable about a body-fixed axis which intersects the axis of flow at the geometric center of the ball. In the closed condition of the valve, an annular valve-seat member associated with one of the ports has circumferentially sealed contact with the ball. The annular valve-seat member is guided for axial displaceability into and out of its engageability with the ball, and actuation of the valve utilized coordination of valve-seat displacement with ball rotation such that valve-seat engagement with the ball is only for the closed condition of the valve, and such that, valve-opening rotation of the ball can occur only while the annular valve-seat member is in axial-clearance relation with the ball. Various embodiments are disclosed.

Abstract: The valve assembly 20 has two housing halves 22 which are bolted together to form a housing 24 for two resilient valve liners 26 with coaxial through passages 28 for the flow of fluids through the assembly. A metal gate 30 selectively blocks the through passages 28. Each valve liner 26 has a radially extending flange 32 in which is embedded a frustoconical metal spring 34 which biases the flanges against the gate 30 and retains a seal about the gate in a valve closed configuration. The assembly has a split seat formed by two seat inserts 36 retained in the housing halves 22 beneath the valve liners 26. The seat inserts 36 are open to the bottom of the housing 24 and permit debris to be ejected from the valve assembly 20. The spring may be formed to have ends which are not connected and positioned by inserting a locator tab on the exterior flange of the liner into a corresponding depression in the valve housing.

Abstract: A stop valve which is in particular constructed as a valve top for a sanitary fitting, contains an actuating member constructed as a rotary spindle. The actuating member, which is held in axially non-displaceable manner, engages with a hexagonal neck in a closing body, whose external thread engages in an internal thread of the valve top. The closing body has a closing face cooperating with a valve seat. The valve seat is displaceable to a limited extent in the axial direction and contains a rubber-elastic member.

Abstract: A cover assembly for a container includes: a cylinder base body with an axial bore therethrough, a lower portion for engaging an entry of the container, and an annular flange extending inwardly and radially into the axial bore; a shield mounted on an upper portion of the base body and having a central opening aligned with the axial bore of the base body; and a valve unit including a coil spring provided within the axial bore and placed on the annular flange, a hollow cylinder-shaped valve seat provided axially in the axial bore of the base body and inserted into the coil spring such that the valve seat can communicated with the container. The valve seat has an outwardly and radially extending press member which is biased by the coil spring toward the shield, and a blocking valve with a spherical external face and an axial hole extending therethrough.

Abstract: The metering device comprises a housing, defining at least one inlet for the material to be metered and at least one outlet for that material, and at least one rotatable ball driven by a shaft, the ball having a transverse bore containing a shuttling ball moving linearly in the bore between two seats and seals against the one or the other seat. The rotatable ball is captured between the seats and seals under pressure against the outlet seat. Such a metering device allows an exact metering, in shot or rapid shot resulting in near continuous flow form, has great simplicity of construction with few working parts such as that it may easily be placed at the dispensing end of a pressure transfer system for liquids and gases and acts as shut off valve between metering use such that it prevents stalled hydrostatic fluid pressure behind the metering device from causing a flow surge ahead of the metering device at start up.

Abstract: A seal for a gas isolator comprises a cantilever leaf spring (1) attached to a fixed frame or a movable member (2) of the isolator, and a bias spring (3) acting on the leaf spring, and a bar (4) disposed below the seal for clamping and supporting the latter, characterized by at least one additional damping element which will usually comprise a further leaf spring (7), and characterized in that the clamping/support bar (4) is of reduced width.

Abstract: A high pressure valve is disclosed having dual, independent seat to closure member seals, the dual seal arrangement including a primary seal and a secondary seal, each operating independently, in proper sequence, each acting in the same direction, and each being pressure actuated, with provision for relieving excess fluid pressure.

Abstract: A valve body including a first body member and a second body member adjacent the first body member, with the first and second body members defining a through-passage. A ball valve element having a bore therethrough is disposed within the valve body. A ball seat is interposed between the first and second body members. The ball seat is positioned to sealingly engage the ball valve element when the ball valve element is in the closed position to prevent fluid from passing by the ball valve element. The ball seat is resiliently biased against the first body member and against the ball valve element by a single biasing member positioned to provide both a fluid seal and a resilient bias between the ball seat and the first body member.

Abstract: An apparatus for sealing shut-off devices located in gas or liquid transporting pipelines having a sealing arrangement, which seals the shut-off device against a casing, the sealing arrangement having a gasket engageable against the circumferential surface of the shut-off device, a seating ring supporting the gasket, two chambers which can be supplied in a controlled manner with a pressure medium, and a method by which the gasket can be raised from the circumferential surface and pressed against the circumferential surface. The sealing arrangement has a driving member positively connected to the seating ring and a displaceable intermediate piston located on the driving member. The first chamber is located between the driving member and the intermediate piston and when subject to the action of the controlled pressure, brings about a movement of the driving member in the gasket raising direction.

Abstract: A high pressure ball valve is disclosed having dual, independent seat to ball seals, the dual seal arrangement including a primary seal and a secondary seal, each operating independently, in proper sequence, each acting in the same direction, and each being pressure actuated, with provision for relieving excess fluid pressure.

Abstract: A dynamic seal is provided between a rotatable ball control member and a noise attenuator in a fluid control valve. In one embodiment a noise attenuator is rigidly clamped in the valve body and a floating, spring biased seal is provided in the attenuator and facing the ball. A bi-directional fluid control valve is provided with two rigidly mounted noise attenuators each having a floating, spring biased ball seal. In a second embodiment a noise attenuator is floating, spring biased towards the ball and includes an annular seal retained in the attenuator. Pressure balancing the fluid flow pressure and the spring bias enables substantially zero seal engagement with the ball during ball rotation, while enabling a reliable seal of the ball in the shut-off valve position.

Abstract: A floating gate valve seat has an integral static seal comprising a convex arcuate limb 9 and a projecting tip 25 on the limb arranged to contact a seat pocket surface 12 and place the limb in flexing stress to effect a seal at the tip 25. A set-back stop surface 15 on the valve seat limits the compression of the seal and the axial movement and the valve seat 7.

Abstract: A gate valve [10] is disclosed having a primary [300, 302] and secondary [316] seal on the upstream and downstream sides of the gate [15], wherein the gate [15] forms a seal with the seat [300] which is activated mechanically [320] and is fluid powered, and wherein a resilient seal [316a] is moved toward the gate [15] by mechanical actuation [31 ] to form a fluid powered secondary fluid-tight seal with the gate [15].

Abstract: The valve assembly 20 has two housing halves 22 which are bolted together to form a housing 24 for two resilient valve liners 26 with coaxial through passages 28 for the flow of fluids through the assembly. A metal gate 30 travels vertically within the housing 24 to selectively block the through passages 28. Each valve liner 26 has a radially extending flange 32 in which is embedded a frustoconical metal spring 34 which biases the flanges against the gate 30 and retains a seal about the gate in a valve closed configuration. The assembly has a split seat formed by two seat inserts 36 retained in the housing halves 22 beneath the valve liners 26. The seat inserts 36 are open to the bottom of the housing 24 and permit debris to be ejected from the valve assembly 20. An alternative embodiment valve assembly has a wave spring which applies a force through an embedded ring to bias the valve liners against the gate.