Abstract: A pressure reducing apparatus and a method of operating a pressure reducing apparatus are provided. The apparatus is operable to reduce the pressure and flow rate of oil being discharged from a well head to downstream processing equipment. The device has central flow channel configured to receive a flow of oil and reduce the pressure in the oil. The apparatus has internal components formed of a ceramic material that resists erosion and wear caused by sand and other debris in the oil. In one embodiment of the invention, a ceramic outer sleeve is disposed in the central flow channel and cooperates with a ceramic inner sleeve having an orifice. The ceramic inner sleeve is interchangeable with other ceramic sleeves having different orifices to modify the pressure and flow characteristics of oil as it is discharged to the downstream processing equipment.

Abstract: A replaceable valve seat ring for a valve assembly has an annular ring body and an open flow passage extending through the ring body. A seating surface is provided on the ring body adjacent one end of the flow passage. A tool accepting region of the flow passage is formed concentric with and at least partially along the flow passage. The tool accepting region is adapted to receive a standard tool head therein for installing and removing the valve seat ring.

Abstract: A chamber port to which a vacuum chamber is connected and a pump port to which a vacuum pump is connected are formed on a valve body of a vacuum regulating valve. A valve plug includes a plate and a nose which is connected to the plate by screw members, and closes the chamber port by a pressure fluid. The maximum outer diameter of the nose is smaller than the inner circumferential diameter of the chamber port. The nose is detached through the chamber port.

Abstract: A valve assembly for a liquid containing tank or the like, having a vortex breaker of novel construction within the tank of liquid, and affixed to an external valve. The valve has a discharge port and a valve body with an outer member which allows the flow of liquid and a concentrically-spaced inner member provided with upper and lower seals to prevent the leakage of the liquid and allow uniform closure of the valve. The inner tubular member is movable vertically such as with a screw thread and associated handle, from a closed to an open position to allow flow of the liquid from the tank to a discharge port.

Abstract: An annular valve seat is formed in a connecting path connecting a first main port and a second main port, a circular flow path wall having a diameter greater than a seat diameter is formed around the valve seat so as to surround the valve seat, a circular outer peripheral wall having a diameter greater than the seat diameter and smaller than a diameter of the flow path wall is formed at a disc-shaped valve member, and a restricted flow path is formed between the flow path wall and the outer peripheral wall when the valve member is fitted in the flow path wall.

Abstract: A needle valve having a soft tip adapted for sealing an annular valve seat of a body port. The soft tip may be defined as two dissimilar circular rod sections of ductile plastic with the larger diameter having a conical taper. The soft tip is pressed into a mating hole in the metal portion of stem up to its annular seat. A thin metal tubular section of the metal stem is cold formed over the soft tip to retain it in place. The metal retainer secures the soft tip in the axial direction and limits the radial expansion of the soft tip while it is cold formed over the annular valve seat of the body port. The metal retainer also limits the axial movement of the stem to its maximum operating position. Under high axial forces, the soft tip does not rotate relative to the valve seat. A resilient high-pressure seal is achieved with this arrangement.

Abstract: A new and improved fully-sealing throttle valve which is capable of selectively varying or stopping the flow of gas from one gas flow channel to an adjacent gas flow channel. The throttle valve includes a valve body in which is slidably disposed a tapered valve plug having a tapered plug sealing surface. A motor operably engages the valve plug for progressively moving the valve plug toward a correspondingly-tapered, complementary valve plug seat in the valve body in order to impede flow of gas between the plug sealing surface and the valve plug seat, through the valve body. The motor is capable of moving the plug sealing surface of the valve plug in firm engagement with the valve plug seat of the valve body to selectively prevent further flow of gas through the valve body.

Abstract: A flow control device includes an opening part through which an upstream side of a fluid flow passage is in communication with a downstream side of the fluid flow passage. A valve element closes the opening part and includes a large flow rate controlling valve element capable of adjusting an opening degree of the opening part, a sealing member provided with a valve hole having an open area smaller than the opening part and formed to be capable of being brought into tight contact with a peripheral wall part of the opening part and a small flow rate controlling valve element capable of adjusting an opening degree of the valve hole. A valve drive device rotates to drive the valve element in a closed direction for closing the opening part or in an opened direction for opening the opening part.

Abstract: A flow regulating apparatus for a fluid, in particular a pneumatic choke valve, includes a housing having an inlet port and an outlet port fluidly connected by a choke channel. A throttling piston is disposed in the choke channel for movement in longitudinal direction between an initial position and an end position. The throttling piston includes a tapered section to define with the choke channel an overflow passage whose cross section is dependent on a position of the throttling piston, wherein the tapered section is configured such that a movement of the throttling piston from the initial position to the end position results in a progressive increase of the cross section of the overflow passage.

Abstract: A flow-rate adjustment valve for fluids, servoactuated by means of an electric motor, comprising a valve body constituted by a tubular cup formed by drawing, which is contoured so as to accommodate a guiding element for a flow control element and so as to engage first intake and discharge tubes formed by drawing at the ports.

Abstract: A fluid flow regulator having a chamber comprising a port opening and a tapered pin disposed within the opening, for controllably restricting the cross-sectional flow area through the port. The tapered pin moves relative to the bore of the port that it is disposed in, under the influence of a pressure responsive diaphragm. A spring biases the pin towards the diaphragm. The diaphragm's movement is unaffected by any misalignment of the diaphragm with respect to the tapered pin and port, and the tapered pin's movement is unaffected by any diaphragm movement not in line with the port.

Abstract: A valve assembly has a valve body having an inlet passageway and an outlet passageway. A flow orifice is disposed within valve body and provides flow communication between the inlet passageway and outlet passageway. A valve seat cooperates with the flow orifice and a variable port valve plug to open and close the valve. The valve plug has a plug body with a conically-shaped smooth tapered wall, a proximal end, and a domed distal end surface that smoothly transitions into the tapered wall. The valve plug is movable between an open position out of contact with the valve seat and a closed position borne against the valve seat. A maximum open position of the valve plug relative to the valve seat can be selectively changed to vary flow characteristics through the valve assembly.

Abstract: A double directional check valve and flow restrictor combination including a housing which contains a pair of axially-aligned check valves and a flow restrictor disposed between the check valves. Dry purge air flows into the housing through the flow restrictor, which facilitates smooth and uniform flow of the air, and out of one of the check valves to a dessicant chamber to dry or regenerate dessicant in the chamber. The housing is fitted with flanges or other connection structures for quick, easy and convenient attachment of the housing to a piping network in an air, nitrogen or other process drying system.

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 pneumatic valve, includes a housing having first and second ports for entry and exit of an operating gas, a main connection line for linking the ports, and a cross bore intersecting the main connection line. A throttle includes a control element which is received in the cross bore and has a control opening with an effective area which progressively decreases from a first end position to a second end position, as the control element moves in a direction toward the second end position, whereby a counterforce is provided to oppose this movement of the control element. Disposed in the main connection line in series with the throttle is a flow orifice, wherein a gas pressure differential upstream and downstream of the flow orifice, as viewed in movement direction of the control element, is utilized to control the effective area of the control opening.

Abstract: Apparatus and a process for separating impurities from a suspension in a flotation cell, including an aeration device for aerating a liquid with a gas until the liquid is saturated. An expansion device expands the liquid saturated with gas to form gas bubbles in the liquid. An addition device adds the liquid containing gas bubbles to the suspension in the flotation cell.

Abstract: A replaceable valve seat ring for a valve assembly has an annular ring body and an open flow passage extending through the ring body. A seating surface is provided on the ring body adjacent one end of the flow passage. A tool accepting region of the flow passage is formed concentric with and at least partially along the flow passage. The tool accepting region is adapted to receive a standard tool head therein for installing and removing the valve seat ring.

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 precision modulating globe valve for controlling the flow of a fluid from zero to a maximum flow rate. The valve plug of the globe valve includes at least one flow modulating channel recessed from the outer surface of the valve plug. The outer surface of the valve plug engages a sealing member positioned along the inner surface of the valve port. The sealing member provides a fluid-tight seal between the outer surface of the valve plug and the valve port. The flow modulating channel is recessed from the outer surface of the valve plug from a minimum flow end to a maximum flow end. The radially recessed area of the flow modulating channel increases from the minimum flow end to the maximum flow end, such that as the valve plug moves past the stationary sealing member, an increased flow rate is created through the valve port.

Abstract: A pressure reducing assembly for high pressure oil wells is disclosed. The assembly includes a metallic body having inlet and outlet channels that are lined with ceramic inserts. The assembly may also include a removable pressure reducing device that is preferably formed of a ceramic material. Pipe spool pieces associated with the pressure reducing assembly transition the narrow interior flow diameter of the assembly to the larger interior flow diameter of downstream oil process piping. The spool pieces have metallic bodies, with flow channels that are lined with ceramic inserts. The ceramic inserts are disposed within the metallic spool, and are preferably designed with a flow channel taper that gradually increase the interior flow diameter from that of the outlet channel of the pressure reducing assembly to that of the process piping.

Abstract: A chamber port to which a vacuum chamber is connected and a pump port to which a vacuum pump Is connected are formed on a valve body of a vacuum regulating valve. A valve plug includes a plate and a nose which is connected to the plate by screw members, and closes the chamber port by a pressure fluid. The maximum outer diameter of the nose is smaller than the inner circumferential diameter of the chamber port. The nose is detached through the chamber port.

Abstract: An extended range proportional valve which can control rates of mass flow over continuous low, intermediate and high ranges has a pilot member mounted on an armature of a solenoid which can be dithered onto and off of a pilot opening in a main valve member which seals a main valve opening to control mass flow rates over the low range by varying the duty cycle and/or frequency of a pulse width modulated current in the solenoid coil. Intermediate and high flow rates are achieved by dithering the pilot valve member with a duty cycle and/or frequency sufficient to raise the main valve member relatively short and relatively long respective distances from the main valve seat.

Abstract: A valve assembly has a valve body having an inlet passageway and an outlet passageway. A flow orifice is disposed within valve body and provides flow communication between the inlet passageway and outlet passageway. A valve seat cooperates with the flow orifice and a variable port valve plug to open and close the valve. The valve plug has a plug body with a conically-shaped smooth tapered wall, a proximal end, and a domed distal end surface that smoothly transitions into the tapered wall. The valve plug is movable between an open position out of contact with the valve seat and a closed position borne against the valve seat. A maximum open position of the valve plug relative to the valve seat can be selectively changed to vary flow characteristics through the valve assembly.

Abstract: The present invention provides a motor-operated valve having no additional stopper for stopping the rotation of a rotor at fully open and closed states of the valve to allow a reduced number of parts of the valve and to prevent a noise otherwise generated by the abutment of the rotor against a stopper. The motor-operated valve includes a rotor 17 having a shaft 18 formed with an external thread 20. The motor-operated valve also includes a needle valve element 6 having a needle valve head 5 at one end portion thereof and an internal thread 16 engaging with the external thread 20 at another end portion. The valve element has a joining portion 14 for joining the valve head to the internal thread 20. The motor-operated valve also includes a main valve body 1 having a guide portion which stops the rotation of the valve element but allows the axial movement of the valve element.

Abstract: A brewing machine with brewing water flow control mechanisms for controlling flow between chambers, includes a filling chamber in fluid connection with a heating reservoir. In one aspect of the invention, a control chamber with a sealable opening is formed about a drain hole in the filling chamber so that water must flow through the control chamber to reach the reservoir, and fluid access to the control chamber is controlled by a seal which engages the opening in the control chamber. Engagement of the seal with the opening in the control chamber is controlled by operation of a lid which covers the filling chamber. In another aspect of the invention, a flow rate control valve assembly is at least partially housed within the control chamber and has a portion which is proximate to the drain hole in the filling chamber connected to the reservoir, whereby a rate of flow from the filling chamber to the reservoir is selectively controllable by adjustment of the flow rate control valve.

Abstract: A fluid control valve, and a seat ring for use in a fluid control valve, have a low pressure drop ratio factor, lessening the pressure reduction across the operating valve. The low pressure drop ratio factor is achieved by modifying the seat ring inlet to form an entrance nozzle passage, which, in combination with a long, widening outlet passage, enables superior performance in valves incorporating the seat ring.

Abstract: A flow regulating apparatus for a fluid, in particular a pneumatic choke valve, includes a housing having an inlet port and an outlet port fluidly connected by a choke channel. A throttling piston is disposed in the choke channel for movement in longitudinal direction between an initial position and an end position. The throttling piston includes a tapered section to define with the choke channel an overflow passage whose cross section is dependent on a position of the throttling piston, wherein the tapered section is configured such that a movement of the throttling piston from the initial position to the end position results in a progressive increase of the cross section of the overflow passage.

Abstract: In a vacuum valve including a main flow path and an auxiliary flow path for connecting a chamber port and a pump port in parallel, a main valve body for opening and closing a main valve seat in the main flow path, and an auxiliary valve body for opening and closing an auxiliary valve seat in the auxiliary flow path, the main valve body includes, in addition to a valve sealing member for opening and closing the main valve seat in a poppet manner, a flow rate adjusting portion in a gradually-tapered shape to be fitted in an inner hole of the main valve seat and the flow rate adjusting portion functions to gradually increase an exhaust flow rate when the main valve body opens after opening of the auxiliary valve body.

Abstract: A beverage dispense device is designed to dispense a chilled carbonated beverage at a temperature close to the freezing point of the beverage without freezing and without excess break out of carbon dioxide. The beverage dispense device comprises a nozzle (19), a valve comprising a valve seat (13) and a closure member (16, 17), the valve being opened and closed by movement of the closure member (16, 17) out of and into contact with the valve seat (13) to allow or prevent flow of the beverage through the nozzle (19), and a flow regulator (18) between the valve seat (13) and the nozzle (19), the flow regulator (18) being adjustable to control flow rate through the nozzle (19) and being in the form of a core member (18) moveable in a flow passageway (15) downstream of the valve seat (13) and spaced from the valve seat, the core member (18) and the flow passageway (15) having matching tapering surfaces.

Abstract: A faucet comprises a valve body having a bore, an inlet port and an outlet port. A plunger is disposed in the valve body and is reciprocated in the bore. The inlet port opens into a fluid passage adapted for connection to a pressurized source, and the outlet port opens into a dispensing spigot adapted to discharge materials from the faucet. A handle having a pivotal lever is disposed in the valve body and engages the plunger to reciprocate longitudinally through the bore. A plug is mounted on the plunger and has axial and radial sealing surfaces. The plug is forced against the axial valve seat when the valve is closed to deform in both axial and radial directions. The plunger is alternatively designed with channels on its exterior and passages through its interior for use with low-viscosity fluids and with a sealing arrangement for use with high-viscosity fluids. The dispensing spigot can be removed to ease access to the plug for cleaning.

Abstract: A solenoid valve includes a plunger that includes a conical plunger tip and an outlet tube that is formed with an outlet passage. The outlet passage includes a first frusto-conical portion into which the plunger tip fits. The plunger is movable between a closed configuration wherein the plunger engages the outlet tube to block fluid flow through the outlet passage and an open configuration wherein the plunger is distanced from the outlet tube to permit fluid flow through the outlet passage. As the plunger moves, there is only one restriction of flow between the plunger and the outlet tube for each position of the plunger. As such, the flow through the valve is linear with respect to the motion of the plunger and the solenoid valve can be used to easily and accurately control the flow rate of fluid therethrough.

Abstract: Filling valve for the metered delivery of a flow of medium, having: a valve housing with a passage having an inlet opening at the top and an outlet opening at the bottom and a valve body which is accommodated in the passage, a lower end of which has a diameter which decreases in the downwards direction and an upper end of which is connected to actuation means for vertical displacement of the valve body between a closed position and an open position of the valve, which respectively serves to block and allow through a flow of medium via the passage and through the outlet opening. A bottom section of the lower end of the valve body has a stepped shape, with a diameter which decreases in the downward direction.

Abstract: In a vacuum valve including a main flow path and an auxiliary flow path for connecting a chamber port and a pump port in parallel, a main valve body for opening and closing a main valve seat in the main flow path, and an auxiliary valve body for opening and closing an auxiliary valve seat in the auxiliary flow path, the main valve body includes, in addition to a valve sealing member for opening and closing the main valve seat in a poppet manner, a flow rate adjusting portion in a gradually-tapered shape to be fitted in an inner hole of the main valve seat and the flow rate adjusting portion functions to gradually increase an exhaust flow rate when the main valve body opens after opening of the auxiliary valve body.

Abstract: A spool slides in a bore to open and close a valve. The spool moves in a first direction until the spool forcibly engages a seat in the bore, closing the valve. The spool moves in a second direction opposite the first direction so that the spool disengages with the seat, opening the valve. Proper configuration of the spool and bore geometries in the vicinity of the seat keeps static pressure from developing that could otherwise retard spool valve opening.

Abstract: A valve including a cylindrical bore having a circular seat at one end thereof, a valve member that is movable in the axial direction of the seat, and control means connected to the valve member, the valve member including a first portion which serves as a closure element, and a second portion which is engaged in the bore and which is shaped to regulate the flow of the fluid at a desired rate depending on the axial position of the valve member, the second portion of the valve member is detached from the first portion and has a cylindrical outside surface of diameter such that it is in sliding contact with the cylindrical surface of the bore; at least one recess is formed in the cylindrical outside surface of the second portion of the valve member so as to define a passage having a predefined shape, and means is provided for permanently holding the two portions of the valve member in mutual contact so that they are displaced axially simultaneously under the action of the control means.

Abstract: Filling valve for dispensing metered quantities of a flow of medium, comprising: a valve housing with a flow passage which has an inlet and an outlet opening; an actuable valve body which is accommodated in the flow passage, for opening and closing the outlet opening; actuating means for moving the valve body to and fro between an open position and a closed position; in which the valve body comprises a transitional part having a substantially circular cross section, which transitional part transits into a pointed end part, the transitional part and the pointed end part merging smoothly into one another via a convexly curved part running into an adjoining concavely curved part.

Abstract: The invention relates to valves usable downhole and controlled from the surface hydraulically via control lines or by other techniques. The valve has a minimum flow passage which is preferably oriented along its longitudinal axis and a lateral flow passage which opens upon movement of a valve member via applied control pressure from the surface. Alternatively, the valve comprises a tapered needle movable in a throat. When the valve member shifts, additional flow area is exposed to control the backpressure of a fluid by way of hydraulic pressure control from the surface via the control line. The hydraulic control can be with a single control line acting on a piston attached to the valve member with a return spring opposing such movement, or alternatively, can be carried out with a pair of control lines to actuate reverse movements of the valve member.

Abstract: A valve controlled by-pass stud mechanism for a structure defining a stud receptacle and having a bleed passage intersecting the stud receptacle and normally containing a pressurized fluid medium. An elongate stud body is positioned in sealed relation within the stud receptacle and has a vent passage and defines an internal valve seat located about the vent passage and also defines a valve receptacle having internal threads. A needle valve is in threaded engagement with the internal threads of the valve receptacle and is movable by its threaded engagement within the valve receptacle between a closed position in sealing engagement with the valve seat and blocking flow of pressurized fluid from the bleed passage to the vent passage and an open position spaced from the valve seat and permitting flow of pressurized fluid from the bleed passage to the vent passage.

Abstract: In the case of a pressure control device for electropneumatic brake systems of vehicles, particularly utility vehicles, an electromagnetically operable intake valve is provided between a compressed air supply and a consuming device of the brake system. The pressure of the consuming device in the form of a brake cylinder is measured by a pressure sensor and transmitted for the controlled actuating of the intake valve to an electronic control unit. The intake valve is constructed as a valve piston which acts with respect to a valve seat and which, on its approach flow end situated upstream of the valve seat, acts such by means of an intake cross-section which can be changed as a function of the piston stroke, with respect to the housing receiving the valve piston. Thus, according to the values determined by the pressure sensor, a controlled feeding of compressed air is permitted corresponding to the selected contouring.

Abstract: A fuel admission valve for metering gas without using a mass flow sensor. The valve uses a flow control element and nozzle, an actuator, a fuel supply pressure sensor, a fuel supply temperature sensor, a flow control element position sensor, and a flow control circuit to meter gas in sonic flow with insensitivity to the discharge pressure.

Abstract: An improved continuously variable micro control valve and an apparatus and a method employing the same for making semiconductors enable a computer to precisely set a driver of the micro control valve such that the accuracy of the control valve in reproducing a flow value for a given setting of the driver is at least 1/1000 of a maximum flow value for a relatively wide range of flow values which can be provided by the micro control valve. The relatively wide range of flow values is at least 1000 to 1 in a disclosed embodiment with a resolution sensitivity of the micro control valve being at least 1/10,000 of the full scale of the relatively wide range of flow values. The improvement in repeatability and accuracy afforded by the micro control valve can result in higher yields in semiconductor making.

Abstract: Pre-set maximum-flow metering and mixing valves and methods of their operation, including limiting maximum axial (longitudinal) withdrawal of a valve metering stem corresponding to its minimally outlet-occluding location at fully open valve position. A sleeved member is threaded within a mating threaded end of a valve housing and about a mating end of an axially (longitudinally) adjustable flow-metering stem member to limit its travel (as by rotation) from seated fully closed position to a fully open position, corresponding to maximum withdrawal of its tapered end portion from its occluding insertion within the fluid outlet.

Abstract: A throttling valve (11) in particular for an airjet loom includes an electric drive (27) for two valve components (17, 19) subtending a throttling gap (25), the drive including motor displaceable in predetermined positions by means of a control and/or regulation unit for setting throtting gaps (25) of predetermined sizes.

Abstract: A fluid valve including a valve body, a flow control member and a cavitation prevention assembly. The valve body has an inlet, an outlet, a fluid passage communicating fluid therebetween, and means for selectively opening and closing fluid communication between the inlet and the outlet. The flow control member is positioned within the fluid passage and has a central passage through which the fluid advances. The cavitation prevention assembly is positioned within the flow passage and is in flow communication with the inlet and the flow control member. The cavitation prevention assembly controls the pressure of the fluid entering the central passage to a level which is sufficiently low to prevent cavitation of the fluid.

Abstract: The present invention relates to a two stage variable flow valve assembly for use in fluid handling. The valve assembly includes a body with a flow restrictor disposed therein to define two internal chambers which are closed at one end by a wall and open at the opposite end by a discharge opening. A valve having a bulb and a profiled valve stem extends axially through and is movable within the internal chambers to open and close the valve assembly for flow therethrough. Flow is halted through the valve assembly when a portion of the profiled valve stem enters the flow restrictor, prior to the bulb's closing of the discharge opening.

Abstract: A flow regulating valve combines two throttle locations in a valve housing. One throttle location is always so adjusted that a constant differential pressure prevails across the other throttle location. Therefore at that second throttle location the through flow depends only on the degree of opening and not on the differential pressure. A cone of the second throttle location comprises at least two individual portions which are displaceable relative to each other and by the spacing of which the effective cross-section of the throttle location is variable. That provides a through-flow limiting effect which is not in the form of a stroke movement limitation. Therefore the full adjusting range is available for adjusting the flow. This flow regulating valve is suitable for controlling flows of liquids in heating solutions.

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: The invention is directed to a spray cooler for regulating the temperature of superheated steam with a stream of cooling water. Its primary inventive feature is directed to a throttle area which has a continuously widening cross section disposed on a piston rod and arranged between the cooling water inlet opening and the nozzles of the spray cooler. The throttle area serves to regulate the pressure the cooling water in proportion to the movement of the piston carrying the throttle.

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 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.