Abstract: A thermostatic valve includes a housing having a fluid inlet, a first outlet and a second outlet, a flap that is movable between a closed position, in which the flap closes the first outlet, and an open position, in which the flap opens the first outlet. The valve also includes a thermostatic actuator with an actuating rod connected to the flap and a capsule containing a thermally expanding material, and a heating element. The capsule has an internal portion, which extends inside the housing so as to be immersed in the fluid flowing between the inlet and the second outlet of the housing, and an external portion, which extends outside the housing. The heating element is arranged outside the housing and outside the capsule in order to heat the external portion.

Abstract: A thermostatic valve includes a housing having a fluid inlet, a first outlet and a second outlet, a flap that is movable between a closed position, in which the flap closes the first outlet, and an open position, in which the flap opens the first outlet. The valve also includes a thermostatic actuator with an actuating rod connected to the flap and a capsule containing a thermally expanding material, and a heating element. The capsule has an internal portion, which extends inside the housing so as to be immersed in the fluid flowing between the inlet and the second outlet of the housing, and an external portion, which extends outside the housing. The heating element is arranged outside the housing and outside the capsule in order to heat the external portion.

Abstract: The valve includes a valve body that inwardly defines a passage for circulation of a fluid, a drive shaft, and a bearing to guide the rotation of the drive shaft. The bearing comprises a chamber surrounding a segment of the drive shaft and a plurality of balls filling the chamber. The balls are free inside the chamber, and the chamber is completely filled with balls. The balls are in contact with the drive shaft along all or part of the segment.

Abstract: A needle shell is inserted through skin with a needle insert within the needle shell occluding an insertion end of the needle shell. The needle insert is withdrawn from the needle shell and an implant tube is inserted into the needle shell and below the skin, wherein the implant tube is slid within the needle shell while the needle shell is below the surface of the tissue. Interior surfaces of the implant tube contact and guide sliding movement of the implant. An implant insertion rod is inserted into the needle shell to implant an implant below the skin.

Abstract: A system for controlling fluid flow includes a fluid inlet operable to receive a fluid flow, a fluid outlet operable to output the fluid flow, a diaphragm seat, a diaphragm operable to restrict the fluid flow between the fluid inlet and the fluid outlet by moving between an open position where the first diaphragm does not contact the diaphragm seat to a closed position where the diaphragm contacts the diaphragm seat, a spring operable to move the first diaphragm between the open position and the closed position, and a pressurized air inlet operable to receive pressurized air to move the first diaphragm between the open position and the closed position.

Abstract: A folding bellows for protecting an interior of the folding bellows effectively from environmental influences and managing pressure changes in the interior. The folding bellows having a gas-tight casing including a plurality of folds in an axial direction. Opposed front faces adjoining the casing. The front faces closed in a gas-tight manner. The casing having a wide region and a narrow region each formed of a plurality of folds with the outer cross-sectional surface of the folds in the wide region being larger than those in the narrow region. The folding bellows in one embodiment used with a motor vehicle subassembly.

Abstract: A capacity control valve includes: a pressure-sensitive body positioned in a third valve chamber; an adapter provided on the free end of the pressure sensitive body having a circular seating surface; a third valve part that moves integrally with a valve element in the third valve chamber and has a circular engagement surface that opens/closes intake-side passages by engaging with and separating from the seating surface of the adapter. The valve element is located between the first valve chamber and the second valve chamber, and has an outer circumferential face part slidably movable relative to an inner circumferential face of the valve body, with plural threads of screw grooves are formed on the outer circumferential face part.

Abstract: A component feed nozzle includes a housing, which has a component inlet and a component outlet, a piston-shaped closing body, which is slidably supported in the housing and which can be moved back and forth axially. The component outlet is closed by the front end of the closing body in a first position and the component outlet is released or opened in a second position. The component feed nozzle has a membrane seal, which is fastened to the rear end of the closing body and to the housing in such a way that the closing body is completely on one face of the membrane seal. The housing and/or the closing body are designed in such a way that the component reaches all surfaces of the closing body and thus the component pressure is applied to the complete effective surface of the membrane.

Abstract: A valve for controlling fluid flow from an inlet of a pipe fitting to at least one outlet of the pipe fitting at an angle to the inlet. The pipe fitting includes an inner collapsible bellows fixed at a position opposite the inlet. The bellows has a support annulus at the other end adjacent the inlet, whereby, in a closed position, the bellows prevents fluid flow from the inlet to the at least one outlet as the fluid is trapped within the bellows. In an open position, the fluid can flow from the inlet to the at least one outlet when the bellows is collapsed.

Abstract: A non-pyrotechnic, normally-closed, zero-leak valve is a replacement for the pyrovalve used for both in-space and launch vehicle applications. The valve utilizes a magnetostrictive alloy for actuation, rather than pyrotechnic charges. The alloy, such as Terfenol-D, experiences magnetostriction, i.e. a gross elongation, when exposed to a magnetic field. This elongation fractures a parent metal seal, allowing fluid flow through the valve. The required magnetic field is generated by redundant coils that are isolated from the working fluid.

Abstract: A vacuum valve closes a flow path in a gas-tight manner using a linear movement and includes a closure member, a first sealing surface of the valve housing that encloses the opening, and a corresponding second sealing surface of the closure member. In the closed position, the second sealing surface is in sealing contact with the first sealing surface. In the region between the opening and the first sealing surface, the valve housing includes a first sloped surface that encloses the opening, and the closure member includes a corresponding, parallel second sloped surface. The sloped surfaces, which have a sloping angle between 3 and 15 degrees relative to the geometric adjustment axis, are located such that, in the closed position of the closure member, the second sloped surface is arranged in a parallel position opposite the first sloped surface at a distance of 0 and 0.6 mm.

Abstract: A valve having a valve body with a valve cavity that receives an axially extensible member, for example, a bellows. An adapter has a diameter that is less than the diameter of the valve cavity and greater than the diameter of the extensible member, so that the adapter is disposed between the valve body and the extensible member. The adapter forms a valve body compression seal and a compression seal for the extensible member. Use of the adapter allows a common valve body to be used with different sized bellows of different lengths and diameters as needed, as well as facilitates easy installation and replacement of the bellows.

Abstract: A valve includes a plug mounted to a lower end of a valve rod for opening or closing a fluid passage in the body. The valve rod extends through a cap and a stretchable jacket. The stretchable jacket includes first and second ends and a deformation section between the first and second ends. The first end of the stretchable jacket is fixed to the cap. The second end of the stretchable jacket is fixed to the valve rod. A stop is located at the deformation section, dividing the stretchable jacket into first and second stretchable sections. A pull rod is fixed to the valve rod or the cap and slideable relative to the stop. First and second positioning members are mounted on the pull rod to limit travel of the pull rod by contacting with the stop, avoiding over stretching and undesired compression of the first or second stretchable section.

Abstract: Valves for regulating the flow of fluids where high containment of the fluid is required for environmental and/or regulatory compliance.

Abstract: A stroke translator or an injector having a solid-state actuator for generating a stroke and a hydraulic system for the hydraulic transmission of the stroke of the solid-state actuator to a control element such as a jet needle of a valve. The hydraulic system has hydraulic volumes hermetically sealed to the outside by metal bellows and constitute a hydraulic bearing with compensation for play. The advantages over known hydraulic levers are such that a complete metal seal is provided, and that a lower-wear design can be realized. Furthermore, a modular structure can be produced.

Abstract: The invention discloses a valve including a valve body with a valve inlet and a valve outlet. The valve body is joined to a bellows between the valve inlet and the valve outlet, the bellows having an annular side wall formed in a concertina formation with inner and outer corners wherein the side wall has a non-constant thickness along its length, the side wall being thicker at the outer corners and thinner at the inner corners. The bellows further has an annular mounting base for attachment to the valve body. The valve body has an annular flange from which extends an upstanding collar, wherein the mounting base is clamped between the valve body and the collar. The mounting base has a width being wider than a gap formed between the valve body and the collar so that the mounting base is compressed when clamped between the valve body and the collar.

Abstract: A gas control unit for a boiler includes a hollow housing; a solenoid; a rod; opening and shutting means that is disposed at the lower end of the rod to open and shut a gas outlet; and a spring between the housing and the opening and shutting means so as to elastically urge it downward. A coupling member is formed at the lower end of the rod and a coupling groove into which the coupling member is inserted is formed in the opening and shutting means so as to allow movement. The opening and shutting means is coupled to the rod through the use of the coupling member and the coupling groove, the opening and shutting means can move within a predetermined range about the coupling member with an application of an external force.

Abstract: A bellows is disposed to separate a main flow path that is opened or closed by a valve member coming into contact with or moving away from a valve seat from a driving part for driving the valve member via a rod so as to surround the rod. The bellows is formed by providing ring-shaped valley portions swelling inward of a metal pipe and ring-shaped peak portions swelling outward of the metal pipe alternately and continuously in a peripheral wall of the metal pipe in the axial direction of the metal pipe. Valley R/peak R, which is the ratio of valley R to peak R, is in the range of 1.15 to 1.70, where valley R is the radius of curvature of the valley portions in cross section, and peak R is the radius of curvature of the peak portions in cross section.

Abstract: The present invention provides a flow-rate control valve that allows for manufacturing cost reduction and has a compact size with improved ease of maintenance. The flow-rate control valve includes a lower casing provided with a channel that leads a liquid and a fluid and with a valve seat, a valve body that controls, in conjunction with the valve seat, the flow rate of the liquid and the fluid that pass through the channel, a reciprocating drive part that moves the valve body closer to or away from the valve seat, and an upper casing that houses the reciprocating drive part.

Abstract: Provided is a valve for vacuum process, including: a first valve body having an inlet port and an outlet port; a sealing unit configured to move forward to and backward from the inlet port so as to have a closed position and an open position; a shaft covered with a bellows, and configured to move the sealing unit between the closed position and the open position; a cover for shielding the bellows from corrosive gas when the sealing unit is in the open position; and a cover guide unit configured to guide the cover to move along the shaft.

Abstract: The invention relates to a valve device that is used in oil and gas wells. The valve device has an external housing (1), where at least one inlet (4) in the housing (1) is connected to an outlet (5) through a longitudinal bore in the housing longitudinal direction. Between the valve device's inlet and outlet there is mounted a valve seat (2) in the bore, where a valve body (3) shuts off the connection between the inlet and outlet. The valve body's position is controlled by a support (20), connected with a pressure-sensitive bellows device (6) comprising an upper and a lower bellows element (7, 71). When the lower bellows element is compressed in the valve device's axial direction, the compression will cause the two bellows elements'impact elements to be moved relative each other in order to lift the valve body out of abutment with the valve seat.

Abstract: A bellows seal assembly and bellows valve equipped therewith. The bellows seal assembly includes an internal bellows, an external bellows, a hollow upper bellows seat, a first hollow lower bellows seat, and a second hollow lower bellows seat. One end of the internal bellows is fixed to the upper bellows seat and the other end is fixed to the second lower bellows seat. One end of the external bellows is fixed to the upper bellows seat and the other end is fixed to the first lower bellows seat. The external bellows is sheathed around the internal bellows. The first lower bellows seat is sheathed around the second lower bellows seat. The bellows valve includes the bellows seal assembly.

Abstract: A double pipe apparatus that includes an outer pipe and an inner pipe inserted into the outer pipe, and regulates a flow of a gas flowing through the double pipe apparatus. The double pipe apparatus includes a flow regulating valve, a valve stem which which penetrates the outer pipe and the inner pipe, and fluid leakage preventing parts including a bellows which is provided between the outer pipe and the inner pipe and which prevents the gas from leaking outside the outer pipe. One end of the bellows is attached to an inner wall of the outer pipe, and the other end of the bellows is attached to a flange formed on the valve stem, so that the gas flowing through the inner pipe is prevented from leaking outside the outer pipe.

Abstract: A valve stem is journaled in a journaling portion of a valve box in an upwardly and downwardly movable manner; a packing is interposed between the journaling portion and the valve stem; a packing gland is arranged above the packing; a yoke sleeve is provided above the packing gland; and a valve seat in the valve box is opened and closed with a valve element provided at the lower end of the valve stem by rotating a handle fitted into the yoke sleeve to move the valve stem upward and downward. A protective tube formed integrally with the packing gland is provided between the packing gland and the yoke sleeve around the valve stem. A guide projection with which the inner periphery of the upper end of the protective tube comes into contact is provided on the lower surface of the yoke sleeve.

Abstract: A fluid injection valve having an inlet which is set up to receive fluid from a supply line and is connected to a chamber, a fluid outlet which is connected to the chamber, is set up to allow fluid to flow out of the fluid injection valve and has a valve arrangement having a valve seat and a valve element, wherein the valve element is set up to perform opening and closing movements relative to the valve seat, a linear actuator which is set up to move the valve element relative to the valve seat, and a spring arrangement which exerts on the valve element a force which is dependent on the fluid pressure prevailing in the chamber.

Abstract: A heater built-in valve usable even under a high-temperature condition beyond 200° C. is provided. Piston driving means 7 has an upper compressed-air introducing chamber 24 for moving a piston 6 downward, and a lower compressed-air introducing chamber 25 for moving the piston 6 upward. Piston sealing means 8 has an upper bellows 29 that seals the upper compressed-air introducing chamber 24, and a lower bellows 30 that seals the lower compressed air introducing chamber 25.

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: A bellows seal assembly and bellows valve equipped therewith. The bellows seal assembly includes an internal bellows, an external bellows, a hollow upper bellows seat, a first hollow lower bellows seat, and a second hollow lower bellows seat. One end of the internal bellows is fixed to the upper bellows seat and the other end is fixed to the second lower bellows seat. One end of the external bellows is fixed to the upper bellows seat and the other end is fixed to the first lower bellows seat. The external bellows is sheathed around the internal bellows. The first lower bellows seat is sheathed around the second lower bellows seat. The bellows valve includes the bellows seal assembly.

Abstract: A suck-back valve having an open/close valve with a suck-back function is provided. The suck-back valve includes a suck-back chamber formed in a valve internal channel of the open/close valve, a piston shaft portion and an open/close pressuring member to apply pressure to a valve piece, bellows that accommodate the piston shaft portion inside and that are connected to the open/close pressuring member at one end and are supported by a casing at the other end, wherein a two-step operation is performed at the time of a closing operation of the valve piece, including a valve closing operation step in which the piston shaft portion moves to the fully closed position of the valve piece, and a suck-back operation step in which the piston shaft portion and the open/close pressuring member further move from the fully closed position of the valve piece to increase the volume of the suck-back chamber.

Abstract: A valve seal has a sealing lip and a compressible portion. The valve seal is utilized to seal a valve guide and a stem. The valve guide has a height within a predetermined range of heights and the sealing lip sealingly engages the stem. The compressible portion has at least two articulating portions with a hinge portion between the two articulating portions. The compressible portion sealingly engages the valve guide and articulates to accept the valve guide without substantially deforming the lip or interfering with the stem.

Abstract: An isolation valve includes a shield that surrounds and protects the valve closure actuator components from exposure to corrosive fluids that flow through the valve when the valve is open.

Abstract: An actuator assembly for actuating a valve includes an extensible bellow having an open end and a closed end, a stem operable to contact the closed end and to actuate a stopper mechanism, and a driver configured to move the bellow. The movement of the bellow effects movement of the stem to actuate the valve. In one embodiment, the driver acts to compress the bellow, the compression causing movement of the stem to open the valve. The bellow may be hermetically sealed to the valve housing, thereby allowing a higher range of fluid pressures.

Abstract: A control valve having an external valve trim adjustor is provided. The control valve comprises a valve shaft comprising a contact member extending in a direction transverse to the valve shaft, a stationary valve cap adapted to receive the valve shaft, an adjustment member coupled to the valve cap, and a stop plate coupled to the contact member and threadedly coupled to the adjustment member, the stop plate positioned at least partially between the adjustment member and the contact member and adapted to position the contact member away from the valve cap in response to manipulation of the adjustment member.

Abstract: An apparatus and method for an aseptic fluidic interface between bioprocess systems is provided. The apparatus includes an inlet valve, adapted for automatic control, that is coupled to a biofluid source site. A sampling conduit extends from the inlet valve to an outlet valve. The outlet valve is adapted for automatic control and is coupled to a biofluid process site. A trap is at the sampling conduit. A waste valve, adapted for automatic control, is located at a waste conduit extending from the sampling conduit to a waste site. Also included is a wash fluid source that is coupled to at least one of the inlet or outlet valves. In the method, the sample is automatically directed to the biofluid process site by opening the outlet valve, and closing the waste valve. Also included is isolating the biofluid sites by closing the inlet and outlet valves, and opening the waste valve to drain biofluid from the trap to the waste site.

Abstract: In a flow amount control valve, a rod is inserted through the interior of a housing, and first and second connecting members are connected coaxially to both ends of the rod. A first bellows and a second bellows, each having a bellows portion, are provided on the rod, for preventing leakage of fluid that is introduced into the interior of the housing. In addition, the first bellows and the second bellows are expanded and contracted by displacement of the rod along the axial direction, which is caused by driving an actuator, such that a valve element of the rod approaches and separates with respect to a valve seat, and a gap between the valve element and the valve seat changes so that a flow amount of the fluid is controlled.

Abstract: To provide a vacuum valve with an improved endurance of a bellows, a vacuum valve comprises: a valve section including a first port, a second port, a valve seat provided between the first and second ports, and a valve element movable into or out of contact with the valve seat; an actuator section including an orifice through which an operating fluid is supplied to the actuator section, and a piston coupled to the valve element, the piston being allowed to operate according to changes of pressure of the operating fluid to apply a driving force to the valve section; and a bellows which can be contracted and elongated as the valve element vertically moves upward and downward. The orifice is designed to have an effective sectional area determined so that an operating speed of the valve element and the piston is controlled to a predetermined speed for preventing damage of the bellows.

Abstract: In a vacuum valve composed of a main valve portion that opens and closes a vale seat in a flow path connecting two ports by a valve member, and an operating portion that performs an opening and closing operation for the valve member, the housing of the main valve portion is assembled by joining the two port members with a cylindrically shaped housing main body formed by a squeezing process for a plate material made of metal, or a ring-shaped material made of the metal. In an end portion of the housing, a flange-shaped attaching portion that is bent inward is formed. The operating portion is attached onto the attaching portion via a ring-shaped supporting seat member. A sealing member is sandwiched between a ring-shaped supporting plate and the attaching portion. Both ends of a bellows are respectively connected to the supporting plate and the valve member.

Abstract: The high vacuum valve includes a valve housing having a valve flow channel provided in an interior thereof, two ports connected to the valve housing so as to be arranged perpendicular relative to each other, and capable of being communicated with each other through the valve flow channel, a valve member housed in the valve flow channel for opening and closing the valve flow channel, a valve shaft received in the valve flow channel for causing the valve member to perform opening/closing operations, and an assembly comprising a tubular member and a welded bellows and hermetically surrounding a periphery of the valve shaft, the assembly being fixed at one end portion thereof to a rear face of the valve member and fixed at the other end portion thereof to a portion of the interior of the valve housing which is opposed to the rear face of the valve member.

Abstract: A valve includes a generally elongate pintle; a spacer having a rounded surface that bears against the pintle; a bulbous tip fixed to the spacer; and a hollow, generally cylindrical collar fixed to the pintle, the collar enclosing the spacer and the tip and including an opening through which a portion of the tip extends, the opening in the collar and interior of the collar being of a size such that the tip floats therein.

Abstract: A high pressure storage and delivery system having a fail-safe vacuum actuated valve is provided. In particular, through the innovative design of the vacuum actuated check valve, the system can accommodate up to three times the volume of product in similar size cylinders.

Abstract: A retaining cylinder is threadedly engaged with a fixed cylinder of a flow rate control valve, by means of a screw section formed on an outer circumferential surface. A fence cover, which is capable of expanding and contracting in the axial direction, is installed between the fixed cylinder and a float rod supported by the retaining cylinder. An upper seal member is provided on the float rod, on the upper side thereof with respect to a valve plug. A lower seal member is provided on the lower side thereof with respect to the valve plug. The upper seal member and the lower seal member have substantially identical diameters. The float rod is displaced under an energizing action of a stepping motor. The flow rate of a fluid is controlled depending on a distance of the valve plug with respect to a valve seat.

Abstract: A Wide-body Valve Having an Internalized Actuator is disclosed. The preferred valve provides exceptional conductance while also providing a compact valve and actuator package. The valve incorporates a geometry wherein the internal diameter of the valve is approximately 180% of the diameter of the valve's port. Furthermore, the stroke of the valve is preferably 30% or more of port diameter. Also, the valve actuator housing is designed to cooperate with the valve body housing such that the actuator housing is encapsulated within the valve body housing such that the valve part count and valve part volume is reduced over conventional valves.

Abstract: An actuator assembly for actuating a valve includes an extensible bellow having an open end and a closed end, a stem operable to contact the closed end and to actuate a stopper mechanism, and a driver configured to move the bellow. The movement of the bellow effects movement of the stem to actuate the valve. In one embodiment, the driver acts to compress the bellow, the compression causing movement of the stem to open the valve. The bellow may be hermetically sealed to the valve housing, thereby allowing a higher range of fluid pressures.

Abstract: The invention relates to a seal to be used as a valve stem seal in a valve for controlling flows containing solid material such as slurry flows with an actuator. The seal is positioned outside of the valve body so that the inside of the seal and the valve body form an essentially closed space for the flow to be controlled.

Abstract: A fuel injection valve includes a valve body having a valve seat, a valve element adapted to sit on and leave a valve seat, a nozzle hole for the injection of fuel, and an electromagnetic drive section. A holding member surrounds and holds, on one end side thereof, at least a partial area of an opposite-to-nozzle-hole-side end face portion of the valve element. The holding member surrounds and holds, on an opposite end side thereof, a predetermined surface area of a constant position holding portion without being influenced by the pressure of fuel flowing through a fuel passage of the valve body and irrespective of movement of the valve element. An internal area of the holding member is shut off so as not to be influenced by the pressure of fuel present around the internal area.

Abstract: An idle air control valve for a vehicle includes a housing (21), a motor (32) disposed in the housing, a shaft (29) associated with the motor, and a bellows assembly (30) including a bellows structure (10) having a first end defining a base (14), a second, opened end (16), and a bellows (18) between the first and second ends. An annular rim member (28) is associated with the second opened end. A pintle (24) has surfaces defining an annular groove (26) therein. The annular rim member (28) is received, in press-fit engagement, in the annular groove (26). The base (14) is in press-fit engagement with a recess (22) in the housing and the pintle (24) is coupled with an end of the shaft, such that the bellows structure together with the pintle surround the shaft and provide a barrier substantially preventing contaminants from entering the motor.

Abstract: In a flow amount control valve, a rod is inserted through the interior of a housing, and first and second connecting members are connected coaxially to both ends of the rod. A first bellows and a second bellows, each having a bellows portion, are provided on the rod, for preventing leakage of fluid that is introduced into the interior of the housing. In addition, the first bellows and the second bellows are expanded and contracted by displacement of the rod along the axial direction, which is caused by driving an actuator, such that a valve element of the rod approaches and separates with respect to a valve seat, and a gap between the valve element and the valve seat changes so that a flow amount of the fluid is controlled.

Abstract: A closing device for a vacuum user system or vacuum toilet system of an aircraft that makes it possible to quickly open and close a pipe connection piece in a vacuum user system or in a vacuum toilet system of an aircraft. The closing device comprises a cover; a closing element that can be inserted into the pipe connection piece and is connected to the cover by a spacer and is designed such that it substantially fully covers a cross section of the pipe connection piece; a sealing bellows located between the cover and the closing element and that at least partly encloses the spacer, wherein the sealing bellows comprises a sealing face; and an element that is movable in relation to the cover, which element is movable from a first position to a second position, wherein the movable element engages the sealing bellows such that the sealing face of the sealing bellows in the second position has a greater extension in a plane across the spacer than it does in the first position.

Abstract: The high vacuum valve includes a valve housing having a valve flow channel provided in an interior thereof, two ports connected to the valve housing so as to be arranged perpendicular relative to each other, and capable of being communicated with each other through the valve flow channel, a valve member housed in the valve flow channel for opening and closing the valve flow channel, a valve shaft received in the valve flow channel for causing the valve member to perform opening/closing operations, and an assembly comprising a tubular member and a welded bellows and hermetically surrounding a periphery of the valve shaft, the assembly being fixed at one end portion thereof to a rear face of the valve member and fixed at the other end portion thereof to a portion of the interior of the valve housing which is opposed to the rear face of the valve member.

Abstract: To provide a vacuum valve with an improved endurance of a bellows, a vacuum valve comprises: a valve section including a first port, a second port, a valve seat provided between the first and second ports, and a valve element movable into or out of contact with the valve seat; an actuator section including an orifice through which an operating fluid is supplied to the actuator section, and a piston coupled to the valve element, the piston being allowed to operate according to changes of pressure of the operating fluid to apply a driving force to the valve section; and a bellows which can be contracted and elongated as the valve element vertically moves upward and downward. The orifice is designed to have an effective sectional area determined so that an operating speed of the valve element and the piston is controlled to a predetermined speed for preventing damage of the bellows.