Abstract: A pressure relief valve which has a body including first and second openings for connection in a line and an interior wall defining a flow-through passageway extending from the first opening to the second opening. The body further includes a chamber having an inlet port and an outlet, the inlet port providing fluid communication between the chamber and the passageway. A guide is removably secured to the body and defines a bore extending into the chamber and an open-ended portion extending away from the chamber. A spindle is slidably disposed in the bore between a first position in which the port is open and a second position in which the disc seats in and closes the port. In the second position, the face of the disc exposed to the fluid in the passageway is recessed from the internal wall a distance no greater than one half the diameter of the passageway. A retention nut is threadingly secured to a portion of the spindle extending into the open-ended portion of the guide.

Abstract: A pressure-limiting valve has a closure member (5) which, in its closed position, rests with initial stress against a valve seat (4) and has, on the side towards the valve seat (4), a shoulder (6) which can be formed by a circumferential flange (7) on the closure member (5). This induces enlargement of the opening stroke upon a slight opening of the closure member (5) as the flow strikes against the shoulder (6).

Abstract: The present invention discloses a fluid relief device for relieving pressure of a fluid stored in a container or tank, or fluid used in a piece of equipment. In one aspect such a device has a body member with a primary channel therethrough in communication with a container of a contained fluid under pressure. When the pressure of the contained fluid under pressure exceeds a predetermined level, the pressure of the contained fluid moves a cover which is sealingly in place to close off the primary channel. During normal conditions the force of the contained fluid is insufficient to move the cover and leakage of the contained fluid past the cover is inhibited by the provision of a barrier fluid supplied into a barrier fluid chamber to oppose the contained fluid, the barrier fluid at a pressure greater than the normal pressure of the contained fluid.

Abstract: A combination pressure-vacuum relief valve assembly is provided for mounting in a port of a container. A two-part, generally hollow valve housing defines a valve chamber and includes a housing body part adapted for mounting in the port and which has an inlet communicating with the container. A housing cap part is secured to the body part and defines an outlet therebetween. A pressure valve seat is formed on the housing body part surrounding the inlet. A two-part, generally hollow pressure valve is movably mounted within the valve chamber and includes a valve body part for engaging the pressure valve seat. The valve body part includes a first vacuum relief passage communicating with the container through the inlet. A valve cap part is secured to the valve body part and includes a second vacuum relief passage communicating with atmosphere through the outlet.

Abstract: A breathing regulator for use in underwater breathing comprising a diaphragm and poppet actuated upon user demand. The poppet including at least one baffle located intermediate its ends wherein when air is demanded by a user of the regulator air travels through the valve and continuously impinges upon the baffle and reduces the effort of the user required to operate the valve. The regulator further comprises a sleeve which is concentric about the air passage chamber which facilitates more efficient air delivery to the user. The sleeve is selectively controlled by the user either to enhance the venturi flow of air or to cancel the venturi effect, dependent upon the needs of the user.

Abstract: To measure flow rates, the cross-sectional shape of the flow path is changed by inserting a multiple position gate into the flow path and altering the position of the gate to maintain the head of liquid constant with a reduced flow cross section. The position of the multiple position gate is correlated with the depth as measured with a bubbler to provide an indication of flow rate. To purge the bubbler line, a purge tank is located near the bubbler line. At timed periods or as manually initiated the controller causes an increase in pressure in accumulator portion of the purge tank. When a predetermined pressure is reached, a purge valve in the purge tank opens, rapidly allowing a burst of air at a substantial pressure and velocity to flow through the bubbler line to remove any material adhering to the bubbler outlet port.

Abstract: A safety valve for releasing excessive fluid pressure from a pressure vessel including a valve body having an inlet and an outlet, a seat bushing connected into the inlet defining an inlet flow passage, a valve seat on the inward end of the seat bushing, a valve disc having a seat thereon movably mounted in the valve body for opening and closing the valve, a spring coupled with the valve disc for biasing the valve disc toward a closed position. The valve disc includes a convex end portion to reduce turbulence during flow into the valve to permit improved seating of the valve disc and an external annular recess defining an annular lip on the valve disc including a seat having a frustoconical seat surface, the lip being flexible to improve the disc seat contact with the seat around the valve inlet to increase the seat tightness of the valve.

Abstract: A fluid pressure relief system and method for a pressure vessel or tank (10) having a normal vent (16) with a first pilot operated safety valve (18) and an emergency vent (62) having a second pilot operated safety valve (25). A vapor recovery line (20) is connected to relief valve (18) and collected at a vapor storage container (21). A manway (22) on the pressure vessel (10) shown in FIG. 2 defines the emergency vent (62) and a main valve member (66) has a counterweight (74) thereon to urge main valve member (66) to a seated closed position on nozzle (60). The first pilot operated safety valve (18) for the normal vent (16) is shown in FIG. 7 and has a T-shaped body (142) with a main relief valve member (172) at one end of the body (142) mounted for movement in a generally horizontal direction and controlled by a diaphragm (176) at an opposite end of the body (142).

Abstract: A pressure relief valve in a cap, and more particularly a pressure relief valve in a cap for use with pressure vessels in chromatography systems. In one exemplary application the valve is contained within the cap of a pressure chromatography column. In a second exemplary application the valve is contained within the cap of a mobile phase reservoir of a high performance liquid chromatography system. The valve generally comprises a body, a sealing element, and a force applying means. The body of the valve is formed into the cap and defines an inlet in communication with the interior of the column, an outlet in communication with ambient air, a first bore, and a seat. The sealing element slides within the body and is urged into sealing contact with the seat by the force applying means. The sealing element has a raised lip at its sealing face to provide a substantial sealing force per unit of sealing surface area.

Abstract: A check valve (4) with spherical, spring-loaded valve head (25) is used for pulsating flows, especially in a fuel injection system for Otto engines. As a result of low flow resistance, such check valves have had a tendency to cause noise when the valve head (25) strikes down against the valve seat (11) during pulsating of the flow caused by selective opening of the fuel injection nozzles. The valve head (25) is designed with a flange (7) downstream of the valve seat (11), and this flange (7) interacts with a narrow boring (13) during the first part of the opening stroke. Consequently, a secondary throttling (12) is formed, in addition to the primary throttling between the valve head (25) and the valve seat (11), which contributes to the valve head being forced away at a distance from the valve seat.

Abstract: A safety valve for preventing overpressure in plants operating with gaseous and/or vaporous and/or liquid fluids and/or mixtures includes a valve body with a valve seat and a valve member which controls the valve seat and includes a seat valve and a valve piston securely fixed to the seat valve at a distance thereto.

Abstract: A pressure relief vent for a pressure vessel such as an over the road tank trailer including a poppet forced into sealing engagement with a valve seat by a compression spring which maintains the poppet in sealing engagement with the valve seat to a set pressure and which poppet upon the occurrence of pressurized fluid in the trailer tank sufficiently in excess of the set pressure lifts the poppet up off of the valve seat a distance sufficient to permit the over-pressurized fluid to flow out of the vent at the flow rate, the outer peripheral portion of the poppet is provided with outwardly curved and downwardly extending portions which form the escaping over-pressurized fluid into a jet stream which provides reaction force which assists the pressurized fluid in maintaining the poppet lifted off of the valve seat to provide the flow rate and which permits the use of a stiffer and therefore shorter compression spring enabling the pressure relief vent to be shorter in height while maintaining the required flow ra

Abstract: An in-line check valve includes a housing defining a cavity with an inlet and an outlet, a removable seat attachable to the inlet, a piston movably positioned in the housing and including a seal that operably engages the seat, and a spring positioned around the piston for biasing the piston into engagement with the seat. The piston defines a surface impinged on by fluid flowing therethrough so that the differential pressure across the valve in a given flow range is less than the opening pressure. The housing defines a plurality of lugs which retain the piston within the housing and permit servicing of the seal.

Abstract: A safety valve including a brass valve body having a through bore provided with a circular sharp-edged valve seat and another sharp edge. A valve stem carrying a ball valve and a biasing spring disposed in the through bore. A cap member screwed through onto the brass valve body and causing the ball valve to be seated on the sharp-edged valve seat and causing the ball valve to be positioned in close proximity to the other sharp edge. A plurality of radially vent holes formed in the brass valve body for venting fluid pressure to atmosphere when the ball valve becomes unseated from the sharp-edged valve seat. A lock nut for locking the cap member in position and a spring pin carried by the valve stem to permit the ball valve to be manually opened.

Abstract: The spill valve includes an annular seat surrounding a circular port in the top of a tank containing liquid under pressure and a circular poppet valve member movable between open and closed positions relative to the seat. A plate overlies the valve member and extends laterally therebeyond and is integral around its periphery with a depending skirt which overlaps the seat around its perimeter and is spaced a slight lateral clearance distance therefrom for cooperation therewith and with the valve member to define an annular chamber when the valve is closed, the extension plate effectively increasing the valve member area against which the internal tank pressure is exerted when the valve member moves from its closed position. The valve is biased closed by a plurality of free weights which sit atop the extension plate.

Abstract: A pressure release valve which includes a body having a cavity in the form of a frustum extending from a circular base and terminating in a circular opening at the top of the frustum. An annular lip extends perpendicularly from the circular opening toward the base of the body, the lip having a recessed annular shoulder. A central shaft extends axially through the circular opening in the body. A spindle head disc extends radially from the central shaft and has a circular edge seatable in the recessed annular shoulder. A top disc extends radially from the shaft, the top disc terminating in a downwardly extending flange spaced from the spindle head disc circular edge and spaced from the annular lip. Seals between the spindle head disc and the top disc provide a seal with the annular lip when the valve is in the closed position.

Abstract: A pressure relief valve (14, 14A) has a reciprocable valve member (34, 34A) for seating on an annular seat face (66,66A) of a nozzle assembly (38,38A). The nozzle assembly (38,38A) has an inner seat ring (40,40A), a radially outer anchor ring (42,42A), and a flexible connecting member (44,44A) extending in a generally radial direction between the outer peripheral surface (64) of the seat ring (40,40A) and the inner peripheral surface of the anchor ring (42,42A). Upon seating or reseating of the valve member, (34,34A), seal face (36,36A) contacts the seat face (66,66A) of seat ring (40,40A) and flexible connecting member (44,44A) flexes upon relative movement of the seat ring (40,40A) after initial contact of the valve member (34,34A) against the seating ring (40,40A) thereby to act as a shock absorber for absorbing impact forces.

Abstract: A self acting pressure air pulse control valve for use with fluidizing and pneumatic conveying systems for dry particulate material comprises a housing having a chamber in which a plate type closure member and an actuating piston are disposed and interconnected by an elongated actuating rod. A spring engages the actuating rod through a pivotally supported lever and biases the closure member toward a closed position. Pressure air acts across the face of the closure member to allow the valve to crack open whereupon pressure air acting on the larger actuating piston face snaps the valve to the fully open and unrestricted flow position. A reduction in pressure of the air flowing through the valve allows the biasing spring to reclose the valve to repeat its operating cycle.

Abstract: A flow control device illustrated as a pressure relief valve (10, 10A) has a reciprocable valve member (22, 22A) for seating on a face (20, 20A) of a fixed seat ring (18, 18A). The valve member (22, 22A) includes a hub (36, 36A), an outer seal ring (38, 38A), and a flexible connecting member (40, 40A) extending between and connecting the seal ring (38, 38A) and the hub (36, 36A). Upon seating or reseating of valve member (22, 22A) seal ring (38, 38A) contacts fixed seat ring (18, 18A) and flexible connecting member (40, 40A) flexes upon relative movement of the hub (36, 36A) after initial contact of the seal ring (38, 38A) with the fixed seat ring (20, 20A) to act as a shock absorber for absorbing impact forces.

Abstract: A fluid control valve having a discharge port controlled by an obturator is characterised by the discharge port being shaped to cause a marked drop in back pressure at a small critical opening distance of the obturator from the port, thereby to provide impetus to initiating discharge. The discharge port has effectively a concave surrounding surface for this purpose. To achieve good sealing with light loading, the port preferably also has a convex surface immediately surrounding its orifice. The preferred configuration is a convex surface bounded by a wall. The obturator may be resiliently loaded to enable its response to dynamic effects of fluid flow to enhance opening "lift". The obturator may be, e.g. a lever, a diaphragm or the armature of a solenoid.

Abstract: In a check valve or stop/check valve comprising a housing having an inlet port, an outlet port and a valve seat between the two ports, a valve disc moves axially within a valve housing between open and closed positions, so that fluid flow applies pressure against the valve disc to automatically open the valve, but when the fluid stops or reverses, the valve automatically closes to prevent backwash. Under conditions of pulsating, low-volume fluid flow, a ridge on the valve seat and a deflector ring on the valve disc deflects the flow of fluid, thereby using the velocity of fluid to increase pressure against the valve disc so as to smoothly and gently move the valve disc, reduce vibration of the valve disc and prevent it from striking the valve seat.

Abstract: An adjustable pressure relief valve is disclosed comprising a valve body having an inlet and an outlet, a spherical valve seat associated with the inlet, a valve member having a mating spherical sealing surface configured to seal off the flow of fluids through the valve at the valve seat, a huddling chamber around the periphery of the mating spherical sealing surface, an adjustment screw supported in the valve body to allow rotational but not longitudinal movement of the adjustment screw with respect to the valve body, a compression member connected to the adjustment screw and mounted within the valve body which moves longitudinally with respect to the adjustment screw when the adjustment screw is rotated and a resilient member biased between the compression member and the valve member. In the preferred embodiment, the mating spherical sealing surface is provided by staking a spherical ball inside a cavity in the valve member, leaving portion of the ball exposed.

Abstract: An inflatable penile implant includes a novel compensator which both absorbs any increased pressure to protect the components of the hydraulic system from pressure damage and which permits the implant to be shortened in length without impairing its function. An improved tapered pumping chamber, improved pump valve and an improved pressure relief valve are also disclosed.

Abstract: A snap-action permanently indicating pressure relief valve is disclosed. The valve includes a valve member defining a flow path having an area less than the area of an inlet wherein the inlet pressure initially acts over a portion of a pressure surface of the valve member equal to the inlet area and subsequently acts over the entire area of the pressure surface to suddenly increase the velocity of the valve member. The valve member smacks and permanently deforms a deformable over pressure indicating element to give permanent indication of an over pressure condition.

Abstract: In a pneumatic ram boring machine for laying pipelines without trenching, which is connected to a source of compressed air by a hose, a valve that suddenly opens automatically at a predetermined pressure is arranged upstream of the striker piston. On opening the valve a pressure wave results which reaches the impact piston almost undamped and prevents it from stopping at a dead center position and not starting.

Abstract: Two pressure control valves have most components in common. One valve is a direct-acting sequence valve and the other a vented counterbalance valve with pilot assist. Both valves have a set opening pressure which is insensitive to secondary port pressure. Both valves may provide free reverse flow. The valves include a spring force reduction chamber which receives hydraulic fluid at primary port pressure. Part of the opening force exerted at the primary port is offset by pressure in the spring force reduction chamber so that a spring having a smaller spring constant may be used to resist opening force. This offsetting force may be readily modified by changing the diameter of the piston shaft of the valve.

Abstract: An inhalation/exhalation valve for use in conjunction with a medical respiration apparatus to maintain an adjustable positive end expiration pressure through incorporation of novel valving elements including a novel, adjustable spring for establishing and maintaining the threshhold pressure of exhalation and a novel flow control valve disk structure which utilizes the dynamic pressure of exhalation flow to assist in providing control over and fine adjustability of the valve disk motion and which further permits continuous supply flow during both the inhalation and exhalation portions of the patient's breathing cycle.

Abstract: An adjustable pressure relief valve is disclosed comprising a valve body having an inlet and an outlet, a valve seat associated with the inlet, a valve member configured to seal off the flow of fluids through the valve at the valve seat, an adjustment screw supported in the valve body to allow rotational but not longitudinal movement of the adjustment screw with respect to the valve body, a compression member connected to the adjustment screw and mounted within the valve body which moves longitudinally with respect to the adjustment screw when the adjustment screw is rotated and a resilient member biased between the compression member and the valve member. In the preferred embodiments, a connection between the adjustment screw and the valve member aligns the valve member with the valve seat. Also, the adjustment screw provides an unchanging stop surface to limit the lift of the valve seat as well as inside diameter guiding to prevent buckling of a helical spring used as the resilient member.

Abstract: A pulse-irrigation system comprises a pressurized water supply line supplying water in a continuous, non-interrupted manner, a water irrigation device, and a pulsating device for converting the pressurized water of the line to the pulsating output when supplied to the irrigation device. The pulsator device comprises an inlet orifice of restricted cross-sectional area, an outlet orifice of substantially larger cross-sectional area, and a valve which is normally closed, automatically opens at a predetermined opening pressure lower than that of the inlet pressure to connect its inlet to its outlet, and automatically closes at a predetermined closing pressure lower than its opening pressure. The pulsator device further includes a reservoir for the fluid and located between the inlet orifice and the valve such that when the valve is closed the reservoir fills up and at the same time builds up pressure until the valve opens to discharge the fluid within the reservoir.

Abstract: In a spring-loaded safety valve for gas and vapor, a valve disk which faces a valve seat and is movable to open or close the valve is provided with a deflecting collar which includes at an inner face thereof overlapping the valve seat two cone portions smoothly connected to each other by radii.

Abstract: A direct-acting, differential piston relief valve has a spring chamber pressurized with fluid from a passage through the piston. The fluid within the chamber is at the same pressure as that at the inlet valve and provides a valve closing pressure against the inner face of the piston. The piston face at the inlet valve has an annular extension. The inner circumference of this extension meets the spherical valve seat when the valve is closed. The diameter of the inner face of the piston is smaller than the diameter of the piston face annular extension. Inlet pressure working on this area difference produces the hydraulic force which is opposed by the spring. No piston face area is exposed to forces tending to close the valve due to Bernoulli effects when the valve begins to open. The spring within the spring chamber has spring guides at each end which contain a ball. The ball transmits the spring force to the piston on one end and a sealed closure at the other end.

Abstract: A fluid flow controller utilizes a vacuum assist to decrease accummulation. The controller comprises a poppet and a poppet seat between the fluid inlet and the fluid outlet. An axially movable piston is connected to the poppet so that the piston and poppet move axially together. A high pressure chamber is at the pressure of the inlet fluid and a low pressure chamber is in fluid communication with the gap between the poppet and poppet seat. The difference in pressure between the two chambers is used to bias the poppet away from the poppet seat.

Abstract: A flexible beam arrangement functioning as a valve member guide in a pressure relief valve for maintaining proper alignment of a valve member and a valve seat is disclosed wherein one end of the flexible beam is affixed to a valve housing and the other end thereof is fixed to the valve member so that opening and closing of the valve is associated with a flexing of the beam, however sliding motion of the valve member relative to the guide is eliminated. This assures an accurate reseating of the valve member on the valve seat. In the preferred form the flexible beam is formed as a relatively flat disc with an outer peripheral portion being the one end that is fastened to the housing and a central portion being the other end which is fastened to the valve member. Fastening of the other end to the valve member may be accomplished by a shoulder and snap ring arrangement so that the valve member may rotate about its axis relative to the disc, however, axial valve movement requires flexing of the disc.

Abstract: A valve head of the pressure relief valve is urged into the closed (seated) position by a spring, assisted by a force derived from pressurized fluid which is situated in a chamber behind the valve head and which is admitted thereto from the upstream side of the valve seat through a chamber in the valve head. The chamber in the valve head is open toward the inlet port of the valve and is partly defined and surrounded by a skirt-like extension oriented transversely to the axis of the valve inlet port. The diameter of the chamber whose opening has a plane generally perpendicular to the direction of valve head motion, is at least as large as the diameter of the valve intake port. In the seated (closed) state the skirt-like extension reaches transversely into the inlet port at least as far as the axis of the inlet port and in the maximum open position the skirt-like extension is at the most just clear of the inlet port.

Abstract: A miniaturized check valve comprises a generally tubular body including a cylindrical base and a guide sleeve of reduced diameter which axially extends from the base. The body forms a an interior valve seat which surrounds an axially extending fluid passageway. The guide sleeve has a plurality of angularly spaced discharge openings and a pair of pilot orifices which are axially spaced from the valve seat. A valve ball is displaced from the valve seat to form a fluid flow path which extends generally axially through the valve seat and into the guide sleeve and thereafter generally radially through the orifices and openings for flow exteriorly of the guide sleeve. The ball is biased by a spring assembly which comprises a pair of axially aligned springs having a relatively low pre-load force and low spring rate.

Abstract: A quick-action on/off valve comprises a housing including a partition having an interconnecting passageway between the two chambers on opposite sides of the partition. One chamber includes a fixed piston and a movable cylinder, the cylinder including a resilient disc between its closed end and the port leading from the first chamber, and a spring urging the cylinder in the direction tending to close the latter port. Spacing means are provided between the partition and the open end of the cylinder for continuously maintaining communication between the first chamber and the interconnecting passageway. The difference in the cross-sectional areas of the first port and of the cylinder result in a smaller area of the cylinder being effective to open the valve when the valve is closed, but a larger area of the cylinder being effective to close the valve when the valve is open, thereby providing a quick-action opening and closing of the valve.

Abstract: A pressure relief device (28) removably secured to a pressure vessel (10) has a valve closure (83) including an inner valve plate (84) and an outer cover (96) thereover. A spindle (68) is secured separately to valve plate (84) and cover (96), and springs (80, 82) positioned below a tapered plug (54) urges valve closure (83) to a closed position. An elastomeric O-ring (108) between plate (84) and cover (96) forms the primary seal and may be removed and replaced while valve plate (84) remains in a seated closed position.

Abstract: A differential fluid pressure indicator including a bypass valve which provides an indication that the filter is in the bypass condition. The bypass valve includes a differential area piston which includes at the outlet port thereof a restriction orifice adapted to insure a predetermined stroke of the poppet in the bypass valve, thereby to insure actuation of the indicator.

Abstract: In a poppet-type relief valve, including a housing having a spring guide assembly axially biasing a valve toward a seat in its inlet passageway, a soft valve seat member is coaxially disposed in the inlet passageway. The soft seat member includes a rigid surface limiting movement of the spring urged valve toward the inlet passageway and further includes a resilient ring seal positioned adjacent the rigid surface in a manner to be cushion contacted by and form a bubble tight seal with the spring urged valve before the valve contacts the rigid surface.

Abstract: A poppet-type check valve utilizing an integral detachable flow control assembly for insertion into a cooperating housing. The checking poppet is oriented with its actuating stem, concentric guide, and concentric force bias spring downstream of the check flow controlled orifice. In a preferred embodiment, the flow control assembly is located internal of a housing having a first flow length adjacent the controlled flow orifice and seat, and a second converging flow length abutting said first flow length, and a terminating flow outlet adjacent the valve outlet port. When mounted internal of the preferred housing, the valve poppet assembly lies partially within the first flow area and extends a predetermined distance into the converging section, thereby greatly reducing turbulence and having a demonstrated reduction in medium flow pressure drop over presently used units.

Abstract: A normally-open, solenoid-controlled valve includes a stationary valve-seat spindle and a cylindrical valve sleeve encircling and slideable along part of the valve-seat spindle. The valve-seat spindle has an annular control edge and the valve sleeve includes a pressure-responsive surface which is reciprocably moved into and out of valve-closing contact with the control edge. The valve-seat spindle includes a flow passage therein extending to and discharging into a plenum region formed radially inward of the control edge between the spindle and the sleeve. The pressure-responsive surface of the valve sleeve is a substantially continuous frustrum of a cone whose apex extends in the direction of the valve opening and which extends radially outward from a sleeve inner diameter A to an outer diameter C (point C) of discontinuity in that surface.

Abstract: The present invention comprises a valve body (24) with an inlet (28) and an outlet (30), and an inlet-closing poppet (32) moveably disposed within a chamber (26) in the valve body, the poppet incorporating a piston head (34) whose face (36) opposes the inlet and from which projects a plug (62) for closing-off the inlet (28) from the remainder of the piston face (36) when the poppet is at its inlet-closing position. A spring (54) urges the poppet towards its inlet-closing position with sufficient force to keep the inlet closed until the fluid reaches a preselected cracking pressure, whereupon the spring allows the poppet to be displaced slightly, exposing the remainder of the piston face to the fluid. The action of the fluid on the piston face is then sufficient to drive the poppet fully back to an annular stop (60) provided within the valve body whose engagement also serves as a partial seal about the periphery (70) of the piston.

Abstract: An integrated valve unit for a pressure control circuit which comprises a case, a drier wholely contained in the case, and a check valve formed and positioned in an inlet of the case having a longitudinal axis perpendicular to the longitudinal axis of the case. The check valve includes a cylinder chamber formed in the case having two end faces and a side wall, a fluid inlet port formed in one of the end faces, a pair of discharge ports in the side wall longitudinally spaced from each other and opening into the case, an axially slidable piston inserted into the chamber, a biasing member urging the piston towards one end face having the fluid inlet port formed therein, and an elastic seal member fixed to the piston member. The piston is capable of selectably closing the discharge ports upon axial sliding thereof. The elastic seal member is capable of sealing the portion of one end face including the fluid inlet port as the piston member slides toward that one end face.

Abstract: A pressure/vacuum valve assembly for a fuel tank filler neck comprises a pressure-release valve member, a vacuum-relief valve, and a pressure-release control member in a vent passageway. The vent passageway has an axially outwardly facing surface and a radially inwardly facing surface. A yieldable control spring urges the pressure-release valve member normally to close and seal the vent passageway. The pressure-release control member has an axially inwardly facing surface which forms a first restricted opening for the flow of fuel vapors. The control member has a radially outwardly facing surface which forms a second restricted opening with the radially inwardly facing surface of the vent passageway. The pressure-release valve member is urged in opposition to the control spring to open the vent passageway in response to a predetermined superatmospheric pressure and allow fuel vapor to flow in the first and second restricted openings.

Abstract: In a distributor type fuel injection pump for use with an internal combustion engine, which is equipped with an injection timing control device operable in response to oil pressure within a pressure oil chamber, which is variable as a function of the rotational speed of the engine, an overflow valve is provided, which is closed at the start of the engine when the oil pressure within the pressure oil chamber is low, and is opened during subsequent operation of the engine to cause escape of the above oil pressure to a lower pressure zone in the pump, to thereby cause the above injection timing control device to obtain an advance in the fuel injection timing.

Abstract: A reversing valve for a combination meter, including a closure element, movable in the axial direction, which is provided with a cylindrical closure ring which in the closed position of the reversing valve covers radially outwardly directed valve openings, and having at least one channel extending essentially axially associated therewith, which channel is closed in the closed position though already after slight shifting of the closure element in the direction of its open position communicates the working chamber of a hydraulic adjustment member with the main flow. The working chamber additionally has a presettable opening which is always open in the direction of the auxiliary flow or total flow. The effective-pressure-cross section of the closure element is suddenly enlarged inwardly during opening, and is reduced in a sudden manner during closing, by having the main flow act on the working chamber.

Abstract: A circulating valve is provided for connection into the tubing string of a well for establishing selective flow of fluid between the tubing string and the well casing. The circulating valve incorporates a valve body which is adapted for connection into the tubing string of the well, which body defines a flow passage in registry with the flow passage of the tubing string. A valve seat is provided on the valve body and an outlet opening is defined downstream of the valve seat which is of sufficiently restricted dimension to permit opening of the valve at a particular injection pressure and to permit maintenance of the valve open condition by means of a pressure lower than the valve opening injection pressure.

Abstract: In a poppet-type relief valve, including a housing having a spring guide assembly axially biasing a valve toward a seat in its inlet passageway, a soft valve seat member is coaxially disposed in the inlet passageway. The soft seat member includes a rigid surface limiting movement of the spring urged valve toward the inlet passageway and further includes a resilient ring seal positioned adjacent the rigid surface in a manner to be cushion contacted by and form a bubble tight seal with the spring urged valve before the valve contacts the suface.

Abstract: A relief valve with a low hysteresis closing curve with a fixed seat and a spring-biased poppet which is guided for longitudinal movement by an axial guide sleeve and aligns with its seat by pivoting about a fixed point through a small angle of rotation.

Abstract: The leak detection system includes a leak detection sensor for sensing the pressure of fluid product in a supply line and holding the flow rate of the fluid through the supply line to a value below a maximum when the sensed pressure is below a predetermined value. The sensor is connected to the supply line in proximity to a pump. A pressure responsive valve is connected in the supply line between the sensor and a dispensing nozzle for sensing pressure and stopping the flow of fluid product through the line when the pressure is below a minimum value. The pressure responsive valve allows the line pressure to build to a value sufficient to allow the sensor to complete its sensing cycle and permit full fluid flow.