Abstract: A pressure relief valve for relieving excess pressure in a fluid distribution system comprising a valve body having an inlet port and an outlet port in communication with an interior of the valve body. The inlet port is connectable to the fluid distribution system. A valve member within the interior of the valve body is movable between a closed position to prevent fluid flow through the body and an open position to permit fluid flow. The valve member is exposed to a first opening force exerted directly by the pressure in the fluid distribution system. There is a movable piston/diaphragm member co-operating with the valve member such that the piston/diaphragm is exposed to the pressure in the fluid distribution system to provide a second opening force for the valve member. A biasing system exerts a default closing force to move the valve member to the closed position. The closing force is set to be equivalent to a pre-selected pressure in the fluid distribution system.

Abstract: A pressure responsive oil flow regulating supply valve assembly includes an oil supply input; an oil supply output; an oil flow path defined between the input and output. A valving mechanism located in the oil flow path includes a device for restricting oil flow at a first level in response to normal pressure and for restricting oil flow at a second level in response to high pressure conditions. In addition, other levels of restriction may be provided for other pressure conditions.

Abstract: A flow control valve is disclosed wherein a housing defines a flow chamber with an inlet and an outlet. Disposed within the flow chamber is a telescoping poppet comprising an inner poppet and an outer poppet. A first spring is selected to bias the outer poppet to seal closed the inlet below a predetermined fluid flow rate. Above the fluid flow rate, the force of the fluid against the outer poppet compresses the spring, breaking the seal and allowing fluid to flow into the fluid flow chamber. Inside the outer poppet is an inner poppet which telescopes from the outer poppet. A second spring biases the inner poppet predominantly within the outer poppet, but an increased pressure in the outer poppet collapses the second spring and extends the inner poppet in a fully extended position. Fully extended the inner poppet seals shut the outlet of the fluid chamber. In operation, the first spring shuts the valve below a predetermined flow rate guaranteeing zero flow until a minimum flow rate is present.

Abstract: A system for controlling with safety the transfer or control of high pressure fluids from a container for use as to an inflatable escape slide. The pressurized container houses valve mechanisms such as a first and second valve mechanism, with the first valve mechanism controlling by actuation the on off flow of high pressure fluids to the second valve mechanism. The second valve mechanism controls the rate of flow by reducing the pressure for delivery to the inflatable escape slide. A safety valve operates in conjunction with the first valve mechanism and upon breaking of the valve mechanisms from the pressurized container to prevent the contents of the pressurized container from rapid escape or uncontrolled release.

Abstract: A system for controlling with safety the transfer or control of high pressure fluids from a container for use as to an inflatable escape slide. The pressurized container houses valve mechanisms such as a first and second valve mechanism, with the first valve mechanism controlling by actuation the on off flow of high pressure fluids to the second valve mechanism. The second valve mechanism controls the rate of flow by reducing the pressure for delivery to the inflatable escape slide. A safety valve operates in conjunction with the first valve mechanism and upon breaking of the valve mechanisms from the pressurized container to prevent the contents of the pressurized container from rapid escape or uncontrolled release.

Abstract: A mud saver valve is described that features an outer housing that retains upper and lower valve pistons therewithin. The pistons coordinate to provide a check valve so that fluid, such as drilling mud, is permitted to flow in one direction while under pump pressure and works as a relief valve in the event of excessive wellbore pressure when the pump is turned off. Both pistons are provided with apertured plates that selectively define fluid passages through the valve. In the described embodiment, the valve also includes a frangible vent cap that is self-securing and easily replaceable. The cap permits venting of excessive downhole pressures.

Abstract: A pressure compensating valve is configured as a pressure control valve for a fuel tank. The valve body is operatively connected to a membrane via a two-arm valve lever so that, when there is an underpressure in a control chamber, which is bounded by the membrane, the membrane is displaced in the direction toward the lever. The lever is then pivoted and opens the valve for pressure compensating the fuel tank by allowing air to flow in.

Abstract: A diaphragm/spring operated pressure relief valve having a sensing passage of substantially the same flow area as the outlet orifice of the valve whereby failure of either diaphragm results in “fail open” configuration with the addition of a sensing inlet shroud located to capture the total pressure at the inlet and channel it to the sensing chamber to allow the valve to relieve full rated capacity in the event the sensing diaphragm is ruptured.

Abstract: A pilot operated pressure valve which limits the rate of pressure rise and substantially eliminates excessive system pressure spikes, the valve including an inlet, a hollow cylindrical main body sealingly connected at one end thereof to the inlet, a pilot chamber having a sleeve slidably mounted within the main body and an operating pressure adjustment connected to another end of the main body adjacent another end of the pilot chamber for varying the operating pressure of the valve. A main chamber receives pressurized fluid metered through a main orifice and discharges pressurized fluid through a damping orifice when the main chamber is filled and fluid inlet pressure exceeds a preselected inlet pressure level sufficient to open a spring biased pilot ball downstream of the damping orifice. The inlet will open an exit port upstream of the main orifice for discharging pressurized fluid from the valve back to a supply tank when inlet pressure exceeds the operating pressure.

Abstract: A piston valve wherein a hollow piston type sleeve has a closed lower end surmounted by a sleeve which has a cylindrical outer surface which slides, and seals against a blank inner cylindrical surface portion of an outer body. Ports in the sleeve are moved into an open position of the valve as they traverse from the bank inner cylindrical surface portion towards the port of the outer body.

Abstract: An exhaust restriction device for an internal combustion engine is disclosed. The exhaust restriction device includes a main valve and a bypass valve for restricting the flow of exhaust gas. The main valve is located in a main passage and may be selectively closed. The bypass valve is located in a bypass passage and is biased into a position closing a port connecting the main passage and the bypass passage. Closing the main valve may cause exhaust back pressure to build against the bypass valve and an actuator therefor until the biasing force is overcome. When the biasing force is surpassed by the exhaust back pressure, the bypass valve opens to relieve the back pressure. The bypass valve closes when back pressure falls below the biasing force. A method of operating the exhaust restriction device is also disclosed.

Abstract: In accordance with the present invention, there is provided an in-line fluid pump controller for activating and de-activating a fluid pump which is configured to pump fluid through a fluid line. The fluid in the fluid line is characterized by a flow rate and a pressure. The pump controller is provided with a housing which is connectable in fluid communication with the fluid line. The pump controller is further provided with a valve body which is disposed within the housing. The valve body is in fluid flow communication with the fluid of the fluid line and is sized and configured to move in response to the flow rate of the fluid. The valve body has a first position when the flow rate of the fluid is below a threshold flow rate and a second position when the flow rate of the fluid is above the threshold flow rate. The pump controller is further provided with a pivoting lever arm which is rotably connected to the housing. The lever arm is sized and configured to move in response to the pressure of the fluid.

Abstract: The present invention relates to a fluid actuating valve, wherein the valve body (1) comprises a longitudinal tubular body (11) and a transversal cylinder body (12), the longitudinal tubular body (11) defines a longitudinal fluid passage (113), and the transversal cylinder body (12) defines a valve chamber (121), a transversal well (114) is disposed in the middle of the longitudinal tubular body (11), and the upper surface (116) of the transversal well (114) is served as a valve seat. A valve core assembly (3) is provided in the transversal well (114), which engages with the inner wall of the well and the valve seat and is lifted by the pressure fluid coming from the valve inlet to open the valve. A pressure-releasing hole (1111) is provided at the outlet side of the longitudinal tubular body (11) to connect the valve chamber (121) with the longitudinal fluid passage (113) to the outlet side.

Abstract: The present invention pertains to a dual-function hydraulic valve (1), i.e., a control valve and a pressure reduction or limitation valve at the same time. The inventive combined hydraulic valve (1) encompasses a valve casing (2) with a first central pressure connection (P), a second central pressure connection (Br) and a movable flow check piston (7) in the valve casing (2). The flow check piston (7) presents a pressure surface (16) enabling it (P), when the first central connection is put under supply pressure (P.sub.p), to move from its basic position against an opposing force proportional to said supply pressure (P.sub.p) It also presents a first control ridge (40) and a second control ridge (41). The first control ridge (40) is used to link the first central pressure connection (P) to the second central pressure connection (Br), starting from a first set minimum displacement of the flow check piston (7) which corresponds to a lower threshold value (P.sub.1) of the supply pressure (P.sub.p).

Abstract: The invention relates to a valve with a piston which is movable to and fro in a housing between an open and a closed position, wherein the piston has a first contact zone which in the closed position comes into contact with a second contact zone on the housing. The first contact zone on the piston is constructed as a cone which increases from a first diameter to a greater second diameter. The second contact zone on the housing is constructed as a flexible lip. The piston is configured in such a way and the flexible lip is deformable in such a way that--when the valve is installed--the piston can be pushed through the opening of the flexible lip in the region of the greater second diameter of the conical surface.

Abstract: The invention relates to a starting valve for progressive build-up of pressure in an installation through which pressure medium flows, in which a piston is movable to and fro in a housing between a closed and an open position. Means are also provided for maintaining a low flow of pressure medium--while the piston is in the closed position--between a region with high pressure on one side of the valve seat and a region with pressure building up on the other side of the valve seat. The piston has action surfaces which are exposed to the high pressure or to the pressure building up end which generate force components which push the piston into its open or closed position. The piston moving into the open position when the difference between the high pressure and the pressure building up falls below a threshold value. In the housing one region with high pressure and two regions with pressure building up are provided, the latter being connected to one another by way of a channel disposed in the piston.

Abstract: The present invention uses a regulator in the form of dispensing check valve and a flow restriction arrangement to provide a virtually fail safe system for preventing hazardous discharge of fluid from a pressurized cylinder or tank. A diaphragm controls the movement of a check valve element to prevent discharge of gas from a tank unless a predetermined vacuum condition exists downstream of the check valve. A capillary tube or other structure that provides capillary size opening minimizes any discharge of gas in the unlikely event of a failure of the regulator. This system is particularly useful in the delivery of arsine gas and provides multiple safeguards against accidental discharge.

Abstract: A valve system for starting/restarting an oscillating controller of the type that uses a source of pressurized gas to provide controlled pulses of the pressurized gas to a pump, such as a chemical injector pump. The start/restart valve includes a valve element that is closed by a valve spring when the pressure of the pressurized gas source drops below a predetermined minimum and is opened upon the pressure increasing to a second predetermined pressure higher than the predetermined minimum pressure to thereby provide a higher pressure for starting or restarting the oscillating movement of the controller. The start/restart valve includes a detent mechanism for maintaining the valve element in either the open or closed position until the gas pressure reaches the appropriate pressure level for switching to the opposite position. The opening of the valve element may be caused by the gas pressure being applied directly to the valve element or indirectly through a diaphragm in alternate embodiments.

Abstract: A pressure regulator apparatus and method for controlling the pressure in a pressure system is disclosed. The pressure regulator broadly includes a pressure transducer and a regulator control circuit. The pressure transducer measures the pressure of the pressure system, and the regulator control circuit controls the pressure in the pressure system in response to the pressure reading of the pressure transducer. The regulator control circuit compares the measured pressure to a predetermined set-point value for maintaining the pressure within a predetermined optimal pressure range.

Abstract: The gas-pressure controller according to the present invention is characterised in that an obturator disc (9) is connected to a valve spindle (7) on the inlet side so that it can move axially. The obturator disc (9) is pressed by an elastic component in the "open" direction and opens to give a flow channel (3) when the output pressure is above a minimum value. The obturator disc (9) closes off the flow channel (3) when the output pressure drops below the minimum value leaving an extremely small flow aperture (12). The gas-pressure controller proposed is intended for use in medium-pressure applications. The controller starts up again automatically after a gas failure.

Abstract: An improved check valve for selectively controlling the flow of fluid through a valve seat. A spring biases a plunger against the valve seat when the fluid is stationary. Movement of the fluid pushes the valve plunger against the spring to open the aperture of the valve seat. An actuator selectively exerts a force against the plunger to close the plunger against the valve seat. In one embodiment of the invention, the actuator directs a pressurized fluid against a second end of the plunger, and a seal prevents leakage of such fluid toward the plunger first end in contact with the valve seat. A cavity between the seal and the plunger first end can be vented to the atmosphere to maintain the pressure differential created by the pressurized fluid against the plunger second end.

Abstract: Disclosed is an assembly for unseating a seated traveling valve ball, and pumps utilizing such an assembly. The assembly generally includes a tubular member having therein a piston with an actuator for engaging the ball. Mechanical advantage is provided either by providing a sealing area of the piston that is greater than the sealing area of the seat valve and/or by providing a engaging member suitable to strike to seated ball asymmetrically with respect to the vertical axis through the center line of the ball.

Abstract: An apparatus for producing a fresh air stream, has a blower connectable at a pressure side with an exhaust gas conduit of an internal combustion engine of a motor vehicle, a fresh air supply element communicatable with the exhaust gas conduit, a check valve provided between the blower and an opening of the fresh air supply element into the exhaust gas conduit, a cut-off arranged in the fresh air supply element between the check valve and its opening into the exhaust gas conduit and having a closing member loaded with a spring force toward a closing position, an actuating member for the closing member, and a bypass branching from the fresh air supply element so that a pressure which builds when the blower operates and is supplied through the bypass to the actuating member for the closing member acts opposite to the spring force.

Abstract: A fluid valve device for on-off control of fluid flow through a passage extending between two fluid ports (12, 15) and including a valve seat (17A) comprises a hollow valve member (21) which is movable into and out of sealing engagement with the valve seat and defines a valve chamber (20). The valve chamber (20) communicates with one of the fluid ports (15) through the valve seat (17A) and is associated with a valve member actuating device (A) which translates the pressure of the fluid received in the valve chamber (20) from an inlet (12/14) for the fluid flow into a force acting on the valve member to displace it relative to the valve seat (17A). The valve member actuating device in one embodiment includes a thrust surface (A) on the valve member (21) which is directed away from the valve seat and forms part of the wall of the valve chamber (20). A second thrust surface (C) on the valve member (21) is directed oppositely and defines a chamber (V) which is isolated from the valve chamber and the flow passage.

Abstract: A combination high pressure accumulator/bypass valve assembly suitable for vehicle control systems such as anti-lock braking systems and traction control systems employs a stationary seal and a reduced part count favoring economy of manufacture and assembly, and eliminates the dynamic seal/light alloy interface, significantly reducing the potential for failure due to pump body/seal abrasion. A caged spring assembly further encourages ease of assembly.

Abstract: A hydraulically operated adjustable valve for controlling fluid flow through an orifice directly responsive to changes in pressure monitored either upstream or downstream of the valve, suitable for use in high pressure regimes, where said valve is controlled by a piston having a main body, a shoulder and an extension, where hydraulic fluid within a hydraulic bore acts upon said extension to extend said piston, and where a biasing spring acts on the main body in combination with pressurized air within a lower air chamber air acting upon said shoulder to retract said piston. An apertured valve barrier allows the valve to compensate for pressure changes in a high pressure regime upstream of the valve.

Abstract: A mud saver valve has been developed for controlling flow of drilling fluid through an upper portion of a drill string, the mud saver valve in one aspect has a tubular housing, a ball closure rotatably disposed within the tubular housing, the ball closure having a body, a flow channel therethrough, a first body side and a second body side opposite the first body side, a first lug projecting from the first body side and a second lug projecting from the second body side, a sleeve assembly movably disposed within the tubular housing, the sleeve assembly having a first and a second actuator e.g, dogs, to engage corresponding first and second lugs of the ball closure to open or close the ball closure in response to fluid pressure conditions as well as engagement and disengagement of the tubular housing with the drill pipe against the force of a coil spring disposed within the tubular housing.

Abstract: A method of and apparatus for testing an engine or compressor wherein one of an inlet and an exhaust valve (19) is actuated by a hydraulic piston and cylinder arrangement (11) and the flow of hydraulic fluid to the piston and cylinder arrangement (11) is controlled, provides variation of the motion of the valve (19) by adjustment of a control (14, 10) for controlling the hydraulic fluid. Preferably the control is programmed such that the motion of the valve (11) corresponds to the motion that would result from the use of a particular camshaft in the engine or compressor to control valve motion.

Abstract: A pilot actuator and a pilot actuated tank vent valve that comprises: (a) a vent valve body having a pallet which seats on a nozzle to seal the valve; (b) a pallet actuator mounted on the vent valve body and mechanically linked to the pallet, the upper surface of the pallet actuator being in fluid communication with the pressure in the tank through; (c) a pilot valve mounted on the diaphragm actuator and having (1) a spring loaded sensing actuator, (2) a spindle connected to and operated by the sensing actuator, (3) an inlet port in fluid communication with the pressure in the tank, (4) a first passageway for communicating the pressure from the inlet port to the pallet actuator (5) a second passageway for communicating the pressure from the inlet port to the under side of the sensing actuator and (6) a seating mechanism connected to the spindle for sealing an opening between the first passageway and an outlet port, the first passageway being offset from the inlet port and preferably laterally to the second pa

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: A device is proposed which has a nozzle, in particular constructed to resemble a Laval nozzle, as a control device for setting a prescribed fluid mass flow and in which for the purpose of varying the flowing gas quantity the nozzle cross section or the nozzle geometry can be variably set during operation.

Abstract: A combination valve has a pneumatically actuated shut-off valve integrated in a valve housing and operative for blocking and releasing a flow between a valve inlet and a valve outlet. The shut-off valve has a valve member which is spring loaded in a valve closing direction. A check valve is integrated in the valve housing, provides blocking of the flow from the valve outlet to the valve inlet and has a closing member formed by a flat spring. A stroke guard limits an opening stroke of the closing member. The valve member of the shut-off valve is arranged at a side of the flat spring which faces the valve outlet and forming the stroke guard of the check valve. A valve plunger is axially guided in the valve housing and centrally extending through the flat spring, and control piston with which the valve member is connected through the valve plunger is loaded with a suction pressure for opening the shut-off valve and ventilated for closing the shut-off valve.

Abstract: A pressure relief valve includes a fluid flow channel (6, 19, 21) through which an initial flow of fluid passes in use, and a valve opening member (23) responsive at a predetermined fluid pressure to open the valve (13) and allow an increased fluid flow therethrough. The valve opening member (23) is located substantially centrally in the fluid flow channel (6, 19, 21) to ensure it is always exposed to the fluid flow. Part of the flow channel (21) is formed by part of the valve (13). The valve opening member (23) and flow channel (21) are elongated and parallel. A screen (13) on the valve screens the outlet end of the channel (21) from the fluid inlet port (6).

Abstract: A hydraulic pressure control valve, such as a pilot-operated relief valve and such as a direct-acting differential piston relief valve, having a spring chamber pressurized with fluid from a passage though a movable relief piston. The fluid within the spring chamber may be at the same pressure as that at the inlet valve closing pressure to assist a coil spring acting against the inner face of the relief piston. Inlet pressure in the valve working on an area difference between the faces of the relief piston produces the hydraulic force which is opposed by the spring to open the valve. At its other end, the spring transmits force against a movable biasing piston immediately adjacent a closed end of the spring chamber. The biasing piston provides automatic linearly increasing adjustment of the set pressure in response to inlet pressure acting over a greater net area than that of the relief piston.

Abstract: An aircrew breathing regulator having facility for mixing ambient air with oxygen-enriched breathing gas in supplying breathing gas to an end user, includes a demand valve connected between an inlet for receiving oxygen-enriched breathing gas and an outlet for delivering breathing gas to the end user. Ambient air is entrained by flow of oxygen-enriched breathing gas through an injector nozzle to enter an ambient air inlet and mix with the oxygen-enriched breathing gas downstream of the demand valve. Pressure build-up downstream of the demand valve resulting from the flow restricting effect of the injector nozzle causes a pressure feedback onto a head of the valve tending to force it closed. This is overcome by nullifying the action on the demand valve of downstream pressure so that the valve is pressure balanced.

Abstract: In a valve mechanism for controlling oil pressure in an oil path (13) connecting between a hydraulic pump (11) and motor (12) of a hydrostatic transmission (10), a differential piston (23) serving as a relief valve member for gradually increasing the oil pressure has a larger pressure-applied surface area at the side opposite to the oil path than at the side of this path. A throttled oil passage (24) is provided for conducting oil pressure in the path to the larger surface area. The piston is biased by a valve spring (25) through a control piston (26). A receiving member (27) for the spring and a stopper member (28) for the control piston are provided such that they are adjustable in position independently of each other. By this, the manner of increasing the oil pressure may be adjusted in a large variety. The valve mechanism also serves as a relief valve for excluding a possible, excessively high pressure.

Abstract: A fluid pressure safety relief system for a pressure vessel (10) having a main valve member (46) seating on a nozzle ring (38) under a mechanical force of a predetermined amount resulting from a calibrated counterweight (54). An operating rod (55) is connected between the main valve member (46) and a piston (74) having one side in fluid communication with fluid pressure in the pressure vessel (10). A fluid chamber (78) is provided on the other side of piston (74) and a fluid passage (84) from fluid chamber (78) has an outlet at its upper end (86) closely adjacent the nozzle ring (38). Upon unseating of the valve member (46) from the nozzle (38) fluid flows from the fluid chamber (78) to increase the fluid pressure differential across the piston (74) to assist in the movement of the main valve member (46) to an open position.

Abstract: A combination noise suppressor and air filter fits closely around a pressure regulator for milking machines, in such tight-fitting sealed relationship that little or no air or dirt can enter except through a relatively large diameter washable air filter which can be removed and cleaned even while the milking machine is running. The air passing inwardly through such filter also passes through the bars of a cage which support the filter against collapse. A noise suppressor, formed of a laminate of rigid and soft synthetic resin, is provided, and has apertures therethrough through which air passes downwardly after entering through the air filter. After thus passing downwardly, the air is in a chamber that contains the inlet ports of the pressure regulator portion of the combination, the upper wall of the chamber having convolutions which cooperate with sound-absorbing side and bottom walls of the chamber to absorb sound that is generated when air enters into the regulator.

Abstract: A pressure limiting valve has a piston sliding inside a piston bore in a piston guide. A valve spring and a spring plate move in a spring sleeve which has an adjusting screw at an end opposite the spring plate. The spring plate has flow-through openings. The piston extends into a blind bore in the spring plate. The piston guide, which forms the bottom of the spring chamber, has a funnel-shaped recess which extends to the inside wall of the spring sleeve. The spring plate support surface for the valve spring is below the top of the piston.

Abstract: A pressure relief valve for monitoring pressure in relatively large diameter conductors containing relatively high fluid pressure. The valve having housing openings of equal diameter with respect to the conductor and a flow passageway is provided with different diameter coaxial sleeves slidably receiving dual diameter interconnected pistons. The smaller diameter piston forms a flow passageway stop while the larger diameter piston generates a pressure differential with respect to the smaller diameter piston for moving both pistons toward a flow passageway open position in which a piston rod guides the pistons in their axial movement with respect to the sleeves and collapses a pressure collapsible pin supported by a pin cage connected with the valve body in axial alignment with the piston rod for opening the valve passageway and releasing fluid pressure from the conductor.

Abstract: The expansion valve unit, coupled to a lever of a diaphragm by means of a rod unit extending through the internal cavity of the housing, includes heat exchange with the surrounding medium, a rod support at the end of the rod unit opposite the valve unit, being also advantageously associated with a heat exchange unit so as to prevent icing, under the effect of expansion of the breathing gas into the housing, of the mechanical control train of the valve unit, in case of use in a cold surrounding medium.

Abstract: An injector mechanism uses breathing system gas to entrain cabin air to demist and defog the hood and visor of an aircrew chemical and biological warfare ("CBW") suit. The injector includes a needle valve for flow rate adjustment and an aneroid for altitude compensation. The CBW filter is downstream of the negative pressure produced by the injector to purify any ambient air drawn into the system at the negative pressure region. Positive pressure in the system downstream of the CBW filter prevents inward leakage and contamination of the demist and defog gas stream.

Abstract: The regulator second stage for scuba incorporates a pneumatically balanced valve mechanism of high flow capacity which operates without significant influence from friction. The compression spring is suspended between two axially opposed pins to avoid friction producing contact with the housing walls. The valve mechanism is suspended between a dynamic seal and a lever assembly to avoid friction producing contact with the housing walls. The valve controlling lever rotates a ball bearing and collar mechanism in which ball bearings cooperate with notches to provide high mechanical advantage with very low friction. The diaphragm and exhaust valve cooperate to provide stable interaction which conserves breathing gas during all orientations of the regulator second stage.

Abstract: The relief valve assembly has a spring-loaded poppet valve that vents the interior of a transport tanker to the atmosphere when gaseous pressure within the tank exceeds a predetermined limit. Sudden surge protection from a pressure spike created by liquid within the tank during the instant that the tank strikes the ground during accidental roll over is provided to keep the poppet valve closed during the surge condition. A reaction piston having one face that counteracts the face of the poppet valve is exposed to pressure within the tank simultaneously with the poppet valve, but the counteracting effect of that surface is normally overcome by a neutralizing chamber on the opposite side of the reaction piston which is likewise exposed to the interior of the tank.

Abstract: A breathing system regulator for a demand breathing system has adjusting apparatus for adjusting the demand required to open the air inlet valve to permit the user to increase or decrease the tension on the biasing spring urging the valve closed, and to decrease or increase the cushioning effect of a stream of air urging the valve closed. Adjusting apparatus is provided in which an air injector device is adjustably positioned to direct a flow of air between positions for adjusting the pressure at the inlet valve side of the regulator diaphragm to control the amount of breathing effort required of the user to open the air inlet valve.

Abstract: A pressure limiting valve having high flow rates, especially for use as a safety valve with mine props and the like, uses a tubular main valve member whose interior communicates with the valve inlet and has lateral bores opening into the valve outlet when the bores are shifted past a sealing ring in the valve housing. A pilot valve body is received in the tubular valve and the valve spring bears upon the tubular valve. The main valve is shifted by differential pressure.

Abstract: An intake manifold relief valve comprising a valve body (13) having at least two openings, one opening being an inlet (22) for gas and another opening being an outlet (23) for gas to relieve excess pressure, a piston (8) for opening and closing said gas inlet (22) and containing an orifice hole (21) to maintain a constant pressure on both sides of the piston (8); said valve body (13) also cooperating with said piston (8) to form an enclosed gas chamber the size of which is decreased as said piston (8) moves to open said valve, a piston spring (5) applying a force on said piston (8) in addition to that provided by the gas pressure within said chamber to maintain it in a closed position under normal conditions, said piston (8) moving to open said gas inlet (22) when excess pressure within the manifold overcomes the force of said piston spring (5), thereby allowing gas to escape through said valve outlet (23); as the pressure is equalized within the valve through said orifice hole (21), said piston spring (5) wi

Abstract: A pressure-limiting valve having high flow rates, especially for uses as a safety valve with mine props and the like, uses a tubular main-valve member whose interior communiciates with the valve inlet and has lateral bores opening into the valve outlet when the bores are shifted past a sealing ring in the valve housing. A pilot-valve body is received in the tubular valve and the valve spring bears upon the tubular valve. The main valve is shifted by differential pressure.

Abstract: A recirculation valve for cooling a centrifugal pump. The invention comprises a valve casing having a first chamber for connection to a centrifugal pump and a second chamber for connection to a fluid outlet, a recirculation port for redirecting fluid from the first chamber to the centrifugal pump. Between the first and second chambers is a check valve means for permitting fluid flow from the first to the second chamber. Connected to the check valve means is a hollow cylindrical valve stem permitting flow from the first chamber to the second chamber. The check valve means is comprised of a circular disc which opens when the fluid pressure in the first chamber exceeds the fluid pressure in the second chamber and closes when the fluid pressure in the second chamber approaches that in the first and intermediate chambers. A two angle control surface between the check valve disc and the valve casing controls the position of the check valve relative to the flow of fluid past the valve.

Abstract: A pressure-relief valve for the protection of hydraulic units in underground mining, functionable against a sudden overload in pressure, is provided including a valve housing having an upper part and a connection piece, a valve spring lodged against the upper part, a valve piston longitudinally slidable within the connection piece and engageable forceably at one end against the valve spring and having a blind bore and radial bores communicating perpendicular thereto through which a pressure medium is flowable, and at least one sealing ring against which the piston travels which is arranged in the connection piece. The sealing ring is positioned to adjoin the radial bores, consists of a very hard plastic material producing very low friction and has a rectangular cross section.