Abstract: In a method for determining the closure time for a valve, operated by a piezoelectric actuator, in order to record the closing time, the voltage at the piezoelectric actuator is recorded and the time is recorded at which the voltage has a maximum difference value from a comparison curve. The difference curve is generated between a start and an end point for a measured curve, having the voltage values applied to the piezoelectric actuator. A precise determination of the closing time can thus be carried out.

Abstract: Disclosed is an infinitely variable directional valve comprising a seat slide on which a valve cone is formed which is prestressed counter to a valve seat in the initial position of the directional valve. The directional valve is configured with a pilot control device wherefore a pilot control valve seat which interacts with a pilot control valve cone is provided inside the closing cone.

Abstract: The disclosure relates to a control device for a pneumatically operated actuator in the field of process automation, in particular for continuous control of material flows in the industrial environment. The control device has a communications interface for receiving an electrical setpoint value, and an output for the output of a pneumatic fluid, whose pressure is varied as a function of a control deviation. The received electrical setpoint value is suitable as a process parameter. The control device is connected via a communications channel to an actual-value encoder, which is designed to output an electrical signal corresponding to the actual value of the same process parameter.

Abstract: An apparatus for controlling water flow is provided. The apparatus is a novel electronic water controller capable of operation using a battery-type power source, and providing for achievement of long battery life. The apparatus generally comprises an electronic control module, a vacuum pressure sensor, a trigger switch, a vacuum switching module and a means to electrically connect the electronic control module to a power source.

Abstract: The solenoid valve device (1) comprises a duct (3, 10, 10?, 4) with an inlet (3) and an outlet (4) and in which are formed first and second valve seats (5, 6) in series with one another, each between a respective inlet chamber (8, 12) and an associated outlet duct (9, 13), and a first and second interception solenoid valve device (16, 17) associated with the first and second valve seat (5, 6) respectively, and each comprising a respective movable shutter (18; 28) cooperating with one of the seats (5; 6) in the associated inlet chamber (8; 12). Each interception solenoid valve device (16, 17) comprises an electromagnetic control portion (35, 50; 36, 50) which includes a movable core (35, 36) the position of which is controlled by a control winding (50; 50).

Abstract: An improved pilot-operated, “instant-on”, solenoid isolation valve discloses a new fluid passage route to save cost of drilling a longitudinal hole within the primary piston. Also, a new feature of primary piston assembly with a movable seal piston having a specific circumferential surface matching to valve body chamber to restrict fluid from front side into back side of the primary piston to produce pressure difference to induce instant valve open when solenoid is energized initially. It also introduces a channel hole in the flange of the sleeve assembly as a communication channel of supply of gas into the chambers of the back side of primary piston assembly. The diameter of the channel hole is not critical to determine in this new invent. As long as the size of the hole is smaller than that of the bleed hole, it can maintain pressure difference between the front side and back side of primary piston during valve opening operation.

Abstract: A fast-acting, pneumatic diaphragm valve includes a diaphragm valve closure member, a pneumatic piston that provides a closure force on the closure member, and a solenoid pilot valve that controls pressurized air to the piston to cause the piston to move in a reciprocal manner so that the closure member opens and closes the valve. The valve seat seal can be elastomer for enhancing speed, and the solenoid pilot valve can be positioned and configured with air flow longitudinally through or past the solenoid armature to enhance speed.

Abstract: A pressure loaded pilot valve system and method for a regulator valve is provided. The system includes a regulator valve connecting an inlet line to an outlet line, a servo control valve assembly, and a pilot valve assembly. A supply line is connected to the servo control valve, and a pilot loading pressure line connects the servo control valve to the pilot valve assembly An exhaust line connects the servo control valve to the outlet line, thereby avoiding waste, pollution, etc. associated with bleeding excess pilot pressure to the atmosphere.

Abstract: Systems and methods for using a dual-path fluid routing system that uses a flow restriction device to enhance temperature and pressure control of fluid are provided. Systems and methods for using a setpoint pressure control system to accurately control the setpoint pressure of a regulator are also provided.

Abstract: A valve has a valve body including a main chamber having a first port and a second port, and a main poppet disposed within the main chamber. The main poppet includes a first surface forming a control chamber within the main chamber. The valve has a first passage communicating the control chamber with the first port, and a second passage communicating the control chamber with the second port. The valve also includes a pilot valve having a pilot poppet for controlling fluid flow from the control chamber to the first port through a third passage, and to the second port through a fourth passage, respectively. The valve may further have a feedback spring coupled between the main poppet and the pilot poppet to provide a force relative to a distance between the main poppet and the pilot poppet.

Abstract: The invention relates to a running tool for subsea junction plate assembly installation. The invention further relates to a method for installing a junction plate assembly using the running tool of the present invention.

Abstract: A metering valve for a work machine hydraulic system is disclosed. The metering valve has a valve body with an inlet and an outlet. The metering valve also has a main poppet disposed within the valve body between the inlet and the outlet. The main poppet has a nose end and a chamber end, and is movable between a flow-passing position at which fluid flows from the inlet to the outlet, and a flow-blocking position at which fluid flow between the inlet and outlet is blocked. The metering valve also has a pilot element movable to selectively communicate the chamber end of the main poppet with a drain, thereby affecting movement of the main poppet between the flow-passing and flow-blocking positions. The metering valve further has a solenoid mechanism operable to move the pilot element. The position of the pilot element is affected by a fluid pressure at the inlet.

Abstract: An electro-pneumatic air pressure regulator includes a primary pressure introduction port, a secondary pressure output port, a pilot pressure chamber, a main valve for opening and closing a communicating conduit, a floating piston which actuates the main valve, a nozzle conduit via which the pilot pressure chamber is communicatively connected to the atmosphere, a flapper which includes a leaf spring facing an open end of the nozzle conduit, and an electromagnetic drive system which deforms the leaf spring to vary a position of the flapper relative to the open end of the nozzle conduit in accordance with the magnitude of an analogue input signal. The flapper includes a conical projection which projects toward the open end of the nozzle conduit. A conical recess corresponding to the conical projection is formed on an end face of the nozzle conduit around the open end thereof.

Abstract: A gas valve body with a first flow chamber and, a second flow chamber including and a main valve positioned in line and between the first flow chamber and the second flow chamber. The main valve can be opened by creating a pressure differential across the main valve. An electrostatically controlled pilot valve is provided for controlling the pressure differential across the main valve for “on-ff” operation. The electrostatically controlled pilot valve may also be operated to “modulate” the pressure differential across the main valve along a range of pressure differential values.

Abstract: A device is disclosed for controlling a variable displacement compressor. The device comprises a microvalve operated control valve. A microvalve device for controlling fluid flow and a micro spool valve for use as a microvalve are also disclosed.

Abstract: In a switching valve containing a valve member for opening and closing a valve seat and a piston for driving the valve member by the action of a pilot fluid pressure inside a valve housing, a magnet for positional detection is attached to the piston, two sensor attachment grooves extending in the direction of the axial line L of the switching valve and having different groove lengths in accordance with the operational position are formed in parallel on the side face of the valve housing, and magnetic sensors are attached at locations on the side of the innermost end wall in the attachment grooves.

Abstract: A water supply system comprising a supply line and a network of consumers, one of which being a monitored consumer who receives the least amount of pressure, a pressure regulation system comprising a pressure reducing valve (PRV) associated with a pilot valve preset to a nominal output pressure and a pressure control system comprising a differential control valve (DCV). A pickup unit is provided for measuring a flow parameter indicative of the pressure at the monitored consumer and emitting a pressure signal to a controller generating in turn a control signal responsive to the pressure signal to activate an actuator of the DCV thereby governing the flow rate through the DCV, so as to obtain desired pressure at the monitored consumer, regardless of altering flow rate through the PRV.

Abstract: Hydraulic actuator as an element of a system for controlling an engine valve is presented. The actuator includes a fluidic actuation chamber, defined by an actuation piston that increases chamber volume as the actuation piston is urged away from a neutral. Chamber includes a high pressure fluid inlet and a fluid outlet. A fluidic actuator control chamber, defined by a control piston connected to the actuation piston that increases chamber volume as the actuation piston is urged away from neutral. A control fluid outlet is connected to a fluid control spool valve. The fluid outlet of the actuation chamber is fluidly connected to an inlet of the control valve. There is a valve actuation plunger operably connected to the actuation piston, and a drain outlet to maintain a fluidic backpressure to the actuator control chamber.

Abstract: A bathroom flusher includes a flusher body, a valve assembly, an electronic control system, and a flusher cover. The flusher body includes an inlet and an outlet, and is designed to accommodate the valve assembly that controls water flow between the inlet and the outlet. The valve assembly includes a valve member movable with respect to a valve seat providing a sealing action based on applied pressure on the valve assembly. The bathroom flusher also includes an external cover designed for enclosing an electronic control module comprising a battery, a sensor, and an actuator for controlling operation of the flush valve, wherein the external cover includes at least two cover parts separately removable, and wherein the external cover is attachable with respect to the valve body in a manner also allowing removable attachment of the control module.

Abstract: A self-cleaning filter for use in a valve is disclosed. The valve can include a bore, an orifice disposed in the bore for accommodating a fluid flow therethrough, and a filter disposed in the bore between the input port of the fluid flow being filtered and the orifice being protected. The filter can include an entrance head in predetermined spaced relationship with the bore of the valve to define a filter entrance and a body portion. The entrance head can be configured to prevent particles of a predetermined size from entering the filter entrance. The body portion can include at least a portion that has a different shape than the entrance head which cooperates with the bore to define a fluid passage. The fluid passage can have an exit port which is communicable with the orifice to send filtered fluid to the orifice. The filter can include an offset portion which extends beyond an end face of the bore which is useful to develop pressure gradients which provide for a self-cleaning function.

Abstract: A pinch valve includes a body with a passageway extending therethrough, a flexible sleeve mounted within the body and surrounding the passageway, and a cavity between the sleeve and the body. An inlet opening provides control fluid flow into the cavity, while an outlet opening allows for fluid exhaust from the cavity. The diameters of the inlet and outlet openings are fixed, with the inlet diameter being smaller than the outlet diameter. A two-way control valve opens and closes the outlet opening, and thereby controls opening and closing of the pinch valve.

Abstract: An actuating device for hydraulically securing a camshaft of an engine of a motor vehicle in a start position has a solenoid valve controlling the flow of a pressure medium to a camshaft adjuster with a rotary slide valve that is fixedly connected to the camshaft and moves the camshaft into the required start position according to the pressure medium supplied to it by the solenoid valve.

Abstract: A two stage solenoid control valve is described. The control valve opens and closes using a single source of pressurized fluid. This source of pressurized fluid may be transmitted through the solenoid control valve and on to a downstream valve such as a bleed valve in a gas turbine engine.

Abstract: A method of controlling the speed of the valves in an electro-hydraulic actuation unit for the valves of an internal combustion engine in which the pressure of the fluid in the hydraulic actuator of the valve is controlled during the final phase of closure of a valve.

Abstract: The object of the present invention is to provide a camless valve driving device, without having a cam mechanism, which can reduce the valve driving energy and enhances fuel efficiency. According to the one preferred aspect of the present invention, the valve driving device of an internal combustion engine includes a pressure chamber, to which actuating fluid, to drive opening and closing of a main valve serving as an intake valve or as an exhaust valve of the internal combustion engine, is supplied; a first actuating valve for supplying high-pressure (Pc) actuating fluid to the pressure chamber during a prescribed period (tCP1) of the initial valve opening period of the main valve; a second actuating valve for introducing low-pressure (Pf) actuating fluid to the pressure chamber after the prescribed period (tCP1) has elapsed; a third actuating valve for discharging actuating fluid from the pressure chamber when the main valve is closed.

Abstract: The invention relates to a valve system comprising a housing, an actuator, a main valve disposed between an inlet chamber and an outlet chamber, and a pilot chamber. Said pilot chamber is linked with the outlet chamber via a main valve, comprising at least one pilot valve member and one valve body linked with the electromagnetic actuator, and with the inlet chamber via at least one connecting channel. The invention is characterized in that the stationary seat of the main valve is formed by an insert that is mounted in the; housing of the valve system. The main valve member is impinged upon on its diametrically opposed surfaces by the pressure present in the inlet chamber and the pressure present in the pilot chamber. The pilot chamber is linked with the inlet chamber via a connecting channel that extends through the main valve member. The pilot valve member is formed by the insert mounted in the housing of the valve system or by the housing.

Abstract: A pilot-controlled electromagnetic valve is capable of preventing tilting of a piston and of shortening the piston with a simplified arrangement and allows a main valve element to be moved by actuation of a manual controller by transmitting the motion of the manual controller to both the piston and the main valve element. A partition is formed between a piston chamber and a manual controller chamber. A guide hole is formed in the partition. A guide projection is formed on the left side of the piston. The guide projection is inserted through the guide hole to project into the manual controller chamber. The manual controller having a sloped surface is reciprocatably provided in the manual controller chamber. Actuation of the manual controller causes the sloped surface to contact the sloped portion of the guide projection, thereby enabling both the piston and the main valve element to be moved.

Abstract: A sliding spool valve (1) is provided for controlling flow of fluid especially between an inlet (2) at a relatively high pressure and an outlet (6) at a relatively low pressure. Wherein the spool valve is reciprocally displaced between open and closed positions by hydraulic action of the transmitted fluid.

Abstract: A pilot valve has: an input passageway, an output passageway, a rotatable shaft disposed between them, a permanent magnet affixed to the rotatable shaft, an electromagnet, a control element, and a failsafe magnet. The rotatable shaft has a slot that gives the rotatable shaft a varied cross-section as a function of its position. The slot is disposed to permit fluid to flow between the input passageway and the output passageway except when the rotatable shaft is in a closed position. The electromagnet is disposed to generate first magnetic field that, via the permanent magnet, drives the rotatable shaft away from the closed position. The control element places a PWM current on the electromagnet, such that the length of the duty cycle controls the strength of the first magnetic field. The failsafe magnet is disposed to generate a second magnetic field that drives the rotatable shaft away from the closed position.

Abstract: A diaphragm operated valve having the diaphragm attached at its lower end to a valve closure plug, and movable therewith, and attached at its upper end to a portion of valve body that forms the pressure cavity. The diaphragm has a stepped portion between its upper and lower ends which folds back on itself when the valve opens. The valve body has shoulder portions that support the diaphragm when the valve is closed to avoid stressing the diaphragm material due to pressure in the pressure chamber. This allows the outside diameter of the diaphragm to be minimized, and eliminates the need for fabric reinforcement. A filter screen is positioned flush with the surface of the valve plug so that high velocity flow across the screen while the valve is opening and closing removes accumulated dirt thereby making the screen self cleaning.

Abstract: An electrically powered rotary solenoid drives a hydraulic pilot valve to actuate a hydraulic main valve. The pilot valve includes a seal carrier rotatable with respect to a seal plate. A carrier supply port and a plate supply port are centered about an axis of rotation to remain in fluid communication during rotation. A carrier function port and plate function port are spaced from the axis of rotation, such that they may be selectively placed in fluid communication to pass fluid to actuate the main valve. When actuated, the main valve passes fluid pressure to one or more hydraulically actuated components.

Abstract: An electro-hydrostatic actuator having a sealed housing filled with a dielectric fluid. A motor driven pump and electronics for controlling the pump are all immersed in the fluid. The pump is arranged to deliver fluid from the housing to a hydraulic cylinder to control the positioning of the piston rod. A solenoid operated valve is integrated as a bypass or tip valve for quick fail safe position. The actuator is ideally suited to control various types of plunger valves. In one embodiment of the invention, the hydraulic cylinder is located outside of the housing and in another embodiment the cylinder is located inside of the housing.

Abstract: A double valve flusher includes a body, a separating plate, an upper and a lower valve base, a movable valve, a film valve, a fixing member, and an electromagnet. An upper leak room is formed between the film valve and the upper valve base. A leak room is formed between the separating plate, the lower valve base and the movable valve contained in a chamber in the body. The upper leak passageway in the upper leak room and the upper valve base is blocked or opened by the core of the electromagnet, thus controlling the film valve in disfiguring to block or open the leak passageway of the leak room and the lower valve base. Then the movable valve is controlled to move up and down to flush or stop flushing water into a urinal where this flusher is positioned.

Abstract: A valve actuator control monitors engine valve trajectory, lift and seating velocity and varies the timing of internal feedback control channels to correct for engine valve positioning errors to achieve precise engine valve lift, closing timing and desired seating velocity.

Abstract: The object of the present invention is to provide a solenoid control valve simple in construction and low in cost, realized by reducing the number of component parts, eliminating screw-joined portions, and minimizing the use of rubber O rings. A valve hole of a pilot valve, a hole of a bearing for supporting one end of a shaft of a solenoid, and a fitting hole in which is fitted one end of a sleeve, are formed along the same axis in a body. This makes it possible to accurately establish the concentricity of movable components of the solenoid when the sleeve is fitted in the fitting hole, and hence, a pilot valve element can be integrally formed with the shaft. Set values for a main valve and the pilot valve are adjusted by adjusting the amounts of insertions of a press-fit member and a bearing by press-fitting.

Abstract: An axial valve has a housing, an inlet, an outlet, a valve seat between the inlet and the outlet, and a valve element cooperating with the valve seat, and is controlled by a pilot valve arranged between the inlet and the outlet, with the valve element being moveable parallel to a flow path from the inlet to the outlet and surrounding an interior space. Without changing the external measurements of the valve an increased through flow is achieved in that a first section of the flow path leads through the interior space and a pressure space is arranged between the housing and the valve element, in which pressure space in the closed condition of the pilot valve a closing pressure is formed and applied to the valve element.

Abstract: A cylinder head for a combustion cylinder of an internal combustion engine is provided, which has at least one inlet opening and at least one outlet opening, as well as gas exchange valves which are operable by electrohydraulic valve actuators, some of which gas exchange valves function as inlet valves to control the at least one inlet opening, and some of which gas exchange valves function as outlet valves to control the at least one outlet opening. For the purpose of producing a compact, complete module which, as a separate component, may be tested for reliability and may be installed into the engine block of the internal combustion engine without additional preassembly effort, the cylinder head is provided with at least one high pressure line for supplying fluid under high pressure and at least one recycling line for recycling fluid, which have coupling openings for the hydraulic coupling of the valve actuators, and also means for fastening the valve actuators are provided.

Abstract: A compound valve assembly for controlling oil flow includes a first and a second valve. The first valve is a pressure relief valve including a spring-biased plunger in a side gallery opening off a primary oil supply gallery leading to a pressure-actuated device. The relief spring allows oil above a predetermined pressure to displace the plunger and to be returned to an oil sump. The side gallery is closable by a secondary valve seat and a solenoid-actuated valve head. A passage through the plunger leads to the second valve seat. When the solenoid is deactivated, oil flows through the passage, through the second valve, and is returned to the sump. When high pressure is desired at the device, the solenoid closes the second valve. Captive oil assumes the same pressure as the supply pressure, and the relief valve function is disabled, causing high pressure oil to flow to the device.

Abstract: An engine valve actuation system is provided that includes an engine valve that is movable between a first position where the engine valve prevents a flow of fluid and a second position where the engine valve allows a flow of fluid. A cam assembly is operatively connected to the engine valve to move the engine valve between the first position and the second position in a predetermined actuation pattern. A valve actuator having a piezo electric device is operable to change the movement of the engine valve from the predetermined actuation pattern. A controller is adapted to control the piezo electric device to achieve a desired valve actuation pattern.

Abstract: A fuel injector for the direct injection of fuel into the combustion chamber of a mixture-compressing internal combustion engine having external ignition includes a piezoelectric or magnetostrictive actuator and a valve needle, which, via a compensation element, is in operative connection to the actuator, a valve-closure member being formed on the valve needle, which cooperates with a valve-seat surface to form a sealing seat. The compensation element is filled with a rheological liquid.

Abstract: A valve actuator assembly for an engine includes a movable engine valve, a movable spool valve and four on/off valves. An intermediate channel interconnects the spool valve and first and second on/off valves. A driving channel connects the spool valve and a first fluid chamber for driving the engine valve. First and second feedback channels communicate between the second and third fluid chambers and fourth and fifth fluid chambers of the spool valve. Third and fourth on/off valves enable and disable the feedback channels to improve valve controllability.

Abstract: A flush valve includes a body having an inlet and an outlet. There is a main seat assembly at the outlet. An outer cover is attached to the body and an inner cover is attached to the body within the outer cover. A piston is movable within the body and inner cover and, with the inner cover, defines a pressure chamber. The piston carries an exterior seal which bears against an inside wall of the inner cover during movement of the piston. A refill orifice in the piston connects the chamber with the body inlet. Pressure in the chamber maintains the piston closed upon the main seat assembly. A relief valve is positioned in the piston for venting the chamber to the outlet. When the relief valve is opened and the chamber is vented, the piston moves away from the main seat assembly connecting the inlet with the outlet.

Abstract: An automatic flush actuation apparatus, which is incorporated with a flushing system having a water inlet, a water outlet, and a water chamber communicating therebetween, that includes a valve member being moved by a flush lever for releasing the water pressure within the water chamber to allow the water passing from the water inlet to the water outlet, and a sensor-operated powering assembly including a relief valve, which includes a resilient element for retaining a valve stopper to normally close the water passage, provided at the valve member for controlling the water flowing to the water outlet and an actuator arranged in such a manner that while sensing a presence of a user of the flushing system, the actuator is driven to move the relief valve to an opened position for releasing the water pressure within the water chamber to allow the water passing to said water outlet.

Abstract: A flush valve includes a body having an inlet, an outlet and a main seat assembly between the inlet and outlet. A piston moves within the body and with the body defines a pressure chamber which is used to normally maintain the piston closed upon the main seat assembly. There is a refill orifice in the piston connecting the pressure chamber with the inlet. A relief valve is carried by the piston for venting the pressure chamber and there is a fluid driven apparatus for opening the relief valve, which apparatus is attached to the body. A hydraulic bypass in the body is connected to the fluid driven apparatus. The main seat assembly has a plurality of peripherally disposed fluid passages connecting the hydraulic bypass and the inlet to provide filtered fluid to the fluid driven apparatus. A first seal on the main seat assembly has a flat portion and an arcuate portion constrained within a channel. Lockout lugs formed in the seal prevent installation of an incorrectly sized piston.

Abstract: A hydraulic damper cylinder 270 is provided for an electromagnetic actuated internal combustion engine cylinder valve 20. The damper includes a piston 68 slidably mounted within the damper cylinder 270. The piston 68 bifurcates the cylinder 270 into a first control volume 74 and a second control volume 76. The first and second control volumes are fluidly connected by an inboard flow path 372. Along the extreme ends of travel, the flow path 372 is blocked by the piston 68 and damping occurs through fluid transfer through an outboard flow path 374.

Abstract: A lost motion assembly for a valve of an internal combustion engine includes a cam, a cam piston which is spring biased to follow motion of the cam, a valve piston operatively engaged with a poppet valve, and an auxiliary piston. The cam piston, valve piston and auxiliary piston are in continuous contact with a fluid in an enclosed control chamber having a fixed volume, such that rotation of the cam causes displacement of the cam piston into the control chamber, which causes a corresponding displacement of at least one of the valve piston and auxiliary piston while the volume of fluid in the control chamber remains substantially constant.

Abstract: A servomechanism for a valve controlling engine intake flow via a cooler and a bypass uses a proportional solenoid operating a hydraulic valve to power a hydraulic actuator setting the position of the control valve. An engine sensor and electric controller provide input to the proportional solenoid, and feedback from the position of the control valve is applied to the hydraulic valve by a cam and spring applying a force in opposition to the proportional solenoid.

Abstract: An apparatus for controlling gas exchange valves includes at least one valve positioner, associated with a gas exchange valve, and a pressure supply device which supplies the valve positioner with a fluid under high pressure. The valve positioner encompasses a working cylinder having a positioning piston, coupled to the gas exchange valve, which delimits an upper pressure space for opening the valve and a lower pressure space for closing the valve, and encompasses a control valve controlling the hydraulic pressure in the pressure spaces. In order to reduce the manufacturing costs and electrical energy demand of the apparatus, the upper pressure space is connected directly, and the lower pressure space via a restrictor throttle, to the pressure supply device; and the control valve is connected to the lower pressure space and to a relief line. Depending on the switch position, the control valve additionally connects the lower pressure space to the relief line or blocks it off from the relief line.

Abstract: There is provided an electromagnetic actuator which includes a coil disposed about a tube bearing a movable armature, the coil being electrically connectable to a circuit configured to provide a current to the coil to generate a magnetic field and magnetic flux in at least one direction. The movable armature is magnetically coupleable with the coil. A flux adjustment element is also provide and is configured for movement within a magnetic flux output by the coil so as to increase a magnetic flux input to the armature upon movement of the flux adjustment element in a first direction and to decrease a magnetic flux input to the armature upon movement of the flux adjustment element in a second direction, wherein the flux adjustment element is externally disposed about a distal end of the tube.

Abstract: A fluid control valve for a pipeline pig includes a main valve and a mechanism for operating the main valve. The main valve comprises a valve body communicated to a fluid pipe, a main valve core movably disposed in the inner chamber of the valve body, and a main valve stem connected to the main valve core. The operating mechanism includes a hydrocylinder, which comprises a piston disposed in the cylinder, and a piston rod connected to the piston. The piston rod is transmissibly connected with the main valve stem so as to drive the main valve core by the main valve stem. A valve device includes a pilot valve, positioned in the pipeline which communicates the fluid pipe with the hydrocylinder, and an operator for controlling the actuation of the pilot valve so as to enable the piston to move reciprocally by the pressure of fluid in the fluid pipe.