Abstract: A spool valve includes a sleeve and a spool arranged on an inside of a sleeve to be movable in a longitudinal direction, the sleeve being provided with an inflow port into which fluid is supplied from an external fluid supply hole, and an outflow port through which the fluid is flown to an outside of the sleeve, wherein a supply groove is formed on an outer periphery of the sleeve, and the supply groove includes an inlet space into which the fluid flows from the fluid supply hole and an outlet space formed on a side of the inflow port with respect to the inlet space in an axial direction.

Abstract: An example spool includes a spool body varying in diameter along a length of the spool body, thereby forming a plurality of lands of variable diameters, wherein a land of the plurality of lands is configured to control fluid flow from a workport passage formed in a valve worksection to a return cavity; and a plurality of axial grooves formed in a circular array about a circumference of the land, wherein the plurality of axial grooves comprises a first set of axial grooves and a second set of axial grooves, wherein an axial length of axial grooves of the second set of axial grooves is greater than a respective axial length of axial grooves of the first set of axial grooves, allowing the axial grooves of the second set of axial grooves to engage the return cavity before the axial grooves of the first set of axial grooves.

Abstract: The invention relates to a hydraulic steering unit (1) including a housing (3), a spool, a sleeve (12) arranged between spool and housing (3), and a measuring motor (14) having a number of working chambers (15), wherein a first commutation geometry (18) and a second commutation geometry (19) are arranged between the sleeve (12) and the housing (3), wherein the commutation geometries (18, 19) are connected to the working chambers (15) of the measuring motor (14) and the housing includes a first direction port (4), a second direction port (5), a pressure port (6), and a return port (7). The object is to have a good steering behavior. To this end one of the commutation geometries (18) is directly connected to the first direction port (4).

Abstract: An example valve includes a housing, a sleeve disposed within the housing and having a first end and a second end opposite the first end, and the sleeve includes a plurality of sleeve protrusions at the first end and a plurality of fluid flow channels are formed between adjacent sleeve protrusions, a seal carrier disposed within the sleeve and having a carrier protrusion that extends from the second end of the sleeve and abuts against an interior surface of the housing, and an end cap mounted to the housing such that the plurality of sleeve protrusions abut against the end cap.

Abstract: A valved manifold module is disclosed, constructed and arranged to be readily connected in a chain with similar modules to form a manifold assembly. The modular manifolds allows for expansion or modification of the manifold assembly to control a group of pneumatically or hydraulically driven pumps, valves or combinations thereof in a liquid flow control apparatus. The valved manifold module can be configured to accept a group of four substantially identical valve assemblies, and can be controlled by a local controller mounted to the manifold module, thus forming an independently programmable valved manifold module. The resulting modular system is expandable to allow for coordinated operations of a liquid flow control system, using substantially independent controller functions originating at the manifold assembly level.

Abstract: A hydraulic arrangement for a vehicle transmission includes a hydraulic pump for providing a system pressure for a first hydraulic system circuit and a lubrication pressure for a second hydraulic lubrication circuit. The arrangement also includes a control valve connected between a pump outlet of the pump and the two hydraulic circuits and has two different switching positions. The control valve, depending on its switching position, acts as a hydraulic connection between the pump and the system circuit or between the pump and the lubrication circuit.

Abstract: A control valve has a housing, which has a first bore in which a control spool is accommodated in such a way as to be movable along a longitudinal axis. The control spool defines first and second orifices which are adjustable. First and second reference planes are each oriented perpendicularly to the longitudinal axis, wherein the first reference plane is defined by a first control edge, more specifically in the position of the control spool in which the first orifice is just closed, wherein the second reference plane is defined by a second control edge, more specifically in the position of the control spool in which the second orifice is just closed. At least one radial recess different from the second bore is provided in the first bore between the first and the second reference plane in the direction of the longitudinal axis.

Abstract: The present invention solves bore wear due to inefficient design of OEM pressure regulator valve through an improved pressure regulator valve with lands having narrower diameters and longer lengths, the lands additionally having a grooved design, and a second land having a beveled edge to stabilize fluid regulation. Narrower lands allow for better ATF lubrication in a bore. Longer lands allow for the valve to be dropped into a bore to interact with non-damaged lengths of the bore without further machining. The beveled edge regulates pressure, further reducing bore wear.

Abstract: A first flow path area at a position where one of multiple openings of a sleeve and one of multiple grooves of a spool overlap with each other is different in size from a second flow path area at a position where another one of the openings of the sleeve and another one of the grooves of the spool overlap with each other. The one opening and the one groove form a flow path for connecting one of one pressure chamber and the other pressure chamber to a fluid supply source, due to displacement of the spool. The other opening and the other groove form a flow path for connecting another one of the other pressure chamber and the one pressure chamber to a fluid discharge port, due to the displacement of the spool.

Abstract: An emergency shut-off device shuts off supply of control oil to a trip-and-throttle valve of a steam turbine and closes the trip-and-throttle valve in an emergency. The emergency shut-off device includes: a cylinder; a piston that slides into the cylinder; a spring that applies a biasing force to the piston; a plurality of piston valves disposed on the piston; and a plurality of chambers that are formed by the piston valves. The control oil is supplied to and drained from the plurality of chambers, and a sliding surface of each of the piston valves has a groove to leak the control oil in a corresponding one of the chambers to another one of the chambers that is adjacent to the corresponding chamber in an axis direction.

Abstract: A pumping system that includes a reciprocating isobaric pressure exchanger (reciprocating IPX) designed to exchange pressures between a first fluid and a second fluid. The first fluid includes a substantially particulate free fluid and the second fluid includes a particulate laden fluid. The reciprocating IPX includes a valve having a first and second piston. The value further includes a shaft coupling the first piston to the second piston and a drive coupled to the shaft.

Abstract: Provided are: a displacement expanding apparatus, which uses environmentally friendly electrical energy to generate rotational power; and an engine including the displacement expanding apparatus, the novel engine having improved performance and a long lifespan. Also, to realize a novel engine, provided is a novel engine which is environmentally friendly and has a long lifespan.

Abstract: A servo valve for an actuator is described. The servo valve comprises a housing having a plurality of ports, a sleeve disposed within the housing, the sleeve comprising an axis (A), an inner surface defining a cavity for the servo valve and a plurality of metering holes, each in communication with one of the ports, and a metering rod extending axially in the cavity for reciprocation along the axis to meter flow through the metering holes. The servo valve additionally comprises a first spring seal extending between the metering rod and the sleeve to close off a first end of the cavity and a second spring seal extending between the metering rod and the sleeve to close off a second, opposite end of the cavity.

Abstract: A control device, for a hydraulic consumer (22) and susceptible to vibrations, includes a valve (24) having a control spool (40) controllable by an actuating device (46). The valve (24) has a pressure supply port (P), to which a pressure compensator valve can be connected, which can be supplied with pressure fluid from a pressure supply device. The actuating device (46) has a motor (74). A load-pressure-dependent force on the control spool (40) can be generated by a control device (66). That force at the control spool (40) acts on an electronic motor controller (208) of the DC motor (74), which detects a change of the force and acts as a damping of the vibrations of the consumer (22) against this change of force.

Abstract: A servo valve comprises a valve housing, a cavity formed in the valve housing and defining a longitudinal axis (X), and a member disposed in the cavity and axially-moveable therein, wherein the member comprises a portion with first and second cylindrical sections having a first diameter (R1, R2), a central section located between the first and second cylindrical sections and having a second diameter (R3), and first and second frusto-conical sections connecting the first and second sections to the central section and forming respective first and second frusto-conical surfaces. A plurality of ports, each form a fluid passage through the valve housing and have first and second nozzles with first and second nozzle openings.

Abstract: An example valve includes: a pressure compensation spool configured to be subjected to a first fluid force of fluid received at an inlet port of the valve; a sleeve having a cavity and at least one throttling cross-hole; a throttling spool disposed in the cavity of the sleeve and configured to be axially movable therein, wherein the throttling spool blocks the at least one throttling cross-hole when the valve is unactuated; and a pressure compensation chamber, wherein when the valve is actuated, the throttling spool moves in the proximal direction to form a throttling flow area between a distal end face of the throttling spool and an edge of the at least one throttling cross-hole, allowing fluid flow from the inlet port to the pressure compensation chamber, thereby causing a second fluid force to be applied on the pressure compensation spool, allowing flow to an outlet port of the valve.

Abstract: A servo valve for an actuator is described. The servo valve comprises a housing and a sleeve provided within the housing having a plurality of metering holes for communication with a cavity within. The servo valve further comprising a metering rod provided with metering members on a central rod for metering flow into and out of the cavity through the metering holes. The metering members comprise annular elements which are located axially on the central rod by an interference fit. The position of the metering members can be adjusted through using heat to thermally expand the metering member relative to the central rod to release the hold of the friction fit, allowing the metering member to be repositioned by being slid along the central rod.

Abstract: The present disclosure provides a high flow coefficient spool valve (50) through one or more changes in the flow path from a conventional spool valve. The body (56) of the spool valve includes spherically contoured internal grooves (68). The spool (58), slidably engaged inside the body (56), includes concave surfaces between seals (62) that is complementary to the spherically shaped internal grooves (68) of the body. The spherical shape of the body internal grooves (68) and/or concave shape of the spool allow more volume and more laminar flow therebetween, resulting in an increased flow coefficient and flow capacity. The body also is formed with transverse port windows in the port that contour into a bore of the body adjacent the spool. A choke volume in the flow is strategically designed in a parallel flow location rather than a perpendicular flow location to promote laminar flow and lessen turbulence to also increase the flow coefficient.

Abstract: A slide for a fuel circuit valve of an aircraft engine extending along a longitudinal axis, and comprising a narrowed intermediate portion extending between two cylindrical end portions, a first end portion being separated from the narrowed intermediate portion by a shoulder having a surface arranged overall perpendicular to the longitudinal axis, the narrowed intermediate portion including in turn, as an extension of the shoulder, at least one cylindrical portion, the shoulder comprising at least one groove which extends radially from the cylindrical surface of the first end portion, towards the longitudinal axis, and which forms a fuel recirculation area which provides the generation of a jet of fuel on the cylindrical portion of the narrowed intermediate portion, when fuel flows along the first end portion towards the narrowed intermediate portion and the second end portion.

Abstract: A spool for a fuel circuit valve of an aircraft engine, extending along a longitudinal axis and including a narrowed intermediate section extending between two end cylindrical sections, a first end section being separated from the narrowed intermediate section by a shoulder having a surface arranged overall perpendicular to the longitudinal axis, the narrowed intermediate section also including, extending away from the shoulder, at least one cylindrical portion, and the shoulder is provided with a step extending away from the cylindrical surface of the first end section which, when the fuel flows along the first end section towards the narrowed intermediate section and the second end portion, generates a jet of fuel on the cylindrical portion of the narrowed intermediate section, a recirculation of fuel forming in an area in front of the shoulder.

Abstract: A spool valve includes: a valve body that has a spool hole; and a spool disposed in the spool hole and movable in an axial direction, wherein the spool has a first large-diameter portion, and a small-diameter portion provided on one side in the axial direction of the first large-diameter portion, the first large-diameter portion has a first outer surface slidable with an inner surface of the spool hole, an end surface connected to an end portion at the one side in the axial direction of the first outer surface and to an end portion at the other side in the axial direction of an outer surface of the small-diameter portion, and a cutout portion provided on the end surface, and a bottom surface of the cutout portion is inclined toward the one side in the axial direction to approach a central axis of the spool.

Abstract: The invention relates to a pressure-volume delivery system comprising a piston-cylinder unit with a piston acting on both sides (dual-action reciprocating piston), said piston having at least two different active surfaces in corresponding pressure chambers and the pressure chambers being connected to at least one consumer via hydraulic lines. The delivery system also comprises a drive for the piston-cylinder unit. According to the invention, the pressure chambers and/or hydraulic lines are interconnected by means of at least one or more switching valves connected in parallel and having a large flow cross-section (AV) and via a short hydraulic line or lines with low flow resistance.

Abstract: A waste heat recovery device including: a heater which evaporates an working medium by exchanging heat between supercharging air supplied to an engine and the working medium; a heat exchanger which heats the working medium by exchanging heat between the working medium which has flowed out from the heater and a heating medium; and an expander into which the working medium which has flowed out from the heat exchanger flows; a motive power recovery device; a condenser which condenses the working medium; and a pump which sends the working medium to a heater.

Abstract: An actuation mechanism for a valve comprises a first member having a generally spherical surface on a first side of a bisecting line and a generally ellipsoidal surface on a second side of the bisecting line. The first member is rotatable around a central point of the bisecting line. The valve has a second member with a truncated ellipsoidal surface on both sides of a bisecting line. The second member matingly engages the first member at the first member ellipsoidal surface. The valve also includes a longitudinal member coupled to the second member and a biasing member coupled to the longitudinal member. The first member is rotated around the central point from a first position to a second position to move the second member and the longitudinal member linearly. The biasing member returns the first member and second member to the first position upon release of the first member.

Abstract: A switching valve for an internal combustion engine having an adjustable compression ratio. The switching valve includes a switching element having a groove, and a sleeve-shaped connecting section, which has a first bore, which connects the switching valve with a first hydraulic fluid line, a second bore, which connects the switching valve with a second hydraulic fluid line, and a venting bore, which connects the switching valve to a venting duct. The switching element is guided so as to be movable in the connecting section by forming a gap between the surface of the switching element and a corresponding guide face of the connecting section. In a first switched position of the switching valve, the groove connects the first hydraulic fluid line to a venting duct. In a second switched position, the groove connects the second hydraulic fluid line to the venting duct.

Abstract: A mechanical seal comprising an elastomeric modified O-ring in combination backup rings typically made of a low friction material such as Teflon with matching surfaces to modified O-ring surface to provide low dynamic friction and meantime prevent seal extrusion due to high pressures and temperatures.

Abstract: A solenoid spool valve including a spool valve having a sleeve provided with a supply pressure port, a control pressure port, an exhaust port and a spool supported in the sleeve for axial displacement within the sleeve; and an electromagnetic actuator for providing an axial drive force to the spool in a first axial direction; wherein the spool has a first piston with a first land for opening/closing the supply pressure port and a second piston with a second land for opening/closing the exhaust port, wherein the first piston has a larger piston face surface area in fluid communication with the control pressure port than does the second piston.

Abstract: A valve includes a housing including a plurality of ports including an inlet port in communication with a radiator. The valve includes a cylinder located in the housing that includes a plurality of apertures and a fail safe opening. The cylinder is moveable such that one of the plurality of apertures can be aligned with one of the plurality of ports of the housing to determine a flow of a fluid through the valve. The valve includes a moveable feature moveable with and relative to the cylinder, and the moveable feature covers the fail safe opening of the cylinder when a temperature of the fluid flowing through the valve is below a threshold temperature.

Abstract: Two cylinder devices are respectively connected to two flow path switching devices; first and second position detectors which detect movement and passage of a piston are disposed at one end side of the two cylinder devices; and third and fourth position detectors are disposed at an interval more toward the one end side. The cylinder device in the filling process is set to the pressure feeding process by a flow path switching device in accordance with signals of the first and second position detectors of the cylinder device in the pressure feeding process, and the cylinder device in the pressure feeding process is subsequently set to the filling process by a flow path switching device in accordance with signals of the third and fourth position detectors.

Abstract: Various embodiments of valve assemblies are provided for use in connection with the fluid systems of machines such as engine-powered machines. The valve assemblies may be used for performing fluid refill operations, fluid evacuation operations, fluid purge operations, and other types of fluid operations in connection with machine maintenance.

Abstract: A throttle housing having an inlet end and an outlet end includes a shuttle housing disposed within the throttle housing. The shuttle housing has a first end cap at a first end and an orifice array therethrough. The shuttle housing comprises a shuttle housing therein. The shuttle has an opened position and a closed position relative to the shuttle housing. The shuttle defines a varying control volume between the end cap, the shuttle and the shuttle housing. The control inlet fluidically communicates a control fluid to the control volume to control the position of the shuttle in the shuttle housing.

Abstract: A solenoid valve is provided having a hydraulic body with an undulated expansion artery to prevent an exchange of fluid between an interior of the hydraulic body and the exterior of the solenoid valve.

Abstract: A hydraulic valve arrangement, in particular a control valve arrangement of an axial piston machine, includes at least two valves that have springs supported in each case on a spring seat. The two spring seats are connected to one another with a material-to-material fit in one or more of a non-positive manner and a positively locking manner.

Abstract: A hydraulic spool valve includes a housing, a valve element disposed within the housing, a first piston coupled to the valve element, and a first biasing member. The housing includes a pair of first ports. The valve element is selectively moveable within the housing between a first closed position and a second open position allowing fluid communication between the first ports. Hydraulic pressure against the first piston causes helical translation of the piston in a first direction, and motion of the valve element in a first direction from the first position toward the second position. The first biasing member is configured to bias the first piston and the valve element toward the first position.

Abstract: The invention relates to a central valve for a pivot motor actuator. A housing tube of the central valve includes radial recesses for operating connections. A piston of the central valve has a center position. In the center position both radial recesses are covered by annular bars of the piston towards the tank drain connection by overlaps. Thus, pressure spikes from the operating connections to the check valves are strongly throttled.

Abstract: Provided is a fast switching hydraulic pilot valve with hydraulic feedback for quickly and accurately switching between opened and closed positions of the hydraulic valve. The hydraulic valve includes a valve body, a valve bore defined by the valve body, a plurality of valve ports extending through the valve body and into the valve bore, and an actuator. Actuation of the actuator allows for movement of the spool to a first position within the valve bore, thereby providing for one of opening or closing the hydraulic valve. Exposure of the spool to a pressure at an end of the spool proximate the actuator allows for movement of the spool to a second position within the valve bore, thereby providing for the other of opening or closing the hydraulic valve.

Abstract: An air/water valve assembly for use in an endoscope or other medical equipment is provided. The valve assembly includes a spool and a one-piece sealing member that includes a number of sealing rings. The spool can be injection molded, and the sealing member can be overmolded onto the spool. A spring, retainer, and housing are also included to form the valve assembly. As such, an air/water valve assembly may be made that can be used in a single medical procedure and then discarded in a cost-effective manner. Corresponding methods of manufacturing an air/water valve assembly are also provided.

Abstract: A valve assembly is dimensioned for interconnection between a pressurized gas supply system and a pressurized gas braking system of a rail vehicle. The valve assembly can include a valve housing and a valve body. The valve housing can include a housing wall that at least partially defines a housing chamber and includes a plurality of communication ports in fluid communication with the housing chamber. The valve body is supported within the housing chamber for sliding movement relative to the housing wall. The valve body can be displaced between a plurality of positions in which different ones of the communication ports are in fluid communication with one another. A pressurized gas system and a rail vehicle are also included.

Abstract: A travel control valve includes a valve body and a spool. The valve body includes a first pump port connected on an upstream side from a drive control valve, a first connection port connected on a downstream side from the drive control valve, a second pump port connected to a second pump, and a second connection port connected to a second circuit system. The travel control valve can switch a communication opening between the first pump port and the first connection port to a large opening throttle position in which the communication opening remains smaller than that between the second pump port and the second connection port, and a small opening throttle position in which the communication opening remains smaller than that in the large opening throttle position.

Abstract: A steplessly adjustable hydraulic insert valve has a housing defining a radial direction and an end side in an installation direction. An inflow connector on the end side is connectable to a pressure medium source. First and second working connectors and a return connector are arranged in the radial direction. The return connector is connectable to a pressure medium tank. The housing has an axial bore and an actuator guided movably therein. The actuator can be held in an axial center position by at least one spring and is adjustable steplessly axially out of the center position by controllable actuation. At least one of the working connectors is fluidically connectable to the return connector by axial adjustment of the actuator. The actuator has a radial widened portion with first and second control edges for steplessly opening and/or closing first and second radial openings, respectively, of the return connector.

Abstract: A control valve for an automatic transmission includes a valve body including a chamber and a control pressure port, metering edges formed in the valve body at the control pressure port, a reference surface formed in the valve body, a spool displaceable along the chamber, and a solenoid module including a pin for displacing the spool, and located in the chamber by contact with the reference surface.

Abstract: A valve for dispensing water and air in installations for spraying water under pressure, includes: firstly, a body (2) equipped with two independent circuits (C1, C2), each for circulating a fluid, one air, the other water, each of the circuits including (i) a chamber (5, 15) accommodating a shutter member (6, 16) in the form of a spool, (ii) a duct (7, 17) for admitting the fluid, (iii) a discharge duct (8, 18) for discharging the fluid, and (iv) a drain duct (9, 19) for draining the fluid contained in the discharge duct; and, secondly, control elements for controlling the shutter members so as to make each one move between an open position which allows the fluid to pass and in which the drain duct is shut off, and a closed position in which the fluid is prevented from passing and the drain duct is open.

Abstract: A valve device includes a housing (2) and a valve piston (4) axially displaceable in a piston bore (3) of housing (2). First and second load connections (A, B) can alternately be connected to a pressure connection (P) and to tank connections (T1, T2) by moving the piston from an idle position by first and second solenoids (5, 6). First and second pilot control chambers (7, 9) pressurize first and second piston back sides (8, 10) of the valve piston (4). The pressure in the pilot control chambers (7, 9) is controlled by first and second pilot control pistons (12, 13) movable by the solenoids (5, 7). The pilot control chambers (7, 9) are connected via a connection (11) to the pressure connection (P). The pilot control pistons (12, 13) open or close connections (14) between the pilot control chambers (7, 9) and the tank connections (T1, T2).

Abstract: An oil control valve assembly includes a valve body and a controller coupled to an exterior end of the valve body. The controller includes a solenoid housing attached to the exterior end of the valve body, and defines an interior region. An encapsulated coil assembly is disposed within the interior region of the solenoid housing. A housing seal is disposed within the interior region of the solenoid housing, in sealing engagement with the solenoid housing, the valve body, and the encapsulated coil assembly. The housing seal is operable to seal the interior region of the solenoid housing to prevent fluid communication between the solenoid housing and the valve body. An adapter assembly is coupled to the valve body to reposition a discharge location of a supply port, a control port, and an exhaust port of the valve body along a longitudinal axis of the valve body.

Abstract: Described are water-on-water valves for use in reverse osmosis filtration systems. The water-on-water valves are regulated by the pressure in a product line, which contains fluid from a product line of the filter module and/or the product side of a water-on-water storage tank. Exemplary valves are shuttle valves that are regulated by the pressure downstream of the product side of a reverse osmosis filter module. The valves may comprise a piston within a housing, and an end of the piston may have an enlarged diameter relative to the maximum diameter of the remainder of the piston. The body of the piston may have sections of differing diameters, where the smaller diameter sections form flow channels, or the body may a diameter that is substantially the same along its length in conjunction with gratings and flow channels.

Abstract: An energy-saving valve includes a spool-driving unit which changes the position of a spool to a position at which compressed air is discharged from a first output port without pressure control and includes a pressure control unit which changes the position of the spool to a position at which compressed air is discharged from a second output port in a predetermined pressure level due to pressure control. The pressure control unit includes a pressure control piston, a pressure-receiving surface which enables air pressure in the second output port to act on the pressure control piston, a cylinder chamber, a pressure control channel, and an elastic member which applies biasing force to the pressure control piston in a direction opposite to the action of air pressure on the pressure-receiving surface to determine pressure.

Abstract: A pneumatic control valve includes a first valve body, a pushing block, a rotating block, a second valve body, an end cover, and a piston. The first valve body defines a first gas inlet and a receiving hole. The first valve body forms a plurality of guiding ribs evenly positioned on the inner surface of the receiving hole away from the first gas inlet, and each of the guiding ribs forms an inclined surface at a distal end thereof. The pushing block and the rotating block are slidably received in the receiving hole. The second valve body is connected to an end of the first valve body adjacent to the receiving hole of the first valve body. The end cover is fastened on an end of the second valve body away from the first valve body. A pneumatic control system using the pneumatic control valve is also provided.

Abstract: A hydraulic control valve (10) provided with at least one body (11) having a jacket (12) with a feed orifice (13). The hydraulic control valve (10) has a transfer rod (15) provided with at least one fluid transfer duct (16), at least one orifice (17) present inside the jacket (12), and a second orifice (18) arranged outside the jacket (12). The jacket (12) has a feed chamber (25) connected to said feed orifice (13) and a main fluid-return chamber (30) connected to discharge means (50) for discharging the fluid, control means (20) being secured to the jacket (12) in order to move the jacket (12) in translation relative to said transfer rod (15) so as to control the flow of fluid within said transfer rod (15).

Abstract: A solenoid valve 10 including a valve sleeve 41, and a solenoid portion 20 which is mounted at one end along axial direction of the valve sleeve 41. A plurality of ports 51 to 54 are formed on the valve sleeve 41. In at least an outlet port 51 of the plurality of ports, a relation of S1?S0 is fulfilled, where S1 is an opening area of valve portion when the spool 60 moves in an axial direction to maximally open the valve portion between the outlet port 51 and the internal flow passage 47, and S0 is the total flow passage cross-sectional area.

Abstract: A solenoid device including pressure altering means for altering an output pressure of the solenoid device; and an actuator for providing an actuating signal to said pressure altering means; wherein the solenoid device further includes a sensor arranged to sense a control value of the solenoid device, and a controller which receives a request and is arranged to control delivery of power to the actuator with feedback from the sensor until the control value meets the request.