Abstract: A fluid regulator includes a poppet valve within a flow path that selectively allows a flow of fluid to move from an inlet to an outlet. A threaded regulating interface adjusts a spring tension exerted toward the poppet valve and defines a regulated flow of the fluid through the flow path. A fluid purge mechanism is positioned within the threaded regulating interface. The fluid purge mechanism operates along a rotational axis of the threaded regulating interface and adjusts a boundary of the flow path and manipulates the poppet valve to a maximum operating position to define a purging flow of the fluid. A programmable logic controller cooperates with the powered actuator and a pressure sensor to define a closed-loop interface that adjusts the regulated flow of the fluid through the flow path.

Abstract: Gas flow control valve 3, wherein the gas flow control valve 3 comprises a housing 11 with a gas inlet 10, a valve seat 6 arranged in the housing 11, a valve body 5 assigned to the valve seat 6, wherein the valve body 5 is held by an upper spring and a lower spring and is centered by means of a diaphragm 26, and a gas outlet 12 which is positioned downstream of the valve body 5 and which is provided in the housing 11, wherein the valve body 5 is arranged in the valve seat 6 so as to be movable in a first movement direction 17 in order to form a controllable cross section of a passage opening 25 for the passage of gas, wherein the gas flow control valve 3 comprises an adjustable diffuser 13.

Abstract: A pressure regulating valve including a seal seat that defines an opening. A seat stem is moveable between a closed position in which the seat stem engages the seal seat and prevents fluid flow through the opening, and an open position in which the seat stem is spaced from the seal seat and permits fluid flow through the opening. A biasing element biases the seat stem in the closed position. A housing defines a passage that extends between an inlet and an outlet. The seal seat, seat stem and biasing element are positioned in the passage such that movement of the seat stem between the closed and open positions controls flow of the fluid between the inlet and outlet. The housing has an outer wall including a coupling mechanism for fixing the housing inside a channel of a primary regulator body.

Abstract: In one set of embodiments a selected section of tubular stock has its ends welded together to form a pillow-like pressure sensing device with an entry tube and an exit tube each configured to facilitate insertion of the pressure sensing device into the flow path of IV infusate in an IV administration set or system. Fluid pressure in excess of a predetermined amount reconfigures the pressure sensing device from a generally oval configuration to a generally circular configuration to restrict and/or cut off fluid flow into the device while permitting fluid flow from the device to reduce the fluid pressure again reconfiguring the device back to its generally oval configuration and permitting fluid flow into and through the device.

Abstract: An end fitting for use in connecting a gas source in fluid communication to an appliance, includes a nut mounted by a fusible and meltable heat activatable material on a socket having a chamber for receiving a plug. The plug connects to the gas source and the socket connects to the appliance. An O-ring of meltable heat activatable material separates the plug and socket. The socket includes a spring that biases a valve member against the plug and between closed and open conditions, respectively, to block or permit fluid flow from a source and through the chamber. In case of excess heat buildup in the socket body, the heat activatable materials melt but unless the gas source is turned off always allow a predetermined amount of gas to flow.

Abstract: A gas regulating and control system is provided that is configured to be received at a gas regulator installed at a remote location for remotely controlling the gas flow, the system including a gas control module including a plurality of sensors associated with the gas regulator, the plurality of sensors configured to sense a corresponding plurality of parameters associated with the gas regulator. The gas control module is configured to automatically turn off the gas to the gas regulator when one or more of the corresponding plurality sensed parameters is determined to be outside an acceptable range for the sensed parameter.

Abstract: A bleed valve includes a valve housing defining an inlet and an outlet with a flow path for fluid communication from the inlet to the outlet. A poppet head is connected to the valve housing by a primary spring and a secondary spring. The poppet head is configured for movement relative to the valve housing between: a fully open position in which the poppet head is spaced apart from the inlet to allow flow through the flow path, with the primary spring and secondary spring both expanded; a partially closed position in which the poppet head is spaced apart from the inlet but is closer to the inlet than in the fully open position, with the primary spring compressed; and a fully closed position in which the poppet head seats against the valve housing blocking flow through the flow path, with the primary spring and the secondary spring both compressed.

Abstract: An automatic filter cleaning system, e.g., for cleaning a filter in a vacuum cleaner. The cleaning system has an electrical motor that drives/rotates, directly/indirectly, a piston which directly/indirectly opens a filter cleaning valve. The filter cleaning valve may open for a filter cleaning back flow air stream that thus cleans the filter. The piston is spring loaded and a piston guide ensures that the energy accumulated in the spring and piston is released during the rotation of the piston, thereby shortly opening the filter cleaning valve.

Abstract: A regulator first stage for two-stage underwater breathing apparatuses includes a reduction chamber communicating with a high-pressure gas supply through a balance valve, which is influenced by the pressure of the external environment by a balance diaphragm that, by way of a suitable actuator, acts on the valve. The reduction chamber includes one or more medium pressure outlets, having axes parallel to the operating axis of the balance valve. In one configuration, one or more medium pressure outlets are also provided having axes orthogonal to the operating axis of the valve.

Abstract: A pressure reducing valve includes a body, an annular valve seat, a valve element, and a pressing mechanism configured to press the valve element. The pressing mechanism includes a plug provided downstream of the valve seat and having a plug hole, and a pin including a sliding portion and an upstream end, the sliding portion having a shaft shape and being inserted in the plug hole such that a gap is provided between the sliding portion and an inner peripheral surface of the plug hole, and the upstream end being provided upstream of the sliding portion so as to contact the valve element. A fitting length of the sliding portion with respect to the plug hole and the gap between the sliding portion and the plug hole satisfy 0.0005 L<C<0.00908 L, where L indicates the fitting length, and C indicates the gap.

Abstract: A heating assembly can include a switching valve which can include certain pressure sensitive features. These features can be configured to change from a first position to a second position based on a pressure of a fuel. The valve can be used with either a first fuel or a second fuel different from the first. The valve can become locked or be held in either the first or the second position. For example, a set fuel pressure can cause the valve to move to a closed position and the valve can become locked or held in that position. If the pressure decreases, the valve can remain in the locked position. Actuation of a reset switch can allow the valve to move to a new position, such as an open position.

Abstract: An electro-pneumatic controller adapted to use a non-inert fluid as a control fluid includes a base portion and a cap portion removeably secured to the base portion. A non-intrinsically-safe process may be disposed within an interior of the cap portion. A plurality of passageways may be disposed through the base portion. The electro-pneumatic controller may also include a flameproof barrier assembly which may include a plurality of flameproof joints each disposed within desired portion of the plurality of passageways. The plurality of flameproof joints cooperate to at least partially define a first zone, the flameproof joints adapted to prevent or to limit the spread of an open fire or explosion that might occur due to the ignition of the non-inert control fluid.

Abstract: The radius of curvature (SR2) of a surface of a diaphragm presser, which surface is in contact with a diaphragm, is at least 30 mm. The taper angle (?) for a lower surface of a press adapter is no more than 10° relative to a flat portion of a bottom surface of a depression of a body.

Abstract: An air pressure regulator includes a regulator body defining a hollow interior, an air inlet in communication with the hollow interior and configured to connect with a source of pressurized air, an air outlet fluidly coupled with the air inlet, and a valve stem positioned at the air inlet and configured to regulate the pressure of the pressurized air for the air outlet by way of movement of the valve stem relative to the air inlet.

Abstract: A method is disclosed for uniformly cooling a cooling plate of a heat generating device. Sub-cooled refrigerant is flowed through a thermal expansion valve and then into the cooling plate as a two-phase refrigerant where the refrigerant is superheated. Any refrigerant remaining in a fluid state before reaching a sensing portion associated with the thermal expansion valve and exiting the cooling plate can be completely vaporized by a recuperative heat exchanger. The superheated refrigerant is then passed to the sensing portion so that the superheated refrigerant directly transfers heat to a fluid within the sensing portion and causes a pressure change that is communicated to a needle of the thermal expansion valve.

Abstract: A driving apparatus and a valve including the same. The driving apparatus senses a pressure of a fluid medium and generates a driving force. The driving apparatus includes: a drive shaft, a sensing device, a limiting device, a support body, and a protruding member. The limiting device includes a groove, and the protruding member is engaged in the groove. The limiting device can thus automatically limit the rotation of the drive shaft, so as to avoid damaging the sensing device, thereby facilitating maintenance and installation of the valve.

Abstract: Some embodiments of the present invention provide a balance-of-plant system and apparatus suited for regulating the operation of an electrolyzer cell stack. Specifically, in some embodiments, a balance-of-plant system and apparatus is operable to regulate the respective pressures of at least two reaction products relative to one another. Various examples are provided to demonstrate how the respective pressures of two reaction products can be regulated in relation to one another in a pressure following configuration, thereby regulating the pressure differential across an electrolyte layer according to aspects of different embodiments of the invention. Some of the examples provided also include design simplifications and alternatives that may reduce production costs of electrochemical cells configured according to aspects of different embodiments of the invention.

Abstract: A method of controlling a regulator with a pilot device includes periodically detecting an outlet pressure at an outlet of the regulator with a feedback pressure sensor. The method also includes comparing each detected outlet pressure with a set-point control pressure. Additionally, the method includes opening an exhaust valve when a detected outlet pressure is greater than the set-point control pressure so that a loading gas, which is applied to a top surface of a diaphragm of the regulator, exhausts out through the exhaust valve to reduce loading on the diaphragm. The method further includes sensing a loading pressure in the outlet port with a loading pressure sensor after opening the exhaust valve and comparing the loading pressure to a predetermined minimum threshold pressure. When the loading pressure is equal to or less than the predetermined minimum threshold value, the method includes closing the exhaust valve.

Abstract: A damped actuator for a fluid regulator includes a diaphragm disposed in a housing, and a damper arranged to stabilize movement of the diaphragm in response to changes in pressure inside the housing. The damper includes a ball check valve arranged to allow air to exhaust out of the housing when above a preselected pressure. The damper may include interchangeable components so as to be modifiable to have different set point pressures to achieve different backpressures inside the housing.

Abstract: A pressure reducing valve including a balanced valve cartridge. The balanced valve cartridge has a retainer including a central bore. A valve seat and a valve plug are disposed within the central bore and cooperate to open and close the valve. A cap closes one end of the central bore, the cap including a blind bore for receiving a portion of the valve plug. Downstream fluid pressure is transmitted into the blind bore through a hollow portion of the valve plug, thus balancing the valve plug within the retainer.

Abstract: A gas pressure regulator for use with gas delivery systems is provided. The gas pressure regulator includes, in one form, an inlet with an entry portion and a bottom portion. A pocket is disposed proximate the bottom portion of the inlet, and a cavity is disposed within a central portion of the gas pressure regulator. A guide is disposed within a lower portion of the cavity, and a flow of gas through the gas pressure regulator extends through the inlet, changes direction to flow through the cavity, and the flow of gas changes direction to impact the guide prior to flowing through the cavity. The pocket and the guide reduce the amount of particles capable of reaching internal components of the gas pressure regulator, resulting in low sensitivity and high fault tolerance to ignited particles coming through the gas pressure regulator in the event of accidental particle contamination.

Abstract: A water pressure regulator includes a sealing member and a body having a diaphragm assembly. The diaphragm assembly is positioned and secured within the body to define first and second chambers. The diaphragm assembly has a force acting thereon from within the second chamber. The first chamber defines first and second zones and a passageway therebetween. An inlet of the body is configured to provide water to the first zone and an outlet of the body is configured to deliver water out of the second zone. The sealing member is positioned within the first zone. The sealing member seals the passageway by a force of the water in the first zone acting upon the sealing member and by a gravitational force acting upon the sealing member. The sealing member is formed in the shape of a spherical ball. The water pressure regulator may be used in a watering system.

Abstract: In order to achieve seal durability and bring about a damping action for a piston-type pressure regulating valve, a pressure regulating valve of the present invention is characterized by a valve moving member moving in such a manner as to cause communication or block communication between a primary chamber and a secondary chamber within a case, wherein a plurality of central members are arranged between the case and the valve moving member and the plurality of central members are taken to be different materials. It is then possible to bring about both a damping action and seal durability using the central members by providing central members of different materials.

Abstract: A diaphragm control valve has a universal diaphragm mounting location, the diaphragm control valve includes a bonnet, a valve body, a diaphragm, and a clamping washer. The bonnet includes a first clamping surface that transitions into a first annular retention surface formed by a skirt, and the valve body includes a second clamping surface that transitions into a second annular retention surface formed by an upturned annular lip.

Abstract: In a decompression valve, a valve mechanism housed in a body has a valve body that can be seated on a valve seat facing a valve chamber into which high pressure fluid is introduced, and a valve shaft that has one end linked to a pressure receiving member operable in association with pressure of a decompression chamber communicating with a valve hole surrounded by the valve seat and that extends through the valve hole while having the other end facing a back pressure chamber communicating with the decompression chamber, and the valve body is fitted around the outer periphery of the valve shaft.

Abstract: A brake apparatus including a housing with a fluid passage, a piston body disposed within a closed-ended bore of the housing and communicated with the fluid passage, a first elastic member biasing the piston body toward a closed end of the bore, a valve element disposed in the fluid passage, a seat portion coming into contact with the valve element, a rod disposed between a crown surface of the piston body and the valve element, a second elastic member biasing the valve element toward the seat portion, a rod supporting hole portion that supports one end side of the rod, a rod outer circumferential passage portion disposed on the other end side of the rod and having an inner diameter larger than an inner diameter of the rod supporting hole portion, and at least one communicating hole portion that communicates the rod outer circumferential passage portion and the bore.

Abstract: Valve seat apparatus having positive retention for use with fluid control devices are described herein. An example valve seat apparatus includes a metallic ring and an elastomeric ring coupled to the metallic ring and having a sealing surface to sealingly engage a flow control member of the fluid control device. At least a portion of an outer surface of the elastomeric ring includes an annular lip to sealingly engage an annular recess of a body of the fluid control device.

Abstract: A gas releasing and/or regulating mechanism is equipped with a body (1) with a passage, a gas intake (2) and outlet (3), the intake and outlet being connected to the passage; elements to block (5, 6, 7, 8) the passage; mobile elements (9) which associated to the body (1) of the mechanism, define a low pressure chamber (11) below the blocking elements (5, 6, 7, 8), the mobile elements (9) operating the blocking elements (5, 6, 7, 8) depending on the pressure within the low pressure chamber (11). The blocking elements (5, 6, 7, 8) are made of a first shutter (5, 6) and a second shutter (7, 8) below the first in the passage; and the first and second shutters (5, 6, 7, 8) are mechanically connected so that the first shutter (5, 6) closes before the second one (7, 8).

Abstract: A high pressure regulator for compressed gas weapons, and in particular for paintball markers, is situated inside a cylindrical regulator housing which is connected to a source of compressed gas. The cylindrical regulator housing comprises an inlet channel which is connected to a supply of high-pressure gas. A first regulator (H) comprises a first piston movably disposed within the regulator housing for regulating pressure in a first expansion chamber. A second regulator (D) comprises a second piston movably disposed within the regulator housing for regulating pressure in a second expansion chamber. The first piston and the second piston are arranged coaxially within the regulator housing. The high pressure regulator is suitable to be mounted in the foregrip of a paintball marker and reduce an inlet pressure of about 850 psi to a first pressure of about 250 psi and a second pressure of about 100 psi.

Abstract: In order to achieve seal durability and bring about a damping action for a piston-type pressure regulating valve, a pressure regulating valve of the present invention is characterized by a valve moving member moving in such a manner as to cause communication or block communication between a primary chamber and a secondary chamber within a case, wherein a plurality of central members are arranged between the case and the valve moving member and the plurality of central members are taken to be different materials. It is then possible to bring about both a damping action and seal durability using the central members by providing central members of different materials.

Abstract: A control assembly for a fluid flow control device includes a control element, a load spring, and a spring clip. The control element can be movably disposed for controlling fluid flow, and the load spring biases the control element into a predetermined position. The spring clip contacts the load spring at a plurality of points to dampen vibrations experienced by the load spring, thereby reducing and./or eliminating resonance. The spring clip includes a body plate and first and second opposing arm plates extending away from the body plate. Each arm plate includes a proximal end adjacent the body plate, a distal end spaced away from the body plate, and a finger extending upwardly away from the distal end. A corner at an intersection between the finger and the distal end includes a contoured edge for facilitating attachment of the load spring to the spring clip.

Abstract: A paint circulating system back pressure regulator comprises a flow passage for paint, at least part of which is disposed between a fixed structure and a moveable surface which is moveable to vary the width of the flow passage so as to regulate a pressure of paint upstream of the regulator. The regulator is also provided with a chamber having an opening for communicating with a supply of a pressurized fluid for controlling operation of the regulator.

Abstract: A back pressure regulating valve includes a valve body having a fluid inlet, a fluid outlet, a central bore, a bonnet housing a load spring operatively coupled to a diaphragm, and a chamber in flow communication with the fluid inlet. A valve cartridge includes a housing sized to fit within the central bore and including a first portion, a second portion, a valve guide, and a flow passage. A valve seat is disposed in the housing, and a valve plug is shiftable between an open position permitting flow and a closed position preventing flow. The valve plug engages a valve guide, and a spring biases the valve plug toward the open position. A retainer is disposed adjacent the first portion of the housing and engages a portion of the valve plug to retain the valve plug in the housing.

Abstract: A flow control device is disclosed. The flow control device comprises a pressure reducing valve. The pressure reducing valve comprises a valve body having at least an inlet port on a high side and an outlet port on a low side and having walls defining a regulating chamber, the outlet port in fluid communication with the regulating chamber. A diaphragm assembly is provided having a diaphragm and a stem for engaging the diaphragm. The stem has a base and a connecting arm. The diaphragm engages the main valve at a perimeter thereof so as to partially enclose the regulating chamber. A valve controlled opening cooperating with the connecting arm of the stem is located between the inlet port and the regulating chamber. The valve controlled opening is adapted to adjustably restrict flow of gas between the inlet port and the regulating chamber responsive to movement of the connecting arm.

Abstract: A compensating pressure regulator comprising a single stage regulating device for controlling the flow of compressed gas therethrough; and a compensating device for automatically adjusting transient pressure conditions to provide a substantially uniform gas pressure output by use of a pin like-piston having dual sources of pressure thereon. The compensating pressure regulator for use with bottled gas on portable tools.

Abstract: A hot air generator comprising a handle (12), an elongated nozzle (14), flame generating means (6), a venturi (4), a gas conduit (162) intended to bring a combustible gas into the elongated nozzle (14) and at the flame generating means (6), an air conduit (164) intended for bringing compressed air into the elongated nozzle (14) and downstream from the venturi; characterized in that the generator further comprises a servocontrolled pressure regulator (2) controlling a gas pressure (Pd.g) in the gas conduit (162) depending on an air pressure (Pd.a) in the air conduit (164).

Abstract: Diaphragm assemblies for use with fluid control devices are described. An example diaphragm assembly includes a body defining a plurality of chambers to be fluidly coupled to an outlet pressure of a fluid control device. Each of the chambers is spaced along a stem at least partially disposed in the chambers, and the stem is to move to control a flow of fluid through the fluid control device. Additionally, the example diaphragm assembly includes a first plurality of diaphragms, each of which is disposed in a corresponding one of the chambers, and each of which is coupled to the stem to move the stem in response to the outlet pressure of the fluid control device.

Abstract: Systems and methods for venting gas from a gas regulator in the event of overpressurization of the gas regulator are provided. A bonnet for a gas regulator that includes one or more apertures through which gas may vent. The bonnet may be made of a moldable synthetic plastic material, such as glass filled nylon.

Abstract: An example loading regulator having an internal relief valve apparatus includes a body having a loading diaphragm disposed between a first casing and a second casing. The first casing and a first side of the loading diaphragm define a first chamber and the second casing and a second side of the loading diaphragm define a second chamber. A relief valve assembly is coupled to the loading diaphragm. The relief valve assembly includes a relief valve seat having an aperture that forms a passageway to fluidly couple the first chamber and the second chamber and a relief valve plug movably coupled to the relief valve seat. The relief valve seat is to move relative to the relief valve plug to a bleed position to allow the flow of fluid between the first chamber and the second chamber in response to an outlet pressure substantially greater than a pressure at which the loading regulator enters a lock-up condition.

Abstract: Embodiments of the present invention are directed toward pressure controllers and calibrators for setting or measuring pressures in test devices. In one embodiment, the pressure controller contains a dual reference pressure controller. The dual reference pressure controller is operable to maintain two different pressures relative to a reference pressure. The first pressure being a relatively fixed amount greater than the reference pressure and the second pressure being a relatively fixed amount less than the reference pressure.

Abstract: A pressure reducing valve including a balanced valve cartridge. The balanced valve cartridge has a retainer including a central bore. A valve seat and a valve plug are disposed within the central bore and cooperate to open and close the valve. A cap closes one end of the central bore, the cap including a blind bore for receiving a portion of the valve plug. Downstream fluid pressure is transmitted into the blind bore through a hollow portion of the valve plug, thus balancing the valve plug within the retainer.

Abstract: A high pressure regulator for compressed gas weapons, and in particular for paintball markers, is situated inside a cylindrical regulator housing which is connected to a source of compressed gas. The cylindrical regulator housing comprises an inlet channel which is connected to a supply of high-pressure gas. A first regulator (H) comprises a first piston movably disposed within the regulator housing for regulating pressure in a first expansion chamber. A second regulator (D) comprises a second piston movably disposed within the regulator housing for regulating pressure in a second expansion chamber. The first piston and the second piston are arranged coaxially within the regulator housing. The high pressure regulator is suitable to be mounted in the foregrip of a paintball marker and reduce an inlet pressure of about 850 psi to a first pressure of about 250 psi and a second pressure of about 100 psi.

Abstract: A volume and pressure regulating device for an oxygen generating machine includes a body to combine a path assembly, a pressure valve assembly and a volume valve assembly within one body. The pressure valve assembly and the volume valve assembly are connected via the path assembly.

Abstract: Temperature-controlled pressure regulators are described. An example temperature-controlled pressure regulator described herein includes a regulator body having an inlet fluidly coupled to an outlet via a first passageway. A heat block is disposed within the regulator body and receives at least a portion of the first passageway. The heat block is to provide heat to the process fluid as the process fluid flows through the heat block via the first passageway, which separates the process fluid from the heat block.

Abstract: A fluid regulator that has excellent flow-rate-control response for not only pressure fluctuations at the primary side but also pressure fluctuations at the secondary side and that realizes highly accurate flow-rate control is provided.

Abstract: Regulators for regulating gas that is delivered in discrete charges from a tank that contains compressed gas to a paintball gun, marker, or other application that utilizes or is activated by pressure controlled discrete charges of gas. The regulator has holding, discharge, and fill configurations, controlled by the movement of a piston member in a pressurized chamber, and the activation of a poppet valve on the discharge of the system. One or two low side pressure relief members are provided to prevent the over-pressurization of the pressurized chamber. An externally threaded sleeve member is non-rotatably, but axially slidably received on a distal portion of the body of the regulator so that the sleeve member and distal portion may be axially slidably disengaged, and the regulator can be rotationally positioned so that the pressure gauge is easily viewed by an operator.

Abstract: An improved normally open (NO) gas pressure regulator is provided. Preferably, the regulator is employed with a paintball marker and operates as a NO regulator yet automatically purges the retained pressure downstream of the regulator upon removal of the supply pressure. The gas pressure regulator of the present invention includes a pressure-controlled plunger inside the NO regulator that allows the regulated downstream gases to be purged from the system as the supply source is removed from the marker. Accordingly, since the downstream regulated gases are allowed to exit the system when the supply source is removed, the regulated gas pressure is released and the paintball marker is rendered inoperable and safe.

Abstract: A combination air regulator and sensor assembly includes a head including a first chamber having an inlet and an outlet. A regulator dome including a second chamber is linked with the first chamber through a bore. The second chamber includes at least one outlet. A valve assembly is housed within the bore and moveable between closed and open positions sealing and allowing flow in the bore. A first diaphragm is positioned in the second chamber and linked with the valve assembly. The valve assembly moves in response to a pressure applied to the first diaphragm. A spring contacts the first diaphragm and applies a biasing force to the first diaphragm. A sensor dome including a third chamber is linked with the outlet of the second chamber. The sensor chamber includes a discharge outlet. A second diaphragm is positioned in the sensor chamber.

Abstract: A compressed gas regulator of a piston type is disclosed in which a regulator is configured with an input valve situated entirely inside a compressed air canister, which regulator is then attached to a paintball gun, marker or other device for providing discrete charges of gas at a predetermined pressure to the attached device. The overall size and weight of the regulator are minimized, which allows increased capabilities to the user. A regulator overpressurization port vents behind a conventional safety gauge for safety purposes. Fill, gage, and canister overpressurization rupture ports are interconnected with a fill channel that extends from the canister to the ports without intersecting or interfering with the regulating components within the regulator. The input valve seat face is surrounded by a shallow generally conical surface within an input plenum. The shallow generally conical surface extends at approximately 5 to 15 degrees.

Abstract: An annular mating portion extends from a fastening surface of a fastening nut. The mating portion has an inner diameter set to be substantially equal to an outer diameter of the portion of a piston in which an accommodating groove is formed. In a state in which the mating portion is inserted into the accommodating groove, and an inner circumferential surface of the mating portion slides in contact with a circumferential wall of the accommodating groove, the fastening nut is mated with a threaded portion, and a lip seal is held between the mating portion and the accommodating groove. This fixes the lip seal to the piston.