Abstract: A structurally simplified 2/2-way shutoff valve having a parallel-connected pressure limiting valve. The shutoff valve has a first closing body that cooperates with a first valve seat. The first valve seat is embodied on a second closing body pierced by a conduit, which second closing body, under the influence of a spring, engages a second valve seat attached firmly to a wall which is secured to the housing. The biasing force of this spring is greater than a closing force exerted by an armature upon the first closing body and oriented in the opposite direction from the biasing force. The second closing body and the second valve seat form a pressure limiting valve, which is disposed in the housing of the shutoff valve. The invention is applicable to hydraulic motor vehicle brake systems having an anti-skid and traction control apparatus.

Abstract: A water backflow preventing system is provided for a given area having a sewer line for receiving rain and other water where the sewer line is incapable of carrying, without backup, a given flow rate of water. The sewer line is provided at a given point therealong with at least one overflow opening into which opening water which cannot be handled by the sewer line will rise and overflow. Water storage tank means are buried in the ground below the sewer line and into which the overflow water from said opening will drain and be temporarily stored. The storage tank means have a volume to store many thousands of gallons of water which cannot otherwise flow in the sewer line. A pump is placed in the bottom of the storage tank means. Various float switches are placed in different parts of the system for controlling the pump.

Abstract: A liquid fuel dispensing system having a fuel reservoir and a plurality of remote fuel dispensers, each of which including a suction pump and a pressure regulator valve positioned in the fuel conduit on the inlet side of the suction pump. A pressure relief passage is positioned in the fuel conduit in parallel with the regulator valve. When the vapor pressure of the fuel on the inlet side of the regulator valve exceeds a predetermined pressure, the pressure relief valve opens to permit the flow of fuel through the relief passage within the conduit, thus bypassing the regulator valve.

Abstract: The ABS pump output pulsation dampening device (59) comprises a body (10) having disposed therein a pressure source (12) communicating with an inlet line (14) that transmits pressure to an outlet line (16) via an accumulator or storage chamber (20). The body (10) receives at an open end (13) a spring (38) operated accumulator (30) having an accumulator piston (36) received within said accumulator chamber (20). One end (50) of the accumulator piston (36) includes an interior opening (32) which receives slideably and with clearance a dampening piston (60) and a resilient member (62) which biases the dampening piston (60) into engagement with a seat (15) at the end of the inlet line (14). The dampening piston (60) includes an orifice (64) at an one end (63) adjacent the seat (15) and which communicates with a passage (65) extending through the dampening piston (60).

Abstract: A valve arrangement for use in measuring a wide range of gas flow rates, comprises a valve housing including one inlet for a gas flow and two outlets, one for a low flow rate and the other for high flow rate. A plug is vertically moveable in the housing and includes a large diameter lower end engageable against a seat for closing a large port in the housing, and a small diameter upper end for engagement against an upper small diameter seat in the housing. The large and small seats communicate with the high and low flow rate outlets. Ferromagnetic material forms at least part of each seat with the plug being magnetic for retaining either its upper or lower position depending on the inlet flow rate. With a high inlet flow rate, the plug is lifted from its lower seat to close its low flow rate outlet and open its high flow rate inlet. At low flow rate, gravity causes the plug to drop. This permits the passage of the low flow rate gas through the low flow rate outlet.

Abstract: An outer wall member, such as the wall of a tube, connectable to or integral with the pipe, has an opening in communication with the exterior of the pipe. An inner member is fixedly positioned against the inside of the outer member for separating the opening from the fluid path through the pipe. The inner member has an inner surface defining at least a portion of an inner chamber in communication with the pipe fluid path. The inner and outer members define a labyrinth having an effective cross-sectional area, an inlet end for receiving pressurized fluid from the pipe, and an outlet end in communication with the pipe opening for emitting fluid. A plurality of channels couple intermediate portions of the labyrinth directly to the opening, thereby bypassing respective parts of the labyrinth.

Abstract: An apparatus is provided for controlling flow of fuel vapor and liquid fuel through an aperture in a fuel tank. The apparatus comprises a housing mounted in the aperature, a float valve, a ball, and a mechanism for supporting the ball. The housing is formed to include an outlet, and the float valve is movable in the housing between a closed position blocking flow of fuel vapor and liquid fuel through the outlet and an open position allowing flow of fuel vapor through the outlet. The float valve is formed to include a float chamber and the ball is positioned in the float chamber. The mechanism for supporting the ball is movable relative to the housing. The support mechanism is configured to support the ball in the float chamber so that the ball is able to move in the float chamber in response to movement of the fuel tank to urge the float valve to its closed position.

Abstract: The apparatus functions for monitoring small leakages in order to activate an alarm in the event that there has been more than a predetermined volume of small leakage through the water taps or other part of the system and to automatically turn off a main valve if flow continues therethrough more than a predetermined time and will allow the main valve to open if the discharge of fluid is temporary stopped. The system includes a main valve having a valve seat and a shunt circuit that bridges the valve seat. The shunt circuit includes a volume flow meter and a shunt valve for blocking fluid flow through the circuit. The main valve opens only when the volume in the shunt path exceeds a predetermined value. The shunt circuit includes a throttle that when fluid flows therethrough, provides a pressure drop in the shunt circuit which results in the main valve diaphragm opening when the shunt circuit predetermined value is exceeded.

Abstract: A device is provided for controlling the initial pressurization of a pneumatic system having a pressure supply line with an inlet end and a tail end and at least one pneumatic actuator in the system. The device includes a pneumatic valve having a first and second inlet port and an outlet port. The valve is movable between a first position in which a first fluid passageway connects the first inlet port to the outlet port, and a second position in which a second fluid passageway connects the second inlet port to the outlet port. A user variable orifice is connected in series between the source of pneumatic pressure and the first inlet while the source is fluidly connected directly to the second inlet. Similarly, the outlet from the valve is connected to the inlet end of the pressure supply line of the pneumatic system.

Abstract: A fluid flow control apparatus has an accumulator and valve structure disposed in combination with a restricted passage to provide engagement timing for a friction device. A bypass circuit, including the valve structure on the accumulator, is provided to permit rapid filling of the friction device prior to the commencement of the accumulator stroke.

Abstract: A pressure relief valve for a fuel injection pump of an internal combustion engine contains a valve-closing element capable of moving, by means of an electromagnetic actuation device, between a closed position, in which it rests on a valve seat and closes a pressure relief connection between a pressure chamber and a pressure relief outlet, and an open position where the valve-closing element and a sleeve servo slide gate positioned thereon, separate from a valve seat to create a pressure relief opening for relief of fuel pressure. When the fuel pressure is sufficiently high, the servo slide gate separates from its seat, against the action of a spring, by an additional amount to expose an additional pressure relief connection on the valve-closing element for relief of fuel pressure. Despite only limited motion by the valve-closing element, the pressure relief valve facilitates, with extreme precision, control over the start and the end of fuel injection during the actuation stroke of a coordinated fuel pump.

Abstract: A purge module is provided which provides gas to an enclosure at a first flow rate in order to purge the enclosure of harmful gases. After the pressure within the enclosure has reached a predetermined level, a sensor enables gas at a low pressure to be supplied to the enclosure after a predetermined time has passed. The purge module also enables power to be supplied to the device being purged at the same time the purge gas flow rate is changed.

Abstract: There is disclosed a flow control apparatus for a power steering device in which an operating fluid discharged from a pump is delivered to a power steering device through a restricted passage, and the fluid flow is adjusted by a spool valve movable in response to the pressure difference across the restricted passage. The spool valve contains a first relief valve operating at a first setting pressure in response to the fluid pressure transmitted from a passage located at the downstream side of the restricted passage through a connecting passage. The spool valve also contains a second relief valve operating at a second setting pressure higher than the first setting pressure, but lower than a allowable maximum load pressure, in response to the fluid pressure directly transmitted from a chamber located at the upstream side of the restricted passage. During operations under normal temperature conditions, the first relief valve operates when the load pressure reaches the first setting pressure.

Abstract: A water backflow preventing system is provided for a given area having a sewer line for receiving rain and other water where the sewer line is incapable of carrying, without backup, a given fow rate of water. The sewer line is provided at a given point therealong with at least one overflow opening into which opening water which cannot be handled by the sewer line will rise and overflow. Water storage tank means are buried in the ground below the sewer line and into which the overflow water from said opening will drain and be temporarily stored. The storage tank means have a volume to store many thousands of gallons of water which cannnot otherwise flow in the sewer line. A pump is placed in the bottom of the storage tank means. Various float switches are placed in different parts of the system for controlling the pump.

Abstract: A filter head assembly includes a relief valve assembly therein, and is adapted for use in a spin-on filter or the like. When the relief valve assembly is in a closed mode of operation, fluid flow through the filter head, and an associated filter, results in conventional filtration. When the relief valve assembly is in open mode of operation, the filter is substantially bypassed permitting fluid to flow directly through the filter head, with filtration. The relief valve assembly includes a movable piston member therein, which opens and closes for the respective flow passage outwardly from a lateral takeoff port. Any substantial, undesirable, lateral forces acting upon a piston member may be substantially reduced by means of a lateral pressure release system provided according to the present invention. Generally, the lateral pressure-relief system comprises an annular recess formed in the piston member.

Abstract: A heater control valve comprising: a valve body defining a chamber and a bypass passage extending therefrom. A first conduit in fluid communication with the bypass passage for defining a first inlet port and a first exit port adapted to communicate coolant to an external device. A flexible divertor mounted in the bypass passage and extending into the first conduit for diverting fluid into the bypass passage as a function of flow rate. A second conduit, in communication with the chamber defining a second inlet adapted to receive flow from the external device and a second outlet.

Abstract: A heater control valve comprising: a valve body defining a chamber and a bypass passage extending therefrom. A first conduit in fluid communication with the bypass passage for defining a first inlet port and a first exit port adapted to communicate coolant to an external device. A second conduit, in communication with the chamber defining a second inlet adapted to receive flow from the external device and a second outlet. The valve body further including a first seating surface disposed about an upstream end of the bypass passage and a second seating surface disposed about the second inlet, and a bypass valve, rotatable from a first position in sealing engagement with the first seating surface to a second position in sealing engagement with the second seating surface, and an actuator, for rotating the bypass valve from the first position to the second position in response to control signals.

Abstract: A gas valve for controlling the flow of a combustible, gaseous fuel to a burner employs a modular construction and is configurable to be fast or slow opening, to be step opening or to provide two firing rates in accordance with external signals applied thereto.

Abstract: A valve assembly for controlling the fluid flow to the fuel spray nozzles in the combustion chamber of a gas turbine aeroengine. The valve assembly comprises a main flow valve whereby translation of the main valve beyond a predetermined limit initiates movement of a control valve by a mechanical interconnection means. Movement of the control valve serves to activate means for fluid communication between the main valve and the control valve, venting some of the pressurized fluid flow acting on main valve to the control valve and subsequently to the fluid outlet. The more sensitive operation and hence quicker response time for any given change in fluid pressure at the inlet to the valve assembly results in rapid closure of the valve assembly when the fluid flow is decreasing which discourages dribble occurring.

Abstract: An hydraulic latch device comprises a housing having an inlet (14) for hydraulic fluid, an outlet (17) for hydraulic fluid, and first and second spool means (63,67; 62) slidably mounted in the housing and operable to control the flow of hydraulic fluid from the inlet to the outlet, each of the first and second spool means having resilient means (68;69) associated therewith and being operable to bias the spool means in one direction of sliding movement, the resilient means being arranged such that that associated with the first spool means determines the inlet pressure which places the device in a latched mode in which a first relationship is established between the inlet and outlet, and the resilient means associated with the second spool means determines the inlet pressure at which the device is placed in the unlatched mode in which mode a second relationship is established between the inlet and the outlet, with the latch pressure being higher than the unlatched pressure, and means provided to assist in main

Abstract: A distribution system for filling a baitwell in a boat includes a low pressure pump and a dual check valve. The fluid flow into the system is divided so that the pressure on the pump is reduced, thus enabling the use of an inexpensive pump. The check valve permits the influx of fresh water without the need for recirculating the existing water in the baitwell and also prevents backflow from the baitwell.

Abstract: A fluid flow control valve in a fluid flow control circuit comprises a cavity, first, second and third ports open to the cavity, and a valve member for selectively closing the first port or the second port. The third port serves as an input for receiving fluid under pressure and the other two ports serve as to outputs for this fluid each extending to an associated outlet. A solenoid causes an armature to rotate about a lining so that a lever on the armature is arranged for selectively opening and closing the outlets to close the output associated with this outlet. The valve member is responsive to pressure drop at one or other of the outlets to close the output associated with this outlet. Downstream of the valve there are ducts extend from between the input and each of the outlets for supplying fluid received from the input.

Abstract: A system for regulating pressure in a container. The system includes a membrane pressure regulator with a reference pressure chamber containing a reference pressure, and a vacuum pump connected to the container via the membrane pressure regulator. The system further includes a gas inlet valve connected to the reference pressure chamber for increasing the reference pressure; a gas outlet valve connected to the reference pressure chamber for decreasing the reference pressure; and a regulator connected to the gas inlet valve and the gas outlet valve for actuating the valves. The regulator includes a device for generating a desired pressure value for the container and a measuring member connected for providing an indication of the pressure in at least one of the reference pressure chamber and the container.

Abstract: The device has one valve body that can be set at a constant minimum cross-section and another valve body that is not activated until the pressure in a supply connection becomes too high. The valve bodies are accommodated in separate and parallel-streamed valve housings. Since the design allows free selection of the cross-section in the valve housings, extremely wide fluctuations in the concentration of cream can be mastered in accordance with controls technology by means of the second valve body.

Abstract: A multiple high pressure liquid nozzled gun system and flow controller therefor. The flow controller permits the connection of two guns and allows activation or de-activation of one gun without affecting the other gun. The flow controller has multiple internal channels which re-direct liquid flow upon activation or de-activation of a gun. The flow controller has high pressure channels through which liquid under high pressure flows to the gun nozzles and alternate channels through which liquid may flow when the guns are in a trigger-released or "dump" mode permitting liquid to flow through the controller, to the gun, and out of the gun's dump port.

Abstract: An automatic gas distributing device delivers gas at a constant predetermined pressure from one of a plurality of high pressure vessels arranged in a ring connection. The device has flow paths corresponding to the high pressure vessels, and is controlled by the direct application of pressures of the gas contained in the associated vessels to the relevant stop valves. The device automatically sets into operation a high pressure vessel having a lower gas pressure than other vessels. The device interrupts the high pressure vessel in operation when the gas pressure of the vessel is reduced below a control pressure, and actuates the succeeding vessel.

Abstract: In a process in which a compressor feeds gas to a manifold which in turn supplies a controlled flow of gas to each of a plurality of users in parallel operation, method and apparatus are provided for controlling the back pressure acting against the compressor. The back pressure is manipulated to substantially optimize operation of the compressor. Since user demand for the gas varies over wide ranges, the control system automatically reduces back pressure acting against the compressor during periods of low loads by incrementally opening the control valve to one of the plurality of users. The reduced back pressure causes each on line control valve to move toward a more open position to maintain its set point. The pressure reduction continues in increments until one of the plurality of on line control valves reaches a maximum desired open position.

Abstract: A static pressure gas bearing apparatus equipped with a static pressure gas bearing that can support in floated state the rotating shaft of the turbocharger to be placed on an internal combustion engine comprises an air pump device for pressurizing and supplying a gas, an accumulator for storing the pressurized gas supplied form the air pump device, a pressurized gas supply passage device for connecting the accumulator to the static pressure gas bearing, a bypass passage device for connecting the air pump device to the static pressure gas bearing by bypassing the accumulator, and a control device for controlling the opening and the closing of the bypass passage device in response to the internal pressure of the accumulator.

Abstract: Clean-gas continuous-flow intermediate storage plant having at least one high-pressure accumulator, at least one low-pressure accumulator and at least one pressure-increasing compressor connected therein, and having a connection with a gas distribution line, comprising an input line to the low-pressure accumulator, and an output line from the high-pressure accumulator both connected to the gas distribution line, a connecting line connecting the low-pressure accumulator and the high-pressure accumulator to one another and having at least one pressure-increasing compressor inserted therein, and valves built into the input line to the low-pressure accumulator and the output line from the high-pressure accumulator as well as into an output line from the low-pressure accumulator and an input line to the high-pressure accumulator and respective pressure sensors connected to the valves for controlling the valves.

Abstract: A filter assembly including a housing and a filter element which includes a bypass/reverse flow valve coaxially disposed within the housing with the filter element and includes a central opening therethrough coaxially aligned with the opening in the filter element through which filtered fluid passes. In the forward flow direction a bypass valve opens responsive to a predetermined pressure differential appearing across the filter element to permit unfiltered fluid to flow from the source to the load without passing through the filter element. In the reverse flow direction, from the load to the source, a check valve closes and applied full load pressure to the reverse flow valve causing it to open with a second differential pressure which is lower than the bypass differential pressure to thereby permit free flow of fluid from the load to the source without passing through the filter.

Abstract: A hydraulic volumetric proportioning valve which may be installed in pre-existing hydraulic systems such as aircraft landing gear extension and retraction systems to independently regulate and vary the rate of hydraulic system operation at desired stages of system operation in response to the volume of fluid flow through the system during each stage of system operation.

Abstract: An assembly for use in a system for heating water comprises a heat exchanger for heating cold water to produce overheated hot water and a blending chamber in which the overheated hot water is mixed with cold water to produce blended hot water. An inlet valve controls the flow of cold water to the heat exchanger. A bypass valve controls the flow of cold water into the blending chamber. A flow restrictor restricts the flow of cold water from the bypass valve into the blending chamber when the demand for blended hot water increases above a predetermined amount.

Abstract: Snap-action operation of a servo diverter valve (70) and an associated pressure responsive switch (115) is achieved by controlling the pressurization and depressurization of the valve with a nozzle (140) operated by a pressure responsive bellows actuator (160) disposed in a chamber 145 having a flow restrictor 220 in an outlet thereof.

Abstract: Method and apparatus for controlling fluid leakage from sections of a pressurized fluid system adapted to provide fluid at line pressure to equipment associated therewith includes means for sensing first and second conditions indicative of non-use and of a usage demand respectively of the equipment and for generating a signal indicative of one of the conditions and control unit means for selectively isolating and effecting communication between line pressure of the fluid system and the system section in response to the condition-indicating signal. According to a first embodiment, the first non-use and second usage demand conditions are constituted by respective lower and higher rates of fluid flow through the section of the fluid system in which leakage is to be controlled. According to a second embodiment of the invention, the first non-use and second usage demand conditions are constituted by support and non-support of the equipment respectively or non-movement and movement of the equipment respectively.

Abstract: A feed device for a two-phase fluid pump enabling the pump to be supplied with a two-phase fluid having characteristics, especially the volumetric ratio of the gaseous phase to the liquid phase, compatible with the operating characteristics of the pump. The device has a main pipe (10a) and a plurality of auxiliary pipes (10b, . . . 10i) parallel to the main pipe. Each of the pipes can be connected to an upstream supply line of two-phase fluid, and to the downstream pump (6), each of the pipes having an isolation and flow regulating gate (11a, . . . 11i) at its upstream inlet and an isolation and flow regulating gate (12a, . . . 12i) at its downstream outlet, each of the pipes also having means (16a, . . . 16i; 17a; 17i) for introducing a carrier liquid, such as water.

Abstract: Forms of a reaction control valve are disclosed utilizing various control signals with linear and rotary displacement structures to balance flow reaction forces and attain desired signal-responsive positioning. Different flow passage configurations attain different degrees of damping. An embodiment of the valve functions as a flow proportioner.

Abstract: A valve assembly is provided for use with a hydraulic mine roof support, the assembly having uni-directional control means 49 interconnecting first and second pressure sectors of the valve assembly, and further control means 20 embodied in the first pressure sector which further control means is arranged for activation by fluid pressure in the first pressure sector to allow pressure fluid to flow from the second pressure sector to the first pressure sector until the fluid in the first pressure sector is equal to or exceeds the fluid pressure in the second pressure sector.

Abstract: A system which is especially useful in controlling fuel gas flow in a flame atomic absorption spectrophotometer includes a master fluid flow path and a slave fluid flow path connected to receive fluid from a common source connection. A first valve is connected in the master path for controlling the rate of fluid flow therein. A first orifice device is connected in the master path between the common source connection and the first valve. The slave path includes a pressure responsive fluid flow modulating valve having a control connection to the master path between the first orifice device and the first valve. A second orifice device is connected in the slave path between the common source connection and the flow modulating valve. The flow modulating valve is operable in response to the fluid pressure in the master path as reduced by the first orifice device and in response to the fluid pressure in the slave path as reduced by the second orifice device to control the fluid flow through the slave path.

Abstract: A valve system timing device for pipes carrying fluid under pressure operable to control a fluid, so as to define an upstream and a downstream fluid pipe includes a first or by-pass shutter provided with a modulating flowrate limiting device for slowly pressurizing the downstream fluid pipe, a second or operating shutter operable in a self-actuating manner, and an actuator operated by the fluid under pressure, and opening the operating shutter when the differential pressure between the upstream and downstream pipes is decreased.

Abstract: A hydro-automatic valve with a cylindrical housing mounted vertically and having rigid upper and bottom ring shaped rests between which, within the cylindrical housing, interconnected upper and bottom face closure members are freely disposed. The upper face closure member is shaped as a disc with a hole in the central axis and has small legs arranged around its periphery extending vertically downwards with small teeth turned inwards towards the central axis. The small teeth are disposed freely in a shallow ring shaped groove in the surrounding surface of the bottom face closure member, which is shaped with a conical peak in the axis. At the bottom end of the bottom face closure member there is a deep ring shaped groove. This deep ring shaped groove is connected via parallel channels with the space between the upper and bottom face closure member.

Abstract: A controllable two-way valve for pressure and/or flow control uses a cup-shaped piston, the bottom of which forms a large effective surface area exposed to a control flow through a slit which cooperates with an edge of the slider also serving to define the main flow cross section between an inlet and an outlet. A stationary compensating piston within this slider vents the interior of the slider and a control valve set connected to a spring chamber through which the control flow passes regulates the pressure applied to the slider in the spring compartment.

Abstract: A pressure-relief valve has a housing forming a chamber extending along an axis and a valve seat centered on the axis and subdividing the chamber into an outer high-pressure compartment and an inner low-pressure compartment. The seat defines generally the only fluid-communication path between the compartments. A pump and a load can be connected to the high-pressure compartment and a sump to the low-pressure compartment. A valve body is formed with a central radially outwardly open main groove, an outer face exposed in the high-pressure compartment, an inner face exposed in the low-pressure compartment, a radially outwardly open control groove offset axially inward from the main groove toward the inner face, and a diametrally throughgoing control bore at the main and control grooves.

Abstract: A slurry transport system including a pipeline switching device mounted in pipelines so that when any abnormal condition exists in the slurry transport pipeline, the transport medium return pipeline can be used for transporting a slurry while using the slurry transport pipeline for returning transport medium to the point of origin.

Abstract: A steam or the like supply system has two parallel legs of supply, a first leg designed for high-demand flows and for the metering thereof, and a second leg designed for low-demand flows and for the metering thereof. Each of these legs has its own control valve, and an electronic controller responds to a sensed drop in demand to control a program of valve in the low-demand line; similarly, the controller responds to a sensed increase in demand to control a program of valve shut down in the low-demand leg while opening the control valve in the high-demand line. Protective features in the controller assure against response to transient changes in demand and against interruption of a valve-changing operation until the programmed change has been fully implemented.

Abstract: A hydraulic pressure modulation device disposed between a hydraulic pressure source and a selector valve comprising a cylinder; a spool fitted into the cylinder; an accumulator; an actuation chamber formed in the cylinder; a passage openly connecting the chamber to the selector valve; a spring forcing the spool against a pressure in the chamber; a first passage openly connecting the pressure source to the selector valve; a second passage operable to introduce the oil from the pressure source into the accumulator while the outlet pressure of the device increases from a first value to a second value; and a third passage operable to connect the accumulator to an oil tank substantially after the second passage is closed, the passages being formed in the cylinder and the spool.

Abstract: A modulation valve for controlling flow to a fluid consuming device which valve provides a gradual buildup of fluid pressure and during at least part of the buildup restricts flow to the consuming unit. The valve includes a slide movable by a spring on one end and fluid pressure on the other. The slide has a blind bore on the pressure end which is adapted to move over a projection having a restricted passage therethrough. In at least one position of the slide, fluid flow to the consuming unit is through the projection and through a passage in the slide to the consuming unit. In another position of the slide, fluid flow is through the blind bore and through the passage in the slide to the consuming unit.

Abstract: A mixer for delivering a mixture of two gases G.sub.1 and G.sub.2 in proportions respectively and by volume of X/100 and (100-X)/100; X/100 not being allowed to be smaller than a particular value. Each gas circuit comprises a pipe provided with a cock for adjustment of the rate of flow and with a calibrated orifice selected in such manner that for an identical pressure P, the rates of flow of the gases through these orifices are in the ratio X/(100-X), with devices for limiting the pressure of the gas G.sub.2 to that of the gas G.sub.1, as well as for limiting the pressure in both circuits. The invention is applicable to an oxygen-nitrous oxide mixer for anaesthetic purposes, in which the proportion of oxygen in the mixture supplied cannot drop below 25% and the flow rate of nitrous oxide cannot exceed a predetermined maximum.

Abstract: An automatic shut off valve comprising a housing having a main inlet, an outlet, a user inlet and a user outlet. A valve assembly is contained within the housing and is movable between an open and a closed position. In its open position, the user inlet and outlet are fluidly connected in series with the main inlet and main outlet while, conversely, in its closed position, the valve assembly sealingly closes and isolates both the user inlet and outlet from the main inlet and main outlet. A compression spring urges the valve assembly towards its closed position while a fluid flow rate greater than a predetermined amount into the user inlet retains the valve assembly in its open position. Consequently, in the event of an interruption or blockage of the fluid flow between the user inlet and outlet, the compression spring snaps the valve assembly to its closed position thus isolating the inlet and outlet from the main inlet and terminating fluid flow through the shut off valve.

Abstract: A system for controlling flow of fluid along a conduit from a source of fluid under pressure to a consumer device comprises a primary throttle for connection in the conduit and controllable between a first condition in which it is at least partially closed and a second condition in which it is more fully open, and a secondary throttle defining at least one orifice for connection in the conduit and including a member which is displaceable to vary the area of the orifice. A first force dependent upon the pressure drop across the secondary throttle and a second force dependent upon the time integral of the pressure drop across the primary throttle are applied to the member, the first and second forces being oppositely directed, whereby the member is displaced towards a position in which the pressure drop across the secondary throttle bears a predetermined relationship to the time integral of the pressure drop across the secondary throttle.

Abstract: A method and apparatus for withdrawing with a minimum pressure loss a portion of a fluid flowing in a main line wherein the fluid comprises a vapor-liquid mixture. The apparatus uses a flow restriction in the main line with the portion being withdrawn from the low pressure area of the flow restriction. The flow restriction includes means for removing liquid from the flow and combining a metered amount of the liquid with the portion of the flow that is removed from the main line.