Abstract: A pressure relief valve includes a lever plate, a first spring, a fitting, and a guide assembly. The fitting has a first side, a second side, and a flange having a rounded end and includes a surface with which a first end of the first spring contacts. The guide assembly has two sides, two concavities, and at least a portion of the guide assembly extends through the opening of the lever plate, the first concavity is formed on the first side of the guide assembly and contacts the fitting flange rounded end, and the second concavity is aligned coaxially with the first concavity. A rounded end of a rod of the diaphragm assembly contacts the second concavity. The second spring is adapted to supply a second force against the diaphragm assembly to move the lever plate in a second direction that is substantially opposite the first direction.

Abstract: A gas cylinder valve 2 is able to be opened by application of a pilot gas pressure. In certain embodiments the gas cylinder valve 2 is usable with a yoke 8 for engaging with a valve assembly of a gas cylinder 1, the yoke comprising a pilot gas passage 28 able to connect a pilot gas chamber 37 in the cylinder valve assembly to a source of pressurised pilot gas and the cylinder gas port of the gas cylinder valve to an external cylinder gas passage. The valve and yoke enable the tamper-resistance of a gas cylinder to be improved.

Abstract: A control valve capable of performing capacity control independent of the pressure of operation fluid and according to preset conditions. The control valve opens and closes a first poppet valve and a second poppet valve by a solenoid section where a solenoid rod is moved according to the magnitude of an electric current. In the control device, the following pressure-receiving areas are set to be substantially equal to each other: the first effective pressure-receiving area of a first pressure-sensing spring device forming the first poppet valve and the second poppet valve, the second effective pressure-receiving area of a second pressure-sensing spring device, the first pressure-receiving area on the inner side of a portion where a first valve seat surface and a first valve section surface are in contact with each other, and the second pressure-receiving area on the inner side of a portion where a second valve seat surface and a second valve section surface are in contact with each other.

Abstract: An air compressor utilizing an electronic control system. A pneumatically controlled regulator is provided for controlling output pressure for an air compressor. Digital gauges are provided on the air compressor to replace conventional mechanical gauges. A variable speed motor is used, which in turn varies the speed of the pump. Tools are provided for an air compressor that are capable of transmitting a signal to the air compressor indicating a desired pressure and/or motor speed at which the air compressor is to operate.

Abstract: Multi-stage fluid regulators are described. An example fluid regulator includes a regulator body having an inlet in fluid communication with a source of pressurized fluid. A first fluid valve is disposed within the regulator body and coupled to the inlet to regulate a pressure of the pressurized fluid at the inlet. A second fluid valve is disposed within the regulator body and coupled to the inlet and, via a passageway, to the first fluid valve. The second fluid valve is to cause a fluid pressure in the passageway to be regulated to a predetermined portion of the pressure of the pressurized fluid at the inlet.

Abstract: The dunnage airbag inflation circuit of this invention includes a pilot valve that is controlled by a pressure sensing line in communication with the dunnage bag, and an arrangement of other valves to allow the dunnage bag to inflate up to a certain preset pressure. The pressure sensing line controls pilot air to various valves and ultimately to the main pilot valve allowing airflow to the dunnage bag until the dunnage bag reaches a certain preset pressure. The inflation circuit also includes (i) a safety pressure valve to stop airflow to the dunnage bag if for some reason the dunnage bag continues to be inflated past the preset pressure, and (ii) a stop valve that allows an operator to manually override the pressure valve and stop the airflow to the dunnage bag.

Abstract: A pressure limiting valve has a control element (10) which can be acted on in an opening direction, against a first control face, by a pressure which is to be limited, and which can be acted on in a closing direction by a spring (16) and, against a second control face, by a control pressure prevailing in a control pressure space (14). The pressure prevailing in the control pressure space can be limited by means of a pilot control valve (21). A control fluid can be supplied to the control pressure space through the control element via a control fluid nozzle (48). Upstream of the first control face, a plate (38) is held on the control element. Formed between the plate and the first control face is a gap with a predefined gap dimension. Said gap is situated upstream of the control fluid nozzle.

Abstract: The invention relates to a valve, in particular, a proportional pressure relief valve, comprising an electrically controlled solenoid system (10) for the control of an operating part (12,12a) which cooperates with a valve element (26), running longitudinally inside a valve housing (24) which releases a fluid transport connection path, between a fluid inlet (32) and a fluid outlet (34), in the open position thereof, and which blocks the through path in the closed position thereof, whereby an energy store, preferably in the form of a compression spring (58) is arranged between the operating piece (12,12a) and valve element (26) in a free gap between the two, which tends to hold the valve element (26) in the direction of the closed position thereof and the operating piece (12a) is embodied as a type of guide piston (70) which has a longitudinal guide for the valve element (26).

Abstract: In a magnet system for MRI imaging comprising a superconducting magnet (10) mounted within a cryogen vessel (12), apparatus is provided for controlling egress of cryogen gas from the cryogen vessel. The apparatus comprises a controlled valve (42) linking the interior of the cryogen vessel to a gas exit path; and a controller (30) arranged to control the valve. The valve is arranged such that a gas pressure in the cryogen vessel exceeding a gas pressure in the gas exit path acts on the valve to open the valve and allow venting of cryogen gas. The valve is also arranged such that a gas pressure in the cryogen vessel inferior to a gas pressure in the gas exit path acts on the valve to urge it closed, so restricting flow of gas into the cryogen vessel.

Abstract: A pilot-operated valve has a main poppet controlling fluid flow between inlet and outlet ports in response to pressure in a control chamber. Fluid flow through a pilot passage, linking the control chamber and the outlet port, moves an exhaust spool between first and second positions to control fluid flow through passages in the main poppet. The first position blocks flow between the control chamber and the outlet port and provides a path between the control chamber and the inlet port. In the second position, flow between the control chamber and the outlet port is enabled, and a second path, that is more restricted than the first path, is provided between the control chamber and the inlet port. When the valve closes, flow through the first path allows movement of the main poppet at a faster rate than during opening when flow occurs through the more restricted second path.

Abstract: What is disclosed is a pilot-controlled pressure feed valve comprising a main stage and a pilot control stage, wherein the main stage comprises a piston that is biased into a closed position. The piston is provided with a piston bore through which an input port may be connected with a rear-side spring chamber. To this piston bore a throttle valve means is associated which provides a comparatively small cross-section of flow for the control oil in the pressure limiting function of the pressure feed valve, and a comparatively large cross-section of flow in the anti-cavitation function.

Abstract: Provided is a pressure control valve including a movable part (1) which operates by a differential pressure, a first valve (3, 4, 5) for reducing a primary pressure to a secondary pressure, a second valve (10, 11) which operates to block a flow path between an inlet flow path (12) and an outlet flow path (8) for discharging the secondary pressure when the first valve operates to open the inlet flow path (12) for introducing a fluid having the primary pressure, and a transmission mechanism (2) which links the operation of the movable part with the operations of the first and the second valves, in which either one of the movable part and the first valve is separated from the transmission mechanism.

Abstract: A pressure regulator having a housing that defines a gas inlet, a gas outlet, and a reference pressure connector. A diaphragm is provided in the housing, where the diaphragm defines, at least in part, a reference pressure chamber. In some illustrative embodiments, the reference pressure connector fluidly references the reference pressure chamber to a first pressure via a first orifice, and to a second pressure via a second bleed orifice. A gas valve incorporating a pressure regulator is also disclosed.

Abstract: In a hydraulic control system for an automatic transmission, a valve element of an accumulator closes communication between a pressure switch circuit and a detection circuit when a hydraulic pressure applied to the detection circuit is lower than a predetermined hydraulic pressure, and opens communication between the pressure switch circuit and the detection circuit when the applied pressure is higher than or equal to the predetermined hydraulic pressure. A switching element opens communication between one end of the pressure switch circuit and an exhaust circuit when the other end of the pressure switch circuit does not communicate with the detection circuit, and closes communication between the one end and the exhaust circuit when the other end communicates with the detection circuit.

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 pilot operated pressure valve which limits the rate of pressure rise and substantially eliminates excessive system and tank pressure spikes. Because the pilot ball downstream of the damping orifice is held off the pilot seat in the normal starting condition by a pilot return spring, the main piston will open immediately when system pressure overcomes the low bias pressure of the main spring. A pilot pressure bypass port, which selectively deactivates the pilot chamber features, may also be included.

Abstract: A valve assembly includes a valve body, a primary valve, and a pilot valve. The valve body includes an inner surface that forms a chamber, a first inlet receiving fluid from a first source and having a port fluidly communicating with the chamber, a restriction orifice receiving fluid from the first source, a second inlet receiving fluid from a second source, a vent outlet line, and an outlet. The primary valve moves between an open position, in which the port and restriction orifice fluidly communicate with the outlet, and a closed position, in which the restriction orifice, but not the port, fluidly communicates with the outlet. The pilot valve moves in response to a differential pressure between the first and second sources, between a first position, in which the chamber fluidly communicates with the vent orifice, and a second position, in which the chamber fluidly communicates instead with the second source.

Abstract: Disclosed is a flow regulator, especially for insertion into a jet regulator in an outlet fixture, comprising an insertion member that is penetrated by at least one flow duct in an axial direction as well as a throttle element which forms a control gap along with the insertion member in order to allow a fluid to penetrate into the at least one flow duct. The aim of the invention is to create a flow regulator which allows for significantly greater durability during use while offering maximum ease of operation when fluid is discharged. Said aim is achieved by a flow regulator in which the throttle element is embodied as a dimensionally stable throttle cap that is supported in relation to the insertion member via an elastic spring element.

Abstract: A relief valve assembly (27) for use with first (15) and second (21) conduits, one communicating high pressure. The assembly comprises a housing (29,33) defining first (45) and second (47) ports, and a poppet seat (49). A poppet member (43) and the housing define a spring chamber (55), and a spring (39) is disposed to bias the poppet member toward the seat. The poppet member defines a shuttle cavity (51), a shuttle passage (53) communicating from the cavity to the spring chamber, and the poppet defining a seat (57), and a fluid passage (61P) communicating with the first port, and a seat (59), and a second fluid passage (63) communicating with the second port. A shuttle valve assembly (71,73,75) is provided, whereby the fluid pressure in whichever of the ports is at lower pressure is communicated to the spring chamber and adds to the force of the biasing spring.

Abstract: A pilot-operated pressure shut-off valve having a main control piston which, when an upper system limit pressure in the hydraulic system is reached, connects an inlet, via which pressure medium can be fed to a hydraulic system, to an outlet by taking up a first switching position and, when a lower system limit pressure is reached, separates from the outlet by taking up a second switching position. The pressure shut-off valve has a pilot valve arrangement by which the fluidic connection of a control space adjacent to the main control piston can be changed in order to control the main control piston, and which has a valve housing, with a first pilot piston and a second pilot piston accommodated within the first pilot piston for compact construction and capability to adjust the two pilot pistons mechanically completely independently of each other.

Abstract: Disclosed is a relief valve, in which a flow rate of hydraulic fluid is not greatly changed even when temperature is changed, and thus providing smooth operation and preventing foreign materials contained in the hydraulic fluid from being introduced into the relief valve. The relief valve is comprised of a sleeve provided with a high-pressure inlet and a tank fluid channel; a main poppet provided with an inflow fluid passage and a back pressure chamber; an annular fluid passage provided on a front end of the main poppet; a seat provided with a seat fluid channel communicating with the back pressure chamber; and a pilot poppet communicating the seat fluid channel with the tank fluid channel.

Abstract: A starter air valve assembly includes a valve body, a flow control valve, a rate control servo mechanism, and a valve actuator. The valve body defines a flow passage having at least an inlet port and an outlet port. The valve is disposed at least partially within the flow passage and is moveable between an open position and a closed position. The rate control servo mechanism is adapted to receive pressurized fluid and is configured, upon receipt of the pressurized fluid, to supply a controlled flow of the pressurized fluid. The valve actuator is coupled to the valve and is in fluid communication with the rate control servo to thereby receive the controlled flow of the pressurized fluid. The valve actuator is configured, upon receipt of the controlled flow of the pressurized fluid, to move the valve between the closed position and the open position at a substantially controlled rate.

Abstract: A gas pressure regulator has an inlet for connection to an upstream gas line for flow of gas into the regulator under pressure and an outlet for connection to a downstream gas line for flow of gas out of the regulator at a reduced pressure. A pilot mechanism delivers a desired pilot gas pressure through a pilot passage. A main valve mechanism regulates the flow of gas through a main flow passage connecting the inlet and outlet of the regulator. The regulator has a piston chamber, and a piston operatively connected to the main valve mechanism and movable in the piston chamber. The main valve mechanism has a passageway between the piston chamber and the pilot passage whereby the pilot gas pressure is adapted to move the piston and thereby position the main valve mechanism to regulate the gas pressure at the outlet of the regulator.

Abstract: An automatic inlet control mechanism and air compressor unit include a valve cavity and valve outlet. The valve cavity includes a valve control chamber and valve inlet chamber. A valve piston assembly is positioned between the valve control chamber and the valve inlet chamber to prevent the flow of air between therebetween. The valve outlet allows air to flow from the valve inlet chamber into the compressor unit. The valve piston assembly prevents air from flowing from the valve inlet chamber to the valve outlet when the compressor unit is not drawing air. A vent passageway allows air to flow between the valve control chamber and the compression cylinder inlet when compression is begun at the start-up of the compressor unit or at the loading of the idling compressor unit. A vent orifice restricts the flow of air from the valve control chamber to the compression cylinder inlet.

Abstract: A starter air valve assembly includes a valve body, a flow control valve, a rate control servo mechanism, and a valve actuator. The valve body defines a flow passage having at least an inlet port and an outlet port. The valve is disposed at least partially within the flow passage and is moveable between an open position and a closed position. The rate control servo mechanism is adapted to receive pressurized fluid and is configured, upon receipt thereof, to supply a controlled flow of the pressurized fluid. The valve actuator is coupled to the valve and is in fluid communication with the rate control servo to thereby receive the controlled flow of the pressurized fluid. The valve actuator is configured, upon receipt of the controlled flow of the pressurized fluid, to move the valve between the closed position and the open position at a substantially controlled rate.

Abstract: A protection system for a pipeline comprises a hydraulically actuated valve operable to switchably prevent a flow of fluid from a first section of the pipeline to a second section of the pipeline, a hydraulic fluid source for supplying hydraulic fluid to said hydraulically actuated valve to enable actuation thereof, a vent for venting hydraulic fluid from the hydraulically actuated valve, the hydraulically actuated valve being connected to the vent via a differential pressure valve to control venting of the hydraulically actuated valve, a pressure transfer barrier with a first port connected to the first section of the pipeline and a second port connected to said differential pressure valve, said differential pressure valve being supplied with hydraulic fluid at a reference pressure.

Abstract: Disclosed is a pilot operated relief valve, in which a balance system is provided to offset a tank pressure exerted on a piston, so that a setting pressure of a pilot poppet is not changed even when the tank pressure is changed, and thus a function of the relief valve can be stably performed. The pilot operated relief valve is comprised of a sleeve, a main poppet provided to be movable in the sleeve, a seat provided in the sleeve, a housing connected to a rear end of the sleeve, a pilot poppet provided to be movable in the housing, a piston moved by a pilot signal pressure, and the balance system offsetting the tank pressure exerted on the piston.

Abstract: The internally piloted dome loaded pressure reducing regulator includes a regulator body with a main valve portion and a pilot valve portion. The inlet is fluidly connected to the main valve bore which in turn is connected to the pilot valve bore. Each of the pilot and main valve members are spring urged to a closed position while the pilot valve is moved to an open position by a diaphragm when there is a decrease of pressure in the pilot chamber. A continuous fluid connection is provided from the pilot chamber, including through the main valve member, to a control chamber portion below a piston which is moved under pressure to open the main valve member. The piston has a bleed hole bottom chamber portion to the top control portion which in turn is fluidly connected to the outlet.

Abstract: According to one aspect of the disclosure, the present invention provides methods and arrangements for controlling supply process gas to a process chamber for use in the manufacturing industry. Methods include controlling the operation of a valve coupled to the supply process gas line in a way such that pressure bursts in the process chamber due to the operation of the valve are reduced, or even eliminated.

Abstract: The fitting, in particular a safety valve, operates according to the relief principle or according to the loading principle. The fitting is opened and closed by a plurality of control parts. The control parts are connected in series in the control line of the fitting and are each actuated by a control valve. The control parts open the fitting only when all the control parts are in a position which opens the fitting. The fitting closes as soon as even only one of the control parts is in a position which closes the fitting.

Abstract: In order to safely close a shut-off device (2) used in a gas supply line (1) in the case of danger, the closing part of said shut-off device is coupled with a pneumatic working cylinder (4) whose actuating piston (3) is maintained in the respective open position of the shut-off device (2) by the accessory pressure of CO2 liquid gas cartridge (5) and against the force of a lock spring (6). Under emergency conditions, a ventilating valve (8) which relieves the pressure form the actuating piston (3) is electronically triggered by a gas sensor (10) positioned in a sensor zone by the inactivation of a securing magnet and the shut-off device (2) is safety closed.

Abstract: There is described a demand valve for a breathing apparatus wherein a pilot jet of the demand valve is controlled by a pivoting lever resiliently held against a planar face in which the pilot jet is formed. The pilot jet is preferably formed in a land surface surrounded by a recessed area of the planar face, and opening of the pilot jet is effected by movement of a control projection mounted on the pivoting lever. The area of the control projection is preferably greater than the area of the land surface.

Abstract: The internally piloted dome loaded pressure reducing regulator includes a regulator body with a main valve portion and a pilot valve portion. The inlet is fluidly connected to the main valve bore which in turn is connected to the pilot valve bore. Each of the pilot and main valve members are spring urged to a closed position while the pilot valve is moved to an open position by a diaphragm when there is a decrease of pressure in the pilot chamber. A continuous fluid connection is provided from the pilot chamber, including through the main valve member, to a control chamber portion below a piston which is moved under pressure to open the main valve member. The piston has a bleed hole bottom chamber portion to the top control portion which in turn is fluidly connected to the outlet.

Abstract: An actuator system for a system valve exposable to a source of system pressure. A piston within a sensing vessel is caused to move longitudinally from a first position to a second position in response to a designated system pressure. A first piston stem carried by the piston is mechanically coupled to an actuator control valve, which is interposed in a fluid path between an actuator and a source of actuator pressure. Movement of the piston from its first to second position causes the coupled actuator control valve to block the fluid path linking the actuator and its pressure source, thereby causing a predetermined change in pressure at the actuator. As a result, the actuator shifts from its unactuated to its actuated state, thereby causing the system valve to shift from a first system valve position to a second system valve position.

Abstract: The fitting, in particular a safety valve, operates according to the relief principle or according to the loading principle. The fitting is opened and closed by a plurality of pilot parts. The pilot parts are connected in series in the control line of the fitting and are each actuated by a pilot valve. The pilot parts open the fitting only when all the pilot parts are in a position which opens the fitting. The fitting closes as soon as even only one of the pilot parts is in a position which closes the fitting.

Abstract: A flow regulator for a water pump, comprising a valve body, a control element, a tube, a spring, and a connecting pipe. The valve body is roughly shaped like a cross, enclosing a first chamber and a second chamber in a vertical direction and having a passageway in a horizontal direction. The control element is glidingly movable in the vertical direction in the first chamber. The tube is placed in said second chamber. The spring is inserted between the control element and the tube and pushes the control element to perform a vertical movement. The connecting pipe is connected with the first tube, transmitting water pressure from a supply pipe to the first tube. The piston block is pushed inward by the water pressure, narrowing the passageway, while being pressed outward by the elastic force, so that controlled water flow and pressure in the supply pipe are achieved.

Abstract: A rupture disk assembly comprising two rupture disks which form a chamber. The chamber is connected by a first line to the interior of a vessel on which said rupture disk assembly is mounted and a valve in the line reduces the pressure in the chamber to less than 90% of the pressure of said vessel. A second line connects the vessel and a pilot valve, and a third line connects the chamber to the pilot valve and has a pressure reduction valve in the line to prevent flow from the pilot valve to the chamber. The pressure in the chamber is static and said pilot valve is closed while the pressure in the vessel is at or below the set pressure of the pilot valve and a flow is established through said chamber when the pressure in the vessel exceeds the set pressure of the pilot valve.

Abstract: An improved adjustable fluid flow regulator having a regulator chamber, a moveable diaphragm within the regulator chamber, a spring that acts upon the diaphragm to regulate the flow of fluid, and a first adjustment member and second adjustment member for adjustably biasing the spring against the diaphragm. The improvement includes a tamper resistant feature for restricting adjustment above a predetermined limit. The first adjustment member is fully adjusted to a limit. The second adjustment member is adjusted to bias the spring to a predetermined maximum setting, and restricted from further adjustment. The first adjustment member would subsequently be adjustable to any setting up to the predetermined limit.

Abstract: A pressure control valve automatically controllable of a set value of a pressure circuit by pilot operation without using an electrical signal, is provided. A pressure control valve include a valve body (30) opposing to a seat surface of a relief port (A) connected to a pressure circuit (46) and a spring (32) biasing the valve body (30) onto the seat surface, for flowing out a part of the fluid within the pressure circuit (46) to hold the fluid pressure in the pressure circuit (46) at a predetermined set pressure when the fluid pressure in the pressure circuit (46) is higher than or equal to the set pressure. A pilot piston (40) is arranged movably in expansion and contraction direction of the spring (32) at an end portion of the spring (32) remote from the valve body (30), the pilot piston (40) moves in a direction for compressing the spring (32) when a predetermined pressure of a pilot fluid is input.

Abstract: A wellhead safety valve control system for opening and closing subsurface and surface safety valves in a predetermined sequence and certain components used with such control system. Dump valves in both latching and non-latching configurations are utilized within the control system. Embodiments of the dump valve may incorporate a time delay feature to ensure the subsurface safety valve is closed after a desired time period following the closure of the surface safety valve in the event of flowline anomalies. Provision is made for independent closure of the surface safety valve without closure of the subsurface safety valve.

Abstract: A system for transferring a hazardous fluid product from a transport tank (10) of a roadway vehicle (12) to a fixed storage tank (14). A flexible transfer hose assembly (30) has end couplings (34, 36) which are detachably connected between the transport tank (10) and storage tank (14). A gas operated product supply valve (44) is opened by pressurized gas to permit flow of the hazardous product, such as propane, from tank (10). A gas control valve (46) controls the flow of pressurized gas to gas operated product supply valve (44). Upon a separation or rupture of flexible hose (31) or couplings (34, 36), the fluid pressure of the hazardous product in hose (31) is sensed at fluid sensing chamber (94) in gas control valve (46). A reduction in sensed fluid pressure to a predetermined maximum pressure results in movement of piston (82) to the position shown in FIG.

Abstract: A pressure relief valve system is provided with particular application for use in conjunction with a pressurized system containing an incompressible fluid. The system includes a main pressure relief valve in communication with the pressurized system and a pilot valve in communication with said main pressure relief valve. The pilot valve includes a pilot valve body; a pressure chamber that is always in communication with the system pressure; and a sense piston reciprocal in the pilot valve body and which is exposed to the pressure in the pressure chamber. Damping means are provided on the sense piston to improve control of the opening and closing of the valve system. Preferred damping means include at least one labyrinth damping ring that extends downward from the sense piston and is adapted to engage with an upwardly extended damping ring on a hydraulic damping plate.

Abstract: A subsurface well safety valve having a flow tube telescopically movable in a housing for controlling the movement of a valve closure member. A piston and cylinder assembly actuates the flow tube and is in communication with hydraulic control fluid from the well surface on one side and a gas biasing chamber on the second side and includes a spring acting on the flow tube to close the valve. An equalizing system equalizes fluid pressure on opposite sides of the piston and cylinder assembly in the event of a failure in the seal between the piston and cylinder thereby allowing the spring to close the valve. The equalizing system uses fewer components than previous designs and utilizes a new reference chamber design that allows the reference chamber and the piston to be positioned within the same axial length reducing the overall length of the safety valve over previous designs.

Abstract: A pressure relief system includes a relief valve for selectively discharging process media from a pressure vessel, a pilot valve for controlling the relief valve, and an isolation system for isolating the pilot valve from the process media. The pilot valve has an inlet port, a control port in communication with a dome chamber of the relief valve, and a discharge port. The isolation system includes an accumulator such as a piston-type or bladder-type accumulator, a source of pressurized control fluid, a pressure regulator, and a check valve. The accumulator has an interior chamber with an inlet in communication with an inlet of the relief valve and an outlet in communication with the inlet port of the pilot valve. An isolator such as a piston or bladder divides the interior chamber into a first portion and a second portion and prevents flow therebetween to isolate process media (located in the first portion) from control fluid (located in the second portion).

Abstract: In a vacuum pressure control system constituted of a vacuum vessel, a vacuum pump sucking gas in the vacuum vessel, a vacuum proportional opening and closing valve disposed on a pipe connecting the vacuum vessel and the vacuum pump, the vacuum proportional opening and closing valve changing its opening to change the vacuum pressure in the vacuum vessel, a pressure sensor to measure the vacuum pressure in the vacuum vessel and a vacuum pressure control device to control the opening of the vacuum proportional opening and closing valve based on the output of the pressure sensor, the vacuum proportional opening and closing valve is provided with a valve seat, a valve member with a tapered surface in its outer periphery and a pilot valve, the valve member being movable along a center line of the valve seat to change a clearance area between the valve seat and the tapered surface, and the vacuum pressure control device controls a servo valve to change the pressure of air to be supplied to the pilot valve based on t

Abstract: An intelligent pressure regulator for maintaining a fluid in a process at a predetermined pressure includes an electronic controller which enhances regulator performance and provides self-diagnostics and communications capabilities. The electronic controller includes a pressure sensor which provides a signal indicating the pressure of the fluid being controlled, an adjusting pressure for adjusting the position of a throttling element; and a PID controller which receives the signal indicating the pressure of the fluid being controlled and applies the adjusting pressure to the actuator in response to the signal.