Abstract: Valves, internal combustion engines including such valves, and methods of on-board diagnostic leak detection for a crankcase ventilation system using such valves are disclosed. Each valve has a housing defining a first port and a second port in fluid communication with one another and defining a valve seat therebetween. A biasing member biases a poppet sealing member into a normally open position (defining unrestricted flow through the valve) and a commanded actuator is connected to the poppet sealing member. The poppet sealing member has an orifice therethrough defining a restricted flow path, and, upon command, the commanded actuator moves the poppet sealing member from the open position to a restricted flow position in which the poppet sealing member is seated against the valve seat for restricted flow thorough the orifice in the poppet sealing member.

Abstract: The present disclosure relates to a solenoid valve. The solenoid valve includes an armature provided inside the sleeve, a plunger configured to ascend and descend by the operation of the armature, an elastic member configured to press the plunger toward the armature, a magnet core having a through hole in which the plunger and the elastic member are provided and forming an inner space in a longitudinal direction, a valve seat provided in the inner space and on which an orifice penetrating in an axial direction is formed to be opened and closed by the plunger, and a plurality of flow resistance members each including a ring body interposed between the valve seat and the magnet core to generate a flow resistance of a braking fluid, and a slot formed at one side of the ring body to penetrate through the ring body so that the braking fluid passes therethrough.

Abstract: A subassembly for a compressor controls a fluid flow of a fluid between a high-pressure region and a crank chamber pressure region and between the crank chamber pressure region and a suction pressure region of the compressor. The subassembly includes a first electrical control valve, a second electrical control valve, and an electrical control device. Each of the first electrical control valve and the second electrical control valve has a valve member arranged within a valve housing and displaceable between a pair of positions. The electrical control device is adapted to control, during operation of the compressor, a fluid flow between the high-pressure region and a crank chamber pressure region and between the crank chamber pressure region and the suction pressure region by controlling the positions of the valve members.

Abstract: A flow control device includes a stack of annular discs positioned in a flow path. Each disc includes fluid passageways extending between inner and outer perimeters of the disc, with each passageway defining a flow axis extending out of the disc and radially offset from a central axis of the discs. A plug is moveable relative to the discs between closed and open positions. In the closed position, a cylindrical section of the plug is positioned to block fluid flow through the annular discs. In the open position, the annular discs and a tapered section of the plug collectively define an annular vortex chamber. The fluid passageways in the annular discs and the tapered section of the plug collectively impart a rotational flow when the plug is in the open position and as fluid exits the annular discs.

Abstract: In a valve housing modular system, different configurations for a globe valve arranged to adjust a process fluid flow are provided. The globe valve can have a globe valve member movable in translation along a stroke axis. The system can include a housing corpus with a process fluid inlet and outlet, a process fluid passage arranged therebetween, and an actuating opening to introduce the rod for actuating the globe valve member along the stroke axis; and a housing cover for covering the actuating opening. The system can include different adapters for the different functional/structural configurations.

Abstract: Control valves find one of their most important applications in control loops of process plants for controlling the flow rate of a gaseous or liquid medium. To this end, it is crucial that the flow rate can be reliably adjusted and that safe operation, especially with hazardous substances, can be guaranteed. To solve this problem, a hole pattern for perforated plugs (300) of control valves is proposed, which allows the densest possible arrangement of openings (220) on helical lines where the height of the helical lines is minimal and, at the same time, advantageous technical specifications and safety regulations can be taken into account. The pattern allows to generate a very smooth flow characteristic, which facilitates a reliable control of the flow rate. Moreover, the flow rate can be optimized such that the size of the moving parts of the control valve can be reduced to a minimum.

Abstract: In a control device for a flow-through exhaust gas guide section of a turbine for opening and closing a bypass duct to permit exhaust gas to bypass a turbine wheel arranged in a turbine wheel housing of the exhaust gas guide section comprising with an actuating device and a cover element being provided for opening or closing a flow cross-section of the bypass duct, the cover element is a hollow truncated cone with passages provided in the cone-shaped cover element which differ from one another so as to provide for a controllable efficient and quiet exhaust gas flow through the flow cross-section into the bypass duct.

Abstract: A valve arrangement for an aerospace component includes an inlet, an outlet, and an actuator that can be actuated by a heating element. In a non-actuated state of the actuator, the valve is open to allow flow between the inlet and the outlet. The actuator is a single-use effect shape memory actuator that is compressed in the martensitic state along a longitudinal axis of the actuator and integrated into the valve arrangement. Through the activation of the heating element upon reaching a predetermined transformation temperature, the actuator undergoes a change in length, whereby it is gradually pressed against a seal seat that is embodied at the inlet or the outlet.

Abstract: A wastegate valve includes a wastegate flap and a wastegate spindle, in which the wastegate flap and the wastegate spindle are constituent parts of a single, unipartite molded body. The molded body furthermore has a connecting arm which is disposed between the wastegate flap and the wastegate spindle and which has a plasticization region. A method for installing an exhaust-gas turbocharger wastegate valve of this type into a turbine housing which has a wastegate duct, is also provided.

Abstract: A throttle device for varying the pressure of a fluid in a plurality of parallel outlets includes a fluid collector having at least an internal chamber, an inlet and a plurality of outlets for the fluid, and a control element displaceably mounted in the internal chamber of the fluid collector and comprises a plurality of orifices, the cross-section of which can be varied by a relative movement of the control element in relation to the fluid collector. The control element is a sleeve, wherein the orifices are disposed in the sleeve such that they correspond to the outlets of the fluid collector, wherein between the sleeve and the fluid collector seals are provided, such that in a region between of an outside surface of the sleeve and an inside surface surrounding the internal chamber of the fluid collector no fluid communication takes place between the orifices of the sleeve.

Abstract: The present disclosure relates to a charged particle beam system, comprising a noble gas field ion beam source, a charged particle beam column, and a housing defining a first vacuum region and a second vacuum region. A noble gas field ion beam source is arranged within the first vacuum region. A first mechanical vacuum pump is functionally attached to the first vacuum region, an ion getter pump is attached to the charged particle beam column, and a gas supply is attached to the first vacuum region configured to supply a noble gas to the noble gas field ion beam source.

Abstract: A fluid flow control device includes a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet. A valve seat ring is coupled to the body and defines an orifice through which the fluid flow path passes. A cage is also coupled to the body and defines an interior bore, wherein the cage includes at least one passage through which the fluid flow path passes. A throttling element is sized for insertion into the cage interior bore and movable along an axis between open and closed positions. The throttling element defines a sealing surface oriented substantially parallel to the axis. A seal is positioned to engage the sealing surface when the throttling element is substantially in the closed position, thereby to restrict fluid flow through the valve seat ring orifice.

Abstract: A valve includes a valve stem assembly including at least one wall and at least one passage at least partially defined within the valve stem assembly. The at least one passage defines a first opening. At least one portion of the at least one wall defines an erosion site that is configured to undergo contact with solid particles such that a second opening of the passage is defined. The valve also includes at least one sensing device coupled in flow communication with the at least one passage through the first opening. The at least one sensing device is configured to transmit a signal representative of an increased fluid flow through the at least one passage.

Abstract: A containment housing includes a hexagonal portion configured to receive a linear variable differential transformer. The containment housing also includes a housing contact flange adjacent to the hexagonal portion. The housing contact flange has a flange face. The containment housing further includes an external threaded portion formed between the flange face and a containment housing end. The external threaded portion is configured to engage a fuel control housing portion of a fuel control. A length is defined between the flange face and the containment housing end, and a ratio of the length to a width of the housing contact flange is between 8.22 and 8.94.

Abstract: A pneumatic seacock retrofit is provided for convenient closing of all or a portion of the seacocks, whether as a matter of every day convenience or for use in an emergency, in which all of the vessel's seacocks can be pneumatically closed at the same time, leaving the possibility of selectively overriding seacock closure, with all control valves operating to provide a momentary pulse of air to the rotary actuators and then return to a neutral position, leaving the actuators free for further control. Moreover, an operator is free to manually close a valve in the event that the pneumatic system fails.

Abstract: A fastener driving device includes a nose assembly carried by a housing that has a reservoir. The nose assembly has a fastener drive track. At least a portion of the fastener drive track is defined by a movable portion of the nose assembly. A fastener driver is movably mounted in the housing and configured to enter the drive track and drive successive leading fasteners into a workpiece. A head valve is constructed and arranged to be actuated so as to allow the pressurized gas to move the fastener driver through an operating cycle. An actuator is constructed and arranged to actuate the head valve. The actuator includes a trigger valve constructed and arranged to allow passage of the pressurized gas from the reservoir to a chamber above the head valve, and a contact valve operatively connected to the movable portion of the nose assembly.

Abstract: A mono-block arm and plug for closing a wastegate opening includes a shaft portion and a plug portion extending from the shaft portion where the plug portion includes a feature configured to change shape responsive to application of force to close a wastegate opening to enhance sealing of the wastegate opening. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.

Abstract: Systems and methods are provided facilitating control of material flow. A valve comprises a rotating disc, wherein the rotating disc further comprises at least one hole and one closure surface to facilitate opening and closing a material flow path. In an open state a hole is positioned in the flow path, in a closed state a closure surface is placed in the flow path. Further, sacrificial components are included in the valve to reduce the effects of wear. Furthermore, wear of the sacrificial components can be determined without having to disassemble the valve.

Abstract: A diverter damper seal land for installation in a flue gas duct defined by a casing wall, the diverter damper seal land includes: a front seal land and a rear seal land, the front seal land is mountable in the duct by a connection between the base edge and the casing wall and the rear seal land is connected at its base edge to the inner edge of the front seal land and spaced back and radially inwardly from the front seal such that it protrudes radially inwardly behind the front seal land. Another diverter damper seal land assembly includes: a seal land including a front seal land and a rear seal land; a first gusset; and a second gusset spaced from the first gusset, the first and second gussets connected to the casing wall and positioned at the back side of the front seal land to support the seal land in an operative position in the duct.

Abstract: An improved disk-valve fuel injector comprising a self-centering, floating valve seat insert disposed in a valve body. The valve seat insert includes a circular first valve seat and the body includes a circular second valve seat concentric with the first valve seat. A spring urges the valve insert into compliance with a disk-shaped valve head. The valve insert is able to adjust position in all three dimensions, allowing the disk head to mate precisely with both seats, thereby minimizing leakage when the valve is closed, improving metering precision, and extending the working lifetime of the valve head and valve seats.

Abstract: A low-flow diaphragm valve has a flexible diaphragm that cooperates with a portion of a valve body to open and close the valve. The diaphragm may have a dome for seating in a passage between the inlet and outlet of the valve. The diaphragm may have one or more ribs for seating against other portions of the body located around the passage. The valve body may include openings or interruptions to permit fluid to flow through the valve, as well as to permit relatively small particulate matter to flow through even though the ribs contact the body such that the ribs and openings affect flow and may perform screening functions to block or restrict particulate matter of relatively large size from flowing to the passage between the dome and the valve body.

Abstract: An apparatus and method for controlling exhaust produced by a reactive chamber is provided. The apparatus for controlling exhaust may include, for example, a valve body having an exhaust hole for the exhaust to pass through, and may include a first and second valve which regulate the opening and/or the closing of the exhaust hole. A control device may control the operation of the first and second valves based on the internal pressure of the reactive chamber.

Abstract: According to some embodiments, a test fluid may be provided into a chamber associated with a cooling system for an electronic integrated circuit. Moreover, a valve may be partially inserted into an opening of the chamber to seal the chamber. The valve may include a first sealing portion to seal the chamber at the opening when the valve shaft is inserted the first distance. The valve may then be inserted an intermediate distance, between the first distance and a second distance, to unseal the chamber. Note that the valve may include a second sealing portion, offset from the first sealing portion, to seal the chamber at the opening when the valve is inserted the second distance. The valve may further define a passage, between the first and second sealing portions, to permit a flow of the test fluid when the valve is inserted the intermediate distance.

Abstract: According to some embodiments, a first sealing portion is provided on a valve shaft to seal a chamber. The first sealing portion may, for example, seal the chamber when the valve shaft is inserted a first distance into an opening of the chamber. A second sealing portion may also be provided on the valve shaft to seal the chamber when the valve shaft is inserted a second distance into the opening.

Abstract: In a valve, the combination comprising a valve chamber, having a flow inlet and a flow outlet, a valve operator outside the chamber, a stopper in the chamber and operatively connected with the operator for movement toward and away from seat structure in the chamber, to control flow from the valve via the outlet, and the seat structure including first and second seats, the stopper located to seat on the first seat. there being a flexible sealing lip carried by the stopper to sealingly engage the second seat when the stopper sets on the first seat. Relatively movable parts define said operative connection, with configuration and relative movement to allow air inflow to break back siphonage of liquid, and to allow back pressure relief via drain passages.

Abstract: Redundant valve apparatus including a first valve seat and a second valve seat located in the fluid passage of a hollow valve body between the inlet portion of the fluid passage and the outlet portion of the fluid passage and a poppet member having valve seat sealing surfaces for cooperating with and sealing the first valve seat and the second valve seat. One of the valve seats is fixed within the hollow valve body and the other valve seat is movable within the hollow valve body. The redundant valve apparatus also includes an actuator nut for controlling the operation of the poppet member and for moving the movable valve seat to cause the valve seat sealing surfaces on the poppet member to sequentially engage one valve seat and then the other valve seat.

Abstract: A low-flow diaphragm valve is disclosed having a flexible diaphragm that cooperates with a portion of the valve body to open and close the valve. The diaphragm may have a portion for seating in a passage between the inlet and outlet of the valve and may have one or more ribs for seating against other portions of the body located around the passage. While the valve body may include openings or interruptions to permit fluid and small particulate matter to flow through the valve, the ribs and openings block or restrict particulate matter of relatively large size from flowing to the passage between the diaphragm and the valve body. With this structure, the valve will function even when particulate matter is trapped between one or more of the diaphragm portion that sits in the passage and ribs, on the one hand, and the body on the other hand.

Abstract: A covering device for a drain includes a first cover and a second cover. The first cover defines a plurality of openings. The second cover defines a plurality of openings corresponding to the openings of the first cover. The second cover is rotationally connected to the first cover. In a position, the openings of the second cover are aligned with the openings of the first cover in order to open the drain. In another position, the first cover blocks the openings of the second cover while the second cover blocks the openings of the first cover in order to close the drain.

Abstract: A relief valve assembly is disclosed to include a casing, an one-way valve mounted in the fluid input end of the casing for guiding in a fluid, and a relief control valve installed in the casing between the fluid input end and fluid output end and controllable to reduce the inside pressure of the casing, the relief control valve including a guide tube fastened to the casing in fluid communication between the fluid input end and fluid output end of the casing, a valve stem axially movably inserted through the guide tube, an O-ring in a groove around the valve stem between the head of the valve stem and a flange at one end of the stem body of the valve stem, and a spring member connected between the guide tube and one end of the valve stem to hold the valve stem in the close position to close the passage of the guide tube, and a control member fastened to one end of the valve stem outside the guide tube for pressing by hand to move the valve stem to the open position to open the passage of the guide tube.

Abstract: There is provided a valve enabling complete prevention of leakage and a backflow and having durability and less noise, and further there may be implemented a valve capable of predicting the tendency of occurrence of damage on the functions of the valve before the functions of the valve are actually damaged. In a valve having a valve chamber 5 formed between a fluid inlet 2 and a fluid outlet 3, a valve element 6 disposed in the valve chamber 5 is composed of an elastic member and an inelastic member.

Abstract: A venting methodology and system for rapid shutdown of a fuel cell apparatus of the type used in a vehicle propulsion system. H2 and air flows to the fuel cell stack are slowly bypassed to the combustor upon receipt of a rapid shutdown command. The bypass occurs over a period of time (for example one to five seconds) using conveniently-sized bypass valves. Upon receipt of the rapid shutdown command, the anode inlet of the fuel cell stack is instantaneously vented to a remote vent to remove all H2 from the stack. Airflow to the cathode inlet of the fuel cell stack gradually diminishes over the bypass period, and when the airflow bypass is complete the cathode inlet is also instantaneously vented to a remote vent to eliminate pressure differentials across the stack.

Abstract: A new valve device adapted specifically for use with hot erosive flow streams is provided. This valve device has an inner plug head, which modulates and throttles the amount of flow passing through the valve when the valve is open. The inner plug head is shaped so that as the valve plug approaches the closed position, the inner plug head blocks most of the flow path, reducing the flow to a small amount. The valve of this invention has an outer plug head the contacts the valve's outer ceramic seat as the valve reaches the closed position. Contact between the outer ceramic seat and the outer ceramic plug entirely shuts off flow through the valve.

Abstract: A mechanism for controlling forces in a valve assembly such as flow induced forces. The valve assembly comprises a valve body defining first and second flow passages. A valve is movable in the valve body along an axis to control fluid flow between the first and the second flow passages. The valve has first and second control edges that are relatively spaced axially and radially such that the valve includes a radially extending surface between the first and second control edges. First and second restrictions are formed between the first and second control edges and the valve body, respectively. The first and second restrictions form a intermediate pressure region such that when the first and second flow passages are at different fluid pressures with fluid flowing past the valve, the intermediate region acts on the radially extending surface of the valve.

Abstract: A mechanism for controlling forces in a valve assembly such as flow induced forces. The valve assembly comprises a valve body defining first and second flow passages. A valve is movable in the valve body along an axis to control fluid flow between the first and the second flow passages. The valve has first and second control edges that are relatively spaced axially and radially such that the valve includes a radially extending surface between the first and second control edges. First and second restrictions are formed between the first and second control edges and the valve body, respectively. The first and second restrictions form a intermediate pressure region such that when the first and second flow passages are at different fluid pressures with fluid flowing past the valve, the intermediate region acts on the radially extending surface of the valve.

Abstract: A hydraulic seat and holding valve for hydraulically controlling and holding a hydraulic load in a leakproof manner comprises a seat pairing, whose valve cone, which is part of the piston, is capable of adapting itself to the conical valve seat. To this end, the valve piston is supported for pivoting relative to the valve seat. The cone angles of the valve cone and the valve seat are different.

Abstract: Fuel injector, comprising a main tubular body, provided with at least one through pipe which ends in a spray nozzle which can spray the fuel present inside the through pipe, and a shutter unit, which is mobile axially inside the through pipe, from and towards a position of closure, in which the shutter unit itself abuts a sealing surface provided on the spray nozzle, and seals it in a fluid-tight manner; the shutter unit being made of a cup-type body, the base of which is defined by a sealing disc made of flexible material, on which there are provided an annular sealing projection and an annular stop projection, which is co-axial relative to the former; the annular stop projection having a height which is lower than the annular sealing projection, such as to abut the sealing surface of the spray nozzle only temporarily, subject to resilient deformation of the sealing disc itself.

Abstract: A sleeve valve comprises a sleeve and a gate. The sleeve includes an intake, a discharge nozzle section, and a clean-out section. The discharge nozzle section includes a plurality of nozzles. The sleeve is adapted for fluid flow from the intake through a fluid passage and out the nozzles. The clean-out section includes at least one access port. The gate is adapted for sliding within the sleeve in sliding sealing engagement with the interior surface of the sleeve between closed, throttling, open, and clean positions. The gate and sleeve are configured so that the gate, when in the closed position, prevents fluid within the fluid passage from flowing out the nozzles and the access port. The gate and sleeve, when in the throttling position, permits fluid within the fluid passage to flow out some of the nozzles but prevents fluid within the fluid passage from flowing out the access port of the clean-out section and others of the nozzles.

Abstract: A valve for maintaining a given level of liquid in a tank, reservoir, or other container having a liquid-gas interface. Said valve being actuated by a float that rises and falls along with the liquid in the container. Said valve float actuates a series of valves in sequence wherein the higher the float rises, the more valve ports are opened allowing a higher flow rate through the valve.

Abstract: A valve arrangement comprises a valve housing and a shutoff device. The valve housing has a flowthrough passage extending between an inflow opening and an outflow opening. The shutoff device is for closing the flowthrough passage. The shutoff device has a valve seat surrounding the flowthrough passage and a valve cone which is movable in an axial direction perpendicular to the valve seat between an open valve position and a closed valve position. The valve cone corresponds with the valve seat such that, in the closed valve position, sealing surfaces on the valve cone and valve seat come into metallically sealing contact and thus close off the flowthrough passage. Arranged between the valve seat and the valve cone is a soft-sealing seal arrangement which, in the closed valve position, provides an effective seal in addition to the metallic seal effected by the sealing surfaces. The soft-sealing seal arrangement has a sealing element retained on the valve seat.

Abstract: Apparatus and methods for precision batch or continuous flow blending of gases are described. Pulsatile precision metering valves having substantially zero dead space are employed to introduce gases to a mixing chamber or manifold in predictable uniform quantities to achieve precision gas blends according to predetermined criteria. During batch processing, gases to be blended are repeatedly characterized by the change in mixing vessel pressure with respect to time immediately after blending. Estimates of additional amounts of a given gas to be added to achieve a desired final partial pressure of the given gas in the mixing vessel are based on empirical data previously measured and stored for the gas in question.

Abstract: A globe valve is which uniquely shields and effects sealing compression of a soft seal (10) such the valve can be used to control and fully stop flow of fluids of a variety of extremes of pressure, temperature, corrosive capacity and erosive capacity or combinations thereof that are known to destroy soft seals in current soft seal globe valves. The soft seal (10) is completely shielded within an upper (15) and a lower (11) hard seal assembly attached to the end of valve stem (19). Axial movement of valve stem (19) into valve control port (28) to close valve causes contact of conical hard seal surface of upper sheath hard seal (15) with matching upper conical sealing surface (22) of valve body (20) to greatly reduce fluid flow prior to protective lower hard seal (11) and soft seal (10) rings respectively sliding out of protective inner diameter of upper hard seal (15) sheath into equal diameter of valve cylindrical port (23).

Abstract: An automated routing tool for routing interconnections between circuit elements, standard cells and/or cell blocks of cell-based designs which incorporates the best features of both currently known gate array routing techniques with currently known cell-based routing techniques. The invention eliminates the disadvantages of permitting the detailed router to adjust the relative positions of the circuit elements, standard cells and/or cell blocks during the detailed routing process. The method employs a topology manager which iteratively compacts the circuit topology while at the same time optimizing the routing of the interconnections among the circuit elements, standard cells and/or cell blocks of the circuit design. The method employs bin-based global routing, which identifies expandable boundaries and which provides input to a compaction routine which expands or contracts the expandable areas in accordance with the result of the global routing process.

Abstract: A novel valving assembly that provides redundant control, eliminates separate gasketing, and assures proper valve seating, which includes a dual valve disk construction having a laterally extending integral web membrane.

Abstract: A fluid control valve operable in erosive fluid conditions includes a primary soft seat protected by a secondary hard seat. Two dead band areas control the fluid flow on valve opening and closing to spacially separate the soft seat from the flow stream. A diverter is provided to deflect the flow stream away from the soft seat.

Abstract: A normally open solenoid valve is provided for brake system operation which includes a poppet utilizing a spherical end in conjunction with a valve seat to provide the primary control orifice of the valve. A sleeve is inserted into the main body of the valve with an annular edge provided on the poppet near the spherical end which operates in conjunction with the sleeve to provide a secondary control orifice downstream of the primary control orifice.

Abstract: Apparatus and methods for precision batch or continuous flow blending of gases are described. Pulsatile precision metering valves having substantially zero dead space are employed to introduce gases to a mixing chamber or manifold in predictable uniform quantities to achieve precision gas blends according to predetermined criteria. During batch processing, gases to be blended are repeatedly characterized by the change in mixing vessel pressure with respect to time immediately after blending. Estimates of additional amounts of a given gas to be added to achieve a desired final partial pressure of the given gas in the mixing vessel are based on empirical data previously measured and stored for the gas in question.

Abstract: A fluid flow control valve actuated by a solenoid to selectively position the valve by balancing electromagnetic forces, spring forces and fluid forces within the valve. The valve includes a plurality of flow control orifices in series that provide flexible dual slope flow performance characteristics, precise flow control and high flow capability directed to use as a vehicle's evaporative emission control system purge valve.

Abstract: A water faucet includes an inlet, an outlet and an opening formed between the inlet and outlet. A cylindrical member extends upward from the opening. A sleeve is secured to the body. A rod is threadedly engaged in the sleeve. A cap is secured to the lower portion of the rod and includes a peripheral flange dependent from the cap for slidably engaging with the cylindrical member and includes a convex lump for engaging with the inner peripheral surface of the cylindrical member so as to make a water tight seal with the cylindrical member.

Abstract: A humidification chamber for a respiratory humidifier water is maintained by the use of floats which actuate valves to control the passage of water through a water inlet. Two floats are each provided with actuating mechanisms to separately control the respective valve members. The separate valve members are covered by an elastomeric moulding which couples the valve members and provides a seal. The valves are co-axially aligned and the system provides improved safety by allowing for reliable operation in the case where one of the floats fails. An alternative embodiment of the dual valve construction is also disclosed.

Abstract: The flow trim has inner and outer, spaced apart, tubular cylindrical, coextensive, ported walls which project across the inlet of the choke. A tubular throttling collar may be advanced longitudinally through the annular space between the ported walls, to vary the flow area of the ports. The arrangement enables staging of the pressure drop in increments through the ports of the choke. This reduces cavitation.