Abstract: An electronic expansion valve includes a valve needle screw assembly which includes a valve needle, a valve needle sleeve, a washer part, a spring, and a screw assembly. The valve needle sleeve includes a circumferential wall part and a fitting part. The inner diameter of the fitting part is smaller than the inner diameter of the circumferential wall part. The screw assembly includes a lower stopper part, a valve needle support part, and an upper stopper part. The lower stopper part abuts against the washer part. The valve needle support part abuts against the fitting part of the valve needle sleeve. The upper stopper part abuts against the spring. The distance between the valve needle support part and the washer part is D1; the distance between the valve needle support part and the upper end of the fitting part is D2; and D1?D2.

Abstract: An electronic expansion valve includes the valve needle screw assembly which also includes an outer edge guide section, the electronic expansion valve includes an inner edge guide section matched with the outer edge guide section, in the process of the action of the valve needle of the electronic expansion valve, the outer edge guide section of the valve needle screw assembly is matched with the inner edge guide section of the electronic expansion valve, to provide the guide for the valve needle, relatively reducing the deviation of the valve needle relative to the valve port, thereby reducing the eccentric wear of the valve needle.

Abstract: A valve needle assembly includes a valve stem, a valve needle, an elastic element, and a stop structure. The valve needle is connected to the valve stem and axially movable relative to the valve stem. The elastic element is provided between the valve stem and the valve needle. The stop structure is configured to limit axial movement of the valve needle relative to the valve stem so as to prevent the valve needle from prematurely opening the valve hole of the electronic expansion valve under the force of fluid. The electronic expansion valve includes the valve needle assembly.

Abstract: A device for applying a viscous material to workpieces includes a housing, an application channel extending in the housing up to an outlet opening, and a needle valve for opening and closing the application channel at a valve seat. An actuating element is mounted in the housing for rotation about a rotational axis extending parallel to a longitudinal direction in which the valve needle of the needle valve is movable relative to the housing. The actuating element has, in the radial lateral surface thereof, a guide groove extending circumferentially all around and curved in the axial direction in which at least one pin extending in the radial direction engages. The valve needle is connected to the actuating element or the at least one pin so that rotation of the actuating element about the rotational axis causes movement of the valve needle relative to the housing in the longitudinal direction.

Abstract: A proportioning valve for a reverse osmosis system that controls the production of product water by the differential pressure across the purification membrane. By sensing increasing tank pressure to actuate the proportioning valve, the flow of waste water is restricted. Placement of seals within the cavity of the valve, as well as placement of waste water inlet and outlet ports, protects tension components that provide reverse tank pressure from waste water exposure. A needle valve assembly responsive to an actuating assembly that senses tank pressure removes the need for an inlet tank water port while restricting water flow.

Abstract: A valve for a fuel cell system includes a valve housing having a valve seat formed therein. The valve seat includes an orifice formed therein to permit a fluid to flow through the valve housing. A movable member is disposed in the valve housing and is movable between an open position and a closed position. The movable member includes a first end having an elongate portion and a generally conical shaped base. At least a portion of the base is disposed in the orifice of the valve seat when the movable member is in the closed position to militate against a formation of ice across the orifice of the valve seat.

Abstract: A pilot valve is provided with a conical first contact surface, and a pilot valve seat is provided with an annular second contact surface of which an initial contact portion with respect to the first contact surface has a circular-arc cross-section. The first contact surface is formed of a resin with elasticity, and the second contact surface is formed of metal. When a pressure-contact load is small, the first contact surface and the second contact surface come into line-contact with each other. When a pressure-contact load increases, the first contact surface and the second contact surface come into plane-contact with each other.

Abstract: A dispensing device includes a housing having a material chamber in fluid communication with a material inlet port and a nozzle. The dispensing device also includes a valve in fluid communication with the material chamber and the nozzle. The valve includes a tip, a stem, and a seat. The stem is configured to move relative to the seat to control the flow of material exiting the housing through the nozzle. The tip is fixedly attached to the stem at a second distal. The tip includes a rounded head and a neck, the tip being fixedly attached to the stem by inserting the neck into a bore disposed within the stem.

Abstract: A medical valve transitions between an open mode that permits fluid flow, and a closed mode that prevents fluid flow. To that end, the medical valve has a housing with an inlet and an outlet, a rigid member movably mounted within the housing, and a resilient member with a sealing portion. The housing also has at least one relief zone that is in fluid communication with the outlet when the valve is in the closed mode. The rigid member may have a proximal end, a distal end, and a flow channel. The relief zone may be radially outward from the sealing portion. The sealing portion may seal the valve and prevent fluid from passing through the valve when in the closed mode.

Abstract: Manual-valve pistons, manual-valve assemblies comprising the manual-valve pistons, and compressed-gas systems comprising the manual-valve-assemblies are disclosed. A manual-valve piston for sealing a compressed-gas conduit may comprise a head portion, a sealing portion, and a stem portion between the head portion and the sealing portion. When the manual-valve piston in a conduit, a gap is defined between a blocking rim of the head portion that allows compressed gas to be trapped in an isochoric thermal isolation zone adjacent to the stem portion. The isochoric thermal isolation zone protects sealing rings seated in the sealing portion from extremely cold compressed gas being introduced into the compressed-gas system. Manual-valve assemblies comprise a manual-valve piston coupled to a coupling body. Compressed-gas systems comprise a fuel-storage vessel, a refueling port, internal conduits, and a manual-valve assembly disposed in one of the internal conduits.

Abstract: A refrigerant valve has a body with a through bore. Multiple tubes have openings aligned in a ring around a middle of the bore. The tubes lead to larger channels in the body. A needle assembly inserted through an end of the bore reciprocates a needle with a stepper motor and speed reducer to precisely control sizes of the openings. Further advancing the needle shaft after closing the openings to the tubes, engages and slides a bypass sleeve against a return spring force to open a bypass in a side of the valve body. A connector connects the bypass in a first end of the bore to outward opening holes of the channels.

Abstract: A miniature needle valve having an improved internal body-to-bonnet metal-to-metal seal. The body seal incorporates a novel dovetail feature that improves the metal-to-metal contact forces as pressures increase. The space requirements of the seal are minimized in order to fit within a miniature valve body. The valve body can use dual outlet passageways to further minimize space requirements and improve the valve's flow characteristics. The body-to-bonnet seal improvements increase the pressure limits of the valve beyond similar-sized miniature needle valves of the prior art.

Abstract: A method for producing a fuel injector and a fuel injector for internal combustion engines, having a control valve with an electromagnetically actuatable valve needle; a coil is received in a magnet cup made of magnetizable material. At least one clamping sleeve, with a slot extending between the face ends of the clamping sleeve, is received in the magnet cup.

Abstract: A solenoid valve for use in an actuator for controlling brake hydraulic pressure includes a valve housing, a movable core having an integral valve rod and axially slidably received in the valve housing, and a valve body configured to be moved into and out of contact with a valve seat when the valve body moves. The solenoid valve further includes a yoke having a U-shaped section. The flanges of the yoke have first ends that extend substantially along the outer peripheral edges of the coil winding to minimize the length of the flanges and thus the length of the solenoid valve.

Abstract: A needle valve assembly for providing fluid flow control includes a motor; an internally threaded valve body; and an externally threaded plunger threadably engaged with the internally threaded valve body and rotatably and reciprocally driven by the motor, wherein the valve body including a fluid inlet, a fluid outlet, and a flow chamber therebetween, the flow chamber including a flow chamber wall and a flow chamber outlet, the plunger including a flexible needle member reciprocating within the flow chamber outlet to provide variable flow control therethrough, the flexible needle member including a lip seal engageable with the flow chamber wall during reciprocation of the plunger and flexible needle member to provide a seal therebetween.

Abstract: An improved control valve in combination with a pressurized water closet having a housing, a spool rotatable within the housing, a valve stem threading engaging the spool but fixed from rotating relative to the housing and a needle valve extending from the valve stem and into the housing orifice, creating a self cleaning valve adjustable by rotating the spool, which adjusts the depth of the needle valve in the orifice, and thus adjusting the effective opening of the orifice.

Abstract: A valve needle (2), in particular for spraycoating apparatus and their spraycoating devices. The valve needle (2) has a shank (4) and a plunger (8) affixed thereon. The shank (4) is made of another material than is the plunger (8). A preferred material for the shank (4) is an industrial ceramic.

Abstract: The invention comprises a needle valve-related arrangement (1) with a rotating spindle (11) in an enclosure, whereby a rotary movement of the spindle in one direction induces movement in a firs valve part (12) on the spindle in a first direction towards a second valve part (13) and vice-versa. Pressure to create sealing interaction of the valve parts (12, 13) is achieved with the aid of a spring arrangement (35).

Abstract: An improved control valve for a pressurized water closet, having a housing, a spool rotatable within the housing, a valve stem threading engaging the spool but fixed from rotating relative to the housing and a needle valve extending from the valve stem and into the housing orifice, creating a self cleaning valve adjustable by rotating the spool, which adjusts the depth of the needle valve in the orifice, and thus adjusting the effective opening of the orifice.

Abstract: A pneumatically controlled needle valve including a cylindrical body intended to be mounted in a bore of a device, two annular sealing surfaces delimiting a chamber connected to a compressed-air supply device, a first compartment arranged inside the body communicatively with the chamber, a second compartment, a piston separating the first and second compartments, a rod having the piston secured thereto, the rod protruding axially from the body, a needle disposed on the rod intended, depending on a position of the needle, to bear or not to bear against a seat of the bore, at least one spring disposed in the second compartment, the spring acting on the rod in a direction for closing the valve by pressing the needle onto the seat, while air under pressure from the compressed air supply device acts on the piston in the opposite direction, the rod passing with sealing through a front end of the body, and a plug for closing a rear end of the body, the plug being connected to the body in such a way as to be prevente

Abstract: Disclosed herein is a fuel/ignitor valve for metering liquid or gaseous fuel having a servo motor-actuated pintle providing rapid flow rate adjustment response and positive flow shut-off. The fuel flows from an inlet port through a venturi passageway having a throat through which fuel flows at sonic velocity to an outlet port. The pintle has a stem at one end and a contoured head at an opposite end containing a circumferential seal for sealing the throat of the venturi passageway. A motor driven drive nut concentric with the pintle axis is threaded to the pintle stem. As the drive nut is rotated, a pin and slot arrangement causes the pintle to translate along the pintle axis. A force distribution assembly comprising a pair of annular thrust bearings in combination with annular thrust washers is disposed around the drive nut adjacent to each side of an annular flange of the drive nut. This assembly absorbs pressure loads acting on the pintle which would otherwise be transferred to the motor.

Abstract: An electronic expansion valve for a cooling cycle includes a valve housing having intake and exhaust holes and an orifice formed on the exhaust hole. A case is disposed on the valve housing, and a motor is disposed within the case. The motor has a drive shaft extending inside the valve housing. A guide tube is disposed inside the valve housing, the guide tube being vertically or axially movable by rotation of the drive shaft. A needle valve is provided for adjusting an opening of the orifice, the needle valve being mounted on the guide tube. A mechanism is then provided for restricting an axial or vertical movement range of the guide tube and the needle valve, the mechanism being disposed on the drive shaft and the guide tube.

Abstract: A valve with a Laval nozzle, a valve needle movable axially in the Laval nozzle, and an inlet chamber which receives the valve needle foot, in which chamber a radially extended inlet opening terminates. The inlet chamber is separated axially from the inlet plane of the Laval nozzle by a flow channel located therebetween. The inlet chamber is delimited by the valve needle on one side and by one of the valve needle housing sections surrounding the valve needle on the other side. This valve can be used in particular as a metering valve for metering a process gas for a reaction process in a motor vehicle operated by a fuel cell.

Abstract: A high pressure regulator is provided with a valve member, a seat member, and an actuator. The axial position of the seat member may be selectively fixed with respect to the body. The valve member is axially moveable with respect to the seat member, and includes a flange member for engaging a shoulder surface on the body for limiting movement of the sealing member relative to the seat member. The sealing member preferably has a very slight taper of less than 10.degree. for maximizing the sealing area with the seat member. A frustro-conical sealing bore in the seat member preferably has a long axial length which is at least 50% of a nominal diameter of the valve member in sealing engagement with an annular seal between the body and the valve member. The cap housing includes an interior deflection surface for deflecting fluid from the seating bore.

Abstract: A fastening member made of an elastic material is press-fitted in a gapless manner in an insertion hole that divides screw holes in a carburetor body into forward and rearward sections. Screw rods of adjustment valves are screwed into the screw holes and through screw through-holes formed in the fastening member. The screw through-holes have female screw-threads formed by thread rolling. The female screw-threads maintain pressing contact with the surfaces of male screw-threads on the screw rods as a result of the elastic recovery force of the female screw-threads, so that rattling and fuel leakage tend to be prevented.

Abstract: A pilot-operated proportional control electromagnetic relief valve has a needle guide portion snugly fitted around the outer surface of a needle. The needle guide portion guides vertical movement of the needle, and is located at the center of a stopper so as to be coaxial with the stopper. A cylindrical inner wall portion of the stopper is so bored in the lower part of the adapter as to be coaxial with the needle guide portion. A cylindrical outer wall portion to be snugly fitted in the cylindrical inner positioning wall portion is so formed around the outer surface of a seat as to be coaxial with the seat portion. The outer circumferential surface of the needle is snugly fitted in the needle guide portion of the adapter so that the needle guide portion guides the axial travel of the needle, and the cylindrical inner wall portion of the adapter and the cylindrical outer wall portion of the seat are snugly fitted together.

Abstract: A nozzle actuating and adjustment system for applying sealant to a can lid member comprising a nozzle which has a sealant dispensing opening, a needle valve, a needle valve seat surface and a sealant flow passage for enabling flow of sealant material onto the lid member. The needle valve is selectively axially movable between an open sealant applying position and a closed non-flow position relative to the needle valve seat surface. A spring is operatively associated with the needle valve to normally hold the needle valve in the closed lowered position. A needle valve actuator solenoid is operatively connected to the needle valve for selectively causing axial upward movement of the needle valve from the closed position to the open position by a predetermined axial distance to provide a predetermined sealant flow gap in the nozzle to dispense a predetermined amount of sealant material during a predetermined dispensing time period.

Abstract: Needle valves which are seated in valve seats defined by circular edges have DELRIN.RTM. tips for the purpose of minimizing unseating torque which would otherwise be excessive due to the thermal expansion and contraction characteristics of the valve seats and the needle valves. In salt spreaders with aluminum valve seats and steel needle valves, the needle valves become stuck in the valve seats if the needle valves are seated after operation in frigid weather and the salt spreaders are subsequently garaged to raise the temperature of the valve seat and needle valves. By utilizing the DELRIN.RTM. tips, the needle valves do not become stuck.

Abstract: A needle valve in which the needle is moved with respect to its valve seat. The distal end of the needle has a length of a constant, uniform diameter that allows the flow to reach a maximum flow and not change while that finite length is moving within the valve seat. This allows a less critical placement of a stop that prevents further movement of the needle away from its valve seat.

Abstract: An improved fluid control valve assembly employing a needle valve integrally formed on a non-rotating valve stem includes a metering orifice for engaging and forming a fluid seal with the valve needle, and a generally radially extending end face on the valve stem for engaging an opposing wall surface acting to positively stop the valve stem upon fully closing the valve and forming a seal between the metering orifice and valve needle to thereby avoid excessive loads and wear between the metering orifice and valve needle.

Abstract: A armature needle valve assembly for a gasoline fuel injector comprises a needle for contacting and separating from a valve seat. An armature, movable in a first direction and a second direction, causes the needle to contact and separate from the valve seat. A molded plastic connecting means secures the armature to the needle.

Abstract: A pressure balanced gas control valve which uses a bellows to hermetically seal the solenoid from the valve. The gas valve has a valve housing which has an inlet port, an outlet port and a valve seat. Within the housing is a needle valve that moves between an open position and a closed position. The needle valve cooperates with the valve seat to control the flow of gas through the valve. The needle valve is moved to the open position by a solenoid and returned to the closed position by a spring. The bellows is attached to both the needle valve and the housing to prevent gas from flowing into the solenoid and contaminating the solenoid components. The bellows has an effective pressure area which is equal to the needle valve seat area such that there is a net force on the needle valve from the gas pressure that is approximately zero when the needle valve is in the closed position. The net zero force provides a gas valve which does not require additional force to open the needle valve.

Abstract: Disclosed herein is a valve construction comprising a main body having therein a bore extending along an axis, adapted to contain fuel under pressure, and having, at the axially outer end thereof, an axially outwardly diverging conical surface extending at a first acute angle to the axis, and a needle valve located in the axial bore, movable relative to the main body between open and closed positions, and including a stem portion, and a head portion including a first diverging conical surface which extends axially outwardly from the stem portion at a second acute angle greater than the first acute angle and terminates in a first edge which, when the needle valve is in the closed position, sealingly engages the conical surface of the main body, and which has a diameter, a second surface which extends axially outwardly from the first edge in increasingly spaced relation from the conical surface of the main body and then in decreasingly spaced relation from the conical surface of the main body and which terminat

Abstract: A device comprises an armature movable in a first direction and a second direction for causing a needle to contact and separate from a seat assembly. Stop means provide a motion stop in at least the first direction. Damping means are applied to the needle for reducing bounce of the needle when the needle contacts the stop means, by altering spring rates and vibration modes of the needle.

Abstract: A method and apparatus for subjecting a fluid to a controlled pressure drop. Fluid is supplied under pressure with a tangential velocity component to an annular passageway (17). The fluid swirls around the axis of the passageway while flowing axially along the passageway to an outlet (6). A cross section of at least a part of the passageway (17) is adjustable to enable the flow rate to be adjusted for a given pressure loss or the pressure loss to be adjusted for a given flow rate. The outlet (6) includes a second annular passageway (22) surrounding the first annular passageway so that the first annular passageway leads to, and the second annular passageway leads from, a chamber (21) common to the passageways. The second annular passageway is of increasing outer diameter and cross sectional area in the direction of flow from the chamber to the outlet.

Abstract: A valve is provided for accurately controlling the flow of cryogenic fluids such as liquid nitrogen. The valve comprises a combination of disc and needle valves affixed to a valve stem in such a manner that the disc and needle are free to rotate about the stem, but are constrained in lateral and vertical movements. This arrangement provides accurate and precise fluid flow control and positive fluid isolation.

Abstract: A valve assembly structure including a valve body having a fluid passage therein to allow fluid to flow from one end port opening to an opposite end port opening, the valve body including an annular sealing surface cooperative with at least one of the end port openings with a valve stem cooperatively aligned with such end port opening to open and close the same, the valve stem having a collar restrainedly fastened to such valve stem to present an annular collar sealing surface facingly cooperative with the annular sealing surface on the valve body to fluid seal the end port opening when the valve stem is moved to a closed position.

Abstract: A needle valve including a deformable seal positioned between the distal end of the needle and a hard, mechanical seat between the needle and the valve housing. The deformable seal is able to seal around the movable needle but is protected from serious deformation by the hard mechanical seat that is located so as to prevent the needle from entering the deformable seat beyond a predetermined amount. Thus the deformable seal does not extrude due to the entrance of the needle and wear is reduced.

Abstract: A fuel flow delivery system for a gas turbine engine of simple, economical structure including a non-positive displacement centrifugal fuel pump delivering constant pressure, variable flow rate fuel flow through a venturi passage. A conical needle valve is variably positioned within the throat section of the venturi to variably meter fuel flow rate.

Abstract: This refrigeration system expansion valve (10) includes a body (12) having an inlet (20) and an outlet (22) and a valve assembly (24) within the body (12). The valve assembly (24) includes a first port (28) communicating with the inlet (20) and a second, larger port (30) communicating with the outlet (22) and further includes a pin (32) having a first pin portion (34) received by the first port (28) and a second pin portion (36) received by the second port (30). A stepper motor (100) attached to the valve body (12) cooperates with an actuator assembly (60) attached to the pin (32) to induce longitudinal movement into the pin and thereby control refrigerant flow through the valve.

Abstract: A needle valve having improved economy of manufacture and assembly is disclosed in which the tapered end of the needle moves axially with respect to a valve seat having a cylindrical opening but does not rotate. An adjusting means, in turn, is rotated to cause the axial movement of the needle and an alignment means, preferably a sphere, is interposed between the needle and the adjusting means to provide alignment between the two components. The needle itself is also spring biased away from the valve seat.

Abstract: A carburetor and a fuel seeding system having the same including an air suction passageway through which air is fed, and a fuel feeding passageway which is disposed so as to be intersected to the air suction passageway and through which fuel is fed, the air suction passageway and the fuel feeding passageway being intercommunicated to each other. A roughened surface portion is formed on a wall surface of at least one of the air suction passageway and the fuel feeding passageway to generate turbulence in fluid flow and promote carburetion and granulation of the air-fuel mixture due to the turbulence. The tip portion of a jet needle serving as a part of the fuel feeding passageway may be provided with a substantially flat surface portion or a substantially conical surface portion having a vertical angle above 145 degrees.

Abstract: A flow control valve includes a needle (B) which is carried in an elongated housing within an axial bore which is partially closed at one end by a crimp (C) which forms a retaining clip to prevent inadvertent forceful expulsion of the needle from the flow control valve in the event dislodgement or failure of the retaining means which normally positions the needle within the control valve.

Abstract: The stem of a needle valve for regulating fluid flow is threaded into the valve housing. A reversible electric motor, whose shaft engages the stem coaxially, rotates the stem and causes it to move the plug on the end of the stem into and out of a fluid flow port. A helical spring slidably located in a longitudinal bore in the stem is compressed by the shaft to urge the stem toward the housing in order to maintain a working threadable connection between the stem and the housing even when the stem is almost completely withdrawn.

Abstract: A flow regulating valve incorporating a core of ferromagnetic material, a spring which repositions the core, an electromagnet which in turn comprises at least one coil wound onto a magnetic yoke, in which the yoke has an internal cavity in which the core is located so that it can move in an axial direction and a hydraulic circuit controlled by a needle obstructor integrally mounted on the core, is described.

Abstract: Apparatus for regulating the fluid flow produced from a gas pressurized subterranean reservoir. The produced mixture comprising crude oil, water, gas and varying amounts of particulated matter. The apparatus includes a bean which is characterized by a constant diameter flow passage, which limits the flow to a maximum rate. An adjustable valve positioned immediately upstream of the bean flow passage is adjustable to regulate the flow of pressurized fluid from its source, to a desired value less than the maximum level maintained by the bean. The apparatus is structured to allow ready access to the interior to facilitate replacement and repair of internal parts which may become worn or damaged due to constant wear and erosion by the flowing, abrasive fluid.

Abstract: An exhaust valve (10), particularly for a blood pressure measuring apparatus, comprising a valve seat (31) disposed along the course of an outlet channel in a valve housing (11) and oriented toward the pressure side of the valve. A valve body (25) having the form of a slender conical frustum arranged on the pressure side of the valve seat (31) cooperates with the valve seat. Valve body (25) is urged against the valve seat (31) by a closing spring (27). To facilitate controlled release of an elevated pressure contained by the valve, a screw cap (37) is arranged on the valve housing (11) along the axial projection line of the valve body (25), and the valve body (25) is connected to the screw cap (37) through a support bearing (43). A two-stage steep thread (44,45) is provided between the screw cap (37) and the valve housing (11).

Abstract: A combination composed of a conduit for conveying a fluid medium along a linear path under very high pressure and a choke disposed in the conduit, the conduit having an inner wall and the choke being composed of a restrictor having a restrictor opening which is constricted relative to the cross section of the conduit and a movable needle mounted for movement in the direction of the linear path for constricting or closing the restrictor opening. The conduit is made of a material capable of withstanding the high pressures exerted on the inner wall of the conduit by the flowing medium and the choke is made of a very hard and brittle material which is resistant to wear. The choke further includes a central insert member having an outer tubular part fastened to the inner wall of the conduit, an inner part supporting the needle within the conduit so that fluid medium flowing through the conduit flows around the needle, and a member connecting the inner part to the outer part.

Abstract: In this invention, two connecting devices are provided in a burner device to accommodate liquefied gas cylinders/fuel tanks having different mounting cap configurations. The invention also includes a piezoelectric ignition device as part of the burner device for igniting gas provided by the liquefied gas cylinder/fuel tank.

Abstract: A modulating flow control valve comprising a central valve body with a tubular body member detachably supported at an inlet port thereof and providing a valve seat; a plug member is detachably supported in an access bore of the central valve body; and a valve stem, biased toward the valve seat, is extensive through a bore in the plug member. A valve seating member is supportable by a spring stop portion of the valve stem, and with spring biasing of the valve stem, is urged in restricting or sealing relationship with the valve seat, the valve seating member having a valve seating portion of a selected diameter to permit a predetermined maximum flow rate through the valve seat. A stem modulator assembly is provided to move the valve stem in response to a characterizing linkage assembly. Valve setting is provided by an indicia plate and an indicator pin supported by the valve stem.