Abstract: A flow controller includes a flow detection unit that includes a detection unit for detecting the flow rate of a fluid; and a flow control unit that is coupled to the flow detection unit and that is capable of adjusting the flow rate of the fluid. The detection sensor constituting the detection unit includes a thermal flow sensor using MEMS technology, and the flow rate of the fluid that has been detected by the detection sensor is output to a control unit. In addition, in the flow control unit, the supply state of air to a supply room is switched by each of a supply-use solenoid valve and an exhaust-use solenoid valve, and on the basis of the supply state of the air, a control valve opens and closes.

Abstract: A liquid dispensing valve (12) including a liquid inlet (90) for receiving the liquid and a liquid outlet (92) for discharging the liquid. A valve member (44) is mounted for movement relative to the liquid outlet (92) between open and closed positions. A liquid passage (96) communicates between the liquid inlet (90) and the liquid outlet (92). An air inlet (114) is provided for receiving air from a source of pressurized air. An air passageway (120 and/or 128) is coupled with the air inlet (114). A pneumatic actuator (40, 110, 112) communicates with the air passageway (120 and/or 128) for moving the valve member (44) at least to the open position. An electrically operated air supply device (70) interacts with the air passageway (120 and/or 128) so as to control the flow of pressurized air to the pneumatic actuator (40, 110, 112).

Abstract: A pressure regulation circuit delivers pressurized fluid into a generator. The circuit includes pressure regulator structure and a primary valve. The pressure regulator structure outputs pressurized fluid at a predetermined output pressure that is greater than a desired operating pressure of the generator and less than a predetermined upper alarm pressure. The primary valve is downstream from the pressure regulator structure and is selectively opened and closed by a controller based on the pressure within the generator. The controller opens the primary valve to allow the pressurized fluid outputted from the pressure regulator structure to flow into the generator upon the pressure within the generator being at or below a predetermined lower limit. The controller closes the primary valve to prevent the pressurized fluid outputted from the pressure regulator structure from flowing into the generator upon the pressure within the generator being at or above a predetermined upper limit.

Abstract: A proportional motion control valve includes an electro-mechanical actuator that provides an infinitely controlled pressure setting in response to an electric signal applied to the electro-mechanical actuator. In another aspect, a proportional motion control valve includes a pilot-operated valve disposed intermediately with respect to a cage and a valve body to fluidly isolate an internal cavity of the valve body from a bore of the cage. The pilot-operated valve is subjected to a hydraulic opening force of pilot fluid that is present in the bore of the cage. A spring is disposed within the internal cavity of the valve body and arranged to subject the pilot-operated valve to a closing spring force.

Abstract: A stepper-motor gas valve control is disclosed that includes a main diaphragm in a chamber that controllably displaces a valve relative to an opening in response to changes in pressure, to adjust fuel flow through the valve. A servo-regulator diaphragm is provided to regulate flow to the main diaphragm, to thereby control the rate of fuel flow. A stepper motor is configured to move in a stepwise manner to displace the servo-regulator diaphragm, to control fluid flow to the main diaphragm. A controller mounted on the stepper-motor regulated gas valve control receives and converts an input control signal from a heating system to a reference value between 0 and 5 volts, and selects a corresponding motor step value. The control responsively moves the stepper-motor in a step wise manner to displace the servo-regulator diaphragm and thereby regulates the rate of fuel flow through the valve.

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 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: An irrigation valve has a valve body with an inlet passage, an outlet passage, and a valve seat intermediate the inlet passage and the outlet passage. A diaphragm includes a valve seat engaging portion that cooperates with the valve seat to control flow through the valve. The valve seat and the valve seat engaging portion of the diaphragm are offset relative to the inlet passage to improve flow through the valve to reduce pressure and energy loss.

Abstract: A subsea control module for subsea well equipment has an actuator having a rod with a remote operated vehicle (ROV) interface on one end and a latch on an opposite end that latches to a subsea receptacle. Segments are releasably mounted around and to the actuator. Each of the segments has a sealed housing containing at least one internal control component. Couplings depend from the housing for engaging mating couplings in the receptacle. The housing has two radial walls, each extending along a radial line from an axis of the rod. An outer wall joins outer ends of the radial walls, the outer wall being a portion of a cylinder. An inner wall joins inner edges of the radial walls. The radial walls of adjacent ones of the segments abut each other.

Abstract: In a electropneumatic field device, an electrical field input and a pneumatic supply input are provided. At least one field output is provided at which a field output signal is output based on a field control signal received via the electrical field input. A group comprising at least two modular components of different functionality is provided and at least one modular slot for occupation with either of said modular components from said group. The at least two modular components of the group and the at least one slot are modularly adapted to one another such that interfaces of the slot and interfaces of either of said modular components in the seat merge into one another when the slot is occupied with either of said modular components so that the modular component which is in the slot is connected to the electrical field input and to the at least one field output.

Abstract: A servovalve pilot stage (100) comprises a piezoelectric actuator (130) joined to a flow guide (132) and feedback wire (136) for connection to a main stage spool valve. The flow guide (132) and the piezoelectric actuator (130) may be integral.

Abstract: A valve is provided including a first valve member and a second valve member. The first valve member includes a first step and a first orifice adjacent the first step. The second valve member includes a second step and a second orifice adjacent the second step. The second valve member is movable relative to the first valve member between an open position, in which the first orifice is fluidly connected the second orifice, and a closed position, in which the first orifice is substantially fluidly disconnected from the second orifice. The first and second steps are fluidly connected to the second orifice and substantially fluidly disconnected from the first orifice when the second valve member is in the closed position, and the first and second steps are fluidly connected to the first and second orifices when the second valve member is in the open position.

Abstract: The present invention applies to a vacuum transfer system, and relates to an air control valve for controlling the supply of compressed air in a vacuum transfer system. More specially, the air control valve of the present invention is configured to execute a two-stage control. The two-stage control is realized by a piston operation method, in which, although the control is performed by compressed air supplied thereto, a first control unit is operated by an electronic control method, and a second control unit is operated by a pneumatic control method. In particular, the second control unit is operated by vacuum pressure supplied from the vacuum transfer system. The air control valve of this invention can realize improved operational stability, improved energy efficiency and improved operational precision.

Abstract: The invention relates to a proportional pressure-regulating valve (1) comprising a valve housing (3) that has at least three fluid-conducting connections, in particular in the form of a pump connection (P), a utility connection (A), and a tank connection (T). A regulating piston (5) is guided in a longitudinally displaceable manner within the valve housing (3) in order to selectively connect the pump connection (P) to the utility connection (A) and the utility connection (A) to the tank connection (T), said regulating piston being controllable via a magnetic force (FM) by means of a magnetic coil device (7) to which current signals can be applied.

Abstract: A hydraulic circuit for instant beverage machines includes a tank, a water extraction pipe contained in the tank, a flow-meter connected to the extraction pipe, a pump, a first vibration-damping valve, a boiler, a second relief and safety valve, a water/steam faucet, a third beverage flow valve, and a recovery tank.

Abstract: An adjustable damping valve arrangement comprises an actuator for controlling a main stage valve, wherein the main stage valve has a rigid main stage valve body which carries out an axial operating movement relative to a valve seat surface of the main stage valve, wherein a pre-opening valve having at least one spring element which in turn preloads a pre-opening valve body precedes the main stage valve body, wherein the main stage valve body is supported on the valve seat surface in the closed operating position by the pre-opening valve.

Abstract: An electronically actuatable valve assembly having a primary face seating valve, including a primary valve member, and a secondary valve, including a secondary valve member. The secondary valve opens before the primary valve to equilibrate pressure across the primary valve member and thereby facilitate opening of the primary valve member. The secondary valve is coupled to an armature which moves from a first position to a second position, in use, attracted by an electromagnet. The coupling between the armature and the secondary valve is configured to enable the armature to begin to move from the first position without movement of the secondary valve.

Abstract: An electronically actuatable valve assembly including a valve member comprising a ferromagnetic member, and a magnetic circuit adapted to direct magnetic flux through the ferromagnetic member when the valve member is spaced apart from its valve seat, to hold the primary valve open.

Abstract: A shut-off valve for opening and closing a cryogenic tank that has particular application for a hydrogen consuming system, such as a fuel cell system or an internal combustion engine. The shut-off valve is positioned in a supply line coupled to the cryogenic tank, and is opened by a control valve. When the control valve is actuated, hydrogen pressure from the supply line is used to open the shut-off valve. The control valve is coupled to the output line either upstream or downstream of the shut-off valve. An output of the control valve can be vented to a cathode input, an anode input or a cathode exhaust of a fuel cell stack, to an air input of an internal combustion engine or to ambient, depending on the particular application.

Abstract: The invention relates to a valve comprising a valve housing having a valve inlet and outlet, a valve seat arranged in the direction of flow of the fluid between the valve inlet and outlet, a closure means which is movably arranged in the valve housing, and has a first side and a second side, wherein the closure means closes off the valve seat tightly when the valve is in the closed state, a balancing opening for producing a pressure compensation between the first side and the second side of the closure means, and at least one control actuator, wherein the control actuator closes off the balancing opening of the closure means in a closed position and frees the balancing opening of the closure means in an open position so that the closure means frees the valve seat as a result of a pressure compensation via the balancing opening.

Abstract: A solenoid valve has a main stage and a pilot stage, wherein the main stage includes a switching element which in the closed condition of the solenoid valve closes a main flow path from a high-pressure side to a low-pressure side and in the open condition of the solenoid valve clears the main flow path. In its closed condition, the pilot stage closes a pilot flow path from the high-pressure side to the low-pressure side and in its open condition clears the pilot flow path. The pilot flow path leads through a control chamber which is in permanent flow connection with the high-pressure side via a control opening. The pressure existing in the control chamber acts on the switching element. The pilot stage includes a coil and a pilot valve element movable by a magnetic field of the coil, which are arranged at the switching element and are moved with the same.

Abstract: Systems and processes may provide field-initiated testing and/or control of fluid regulatory systems. In one aspect, a fluid regulatory testing system may include a field test initiator and a fluid regulator control system. The field test initiator may alter control signal delivered to the fluid regulator control system upon activation of a user input device. The fluid regulator control system may receive control signals from the field test initiator and generate fluid regulator control signals. The fluid regulator control system may also detect whether a control signal has been altered, and initiate a fluid regulator testing sequence, if the control signal has been altered. The fluid regulator control system may include a latch mode. When a latch mode is commenced, generation of fluid regulator control signals based on received control signals and/or alteration of a position of a fluid regulator may be inhibited.

Abstract: A high temperature servo valve to control a valve actuator for a valve body in a valve passage includes a plurality of high temperature wires to deliver a voltage; an actuator block of piezo ceramic material connected to the plurality of high temperature wires to move when it receives the voltage; a pressure supply line connecting the servo valve to the valve passage to supply air to the servo valve; a pressure vent line to vent pressure from the servo valve; and a pressure servo line connecting to the valve actuator to control the pressure in the valve actuator.

Abstract: An improved microvalve is described. The microvalve includes a corresponding actuation aperture in an actuation aperture layer. A control fluid flows through the actuation aperture. The flow of the control fluid is controlled by an electric field typically applied via a charge distribution near an actuation aperture layer. In one embodiment, the electric field may adjust the opening and closing of the actuation aperture thereby controlling the flow of the control fluid. In a second embodiment, the control fluid is an electrorheological fluid where the electric field controls the viscosity of the ER fluid thereby controlling fluid flow through the actuation aperture. In both embodiments the flow of the control fluid controls stretching of a flexible membrane formed along the wall of a conduit through which a fluid to be controlled flows. The stretching of the flexible membrane controlling the flow of the main fluid to be controlled.

Abstract: A valve and a hydraulic controller are provider. The valve may combine a rotary-to-linear converter with the hydraulic controller to provide for at least two mechanisms for actuating the valve. Additionally, the valve may include a mechanical lock mechanism suitable for securing the valve at a desired flow position. The mechanical lock mechanism may also provide overload protection. That is, the mechanical lock mechanism may “slip” or disengage if torque forces reach undesired levels. The hydraulic controller may enable a “stepping” mode of control and “fast actuation” mode of control. The “stepping” mode may deliver a discrete quantity of a fluid, while the “fast actuation” mode may deliver a continuous quantity of the fluid.

Abstract: A valve and a hydraulic controller are provider. The valve may combine a rotary-to-linear converter with the hydraulic controller to provide for at least two mechanisms for actuating the valve. Additionally, the valve may include a mechanical lock mechanism suitable for securing the valve at a desired flow position. The mechanical lock mechanism may also provide overload protection. That is, the mechanical lock mechanism may “slip” or disengage if torque forces reach undesired levels. The hydraulic controller may enable a “stepping” mode of control and “fast actuation” mode of control. The “stepping” mode may deliver a discrete quantity of a fluid, while the “fast actuation” mode may deliver a continuous quantity of the fluid.

Abstract: A compressed air supply system for a commercial vehicle includes a compressed air inlet that can be coupled to a compressor, a filter unit that is coupled to the compressed air inlet via a delivery line, a discharge valve unit that is coupled to a discharge outlet and the delivery line, an energy saving control output that can be coupled to a control input of the compressor, a first valve unit and a second valve unit, wherein the discharge value unit, the energy saving control output, and the regeneration of the filter unit can be controlled via the value units. A first control input of the discharge value unit, the energy saving control output and the regeneration of the filter unit can be controlled via the first value unit. A second control input of the discharge value unit can be controlled via the second value unit. A method is provided for operating the compressed air supply system.

Abstract: A device has been disclosed that may include a spool valve including a body having a first connector and a second connector and a spool movable relative to the body for controlling flow between the first connector and the second connector. The reversible flow control assembly further may include a pilot valve device developing a single pressure command in the form of a fluid at a command pressure. The spool valve may be responsive to the single pressure command developed in said pilot valve device to control flow between the first connector and the second connector without regard to the direction of flow. The majority of axial forces acting on the spool to position the spool relative to the body when fluid is flowing through the valve may be fluid forces.

Abstract: A selector valve operating mechanism is provided with operating pistons which are hydraulic pistons connected through an operation link to a spool of a PTO selector valve, an solenoid valve for hydraulically controlling reciprocation of the operating pistons, and a controller which is a control device for transmitting an operation signal to the solenoid valve. Control of operation of the solenoid valve moves the spool through the operating pistons and the operation link to switch the PTO selector valve.

Abstract: A valve (10) includes a first valve housing portion (12) and a second valve housing portion (14). The first valve housing portion and the second valve housing portion are separate components attached together to define a valve housing. The first valve housing portion includes an inner end surface (16) having an opening (18). The second valve housing portion includes an inner end surface (56) having a protruding annular rim (60) with an annular groove (62) and a seal (64) is received in the annular groove. The protruding annular rim including the seal is received in the opening in the inner end surface of the first valve housing portion to define a valve housing.

Abstract: A compressed air supply system for a utility vehicle includes a compressed air inlet that can be coupled to a compressor, a filter unit that can be coupled to the compressed air inlet via a supply line, a discharge valve element that is coupled to a discharge outlet and the supply line, an energy-saving control outlet that can be coupled to a control inlet of the compressor, a supply line locking valve element interposed between the compressor and the filter unit and a first valve element and a second valve element, the discharge valve element, the energy saving control outlet, the regeneration of the filter unit and the supply line locking valve element being controllable by the valve elements. The energy saving control outlet can be controlled by the first valve element and the discharge valve element and the regeneration of the filter unit can be controlled by the second valve element.

Abstract: A solenoid on-off valve includes a main valve body in a housing. A pilot passage is formed on the main valve body, and a pilot valve body is inserted into the pilot passage so as to open and close the pilot passage. The pilot valve body and the main valve body move in accordance with a plunger which is movable in an opening direction. The plunger and the pilot valve body are coupled by a coupling pin. The coupling pin is displaceable relative to the pilot valve body. When the main valve body is pushed in the opening direction and before the coupling pin contacts the pilot valve body, the plunger stops the movement of the main valve body. Thus, a shear force is prevented from acting on the coupling pin when the valve port is opened.

Abstract: Fail-safe apparatus for use with fluid valves are disclosed herein. An example fail-safe apparatus includes a first piston, a second piston movably coupled relative to the first piston, and a fluid chamber between the first and second pistons to receive a control fluid. The control fluid is to operatively couple the first and second pistons when the control fluid is provided in the fluid chamber. The first piston is operatively decoupled from the second piston when at least some of the control fluid is removed from the fluid chamber.

Abstract: A stepper-motor gas valve control is disclosed that includes a main diaphragm in a chamber that controllably displaces a valve relative to an opening in response to changes in pressure, to adjust fuel flow through the valve. A servo-regulator diaphragm is provided to regulate flow to the main diaphragm, to thereby control the rate of fuel flow. A stepper motor is configured to move in a stepwise manner to displace the servo-regulator diaphragm, to control fluid flow to the main diaphragm. A controller mounted on the stepper-motor regulated gas valve control receives and converts an input control signal from a heating system to a reference value between 0 and 5 volts, and selects a corresponding motor step value. The control responsively moves the stepper-motor in a step wise manner to displace the servo-regulator diaphragm and thereby regulates the rate of fuel flow through the valve.

Abstract: A fluid-operated actuator assembly has a valve with an inlet for connection to a pressurized fluid source, a bi-stable electromagnetic device for operating the valve, which has a first state closing the valve and a second state opening the valve, a hydraulic actuator, and an electronic control circuit. The hydraulic actuator has an actuating member in a housing, the housing having a chamber on one side of the actuating member to which an outlet of the valve is connected for receiving fluid from the fluid source when the valve is opened, the actuating member for operation of the hydraulic actuator. The control circuit momentarily energizes the bi-stable electromagnetic device to the hydraulic actuator from the second state, back to the first state, to terminate operation of the hydraulic actuator.

Abstract: A solenoid operated pilot valve utilizes an offset pilot opening and a lever arm to provide a mechanical advantage to multiply the opening force of the solenoid, thereby allowing the solenoid size to be reduced. The lever arm used to position the pilot valving member is mechanically positioned via a solenoid driven plunger in one embodiment, and is positioned by magnetic force alone in an alternative, plungerless embodiment. The lever arm pivots via a fixed fulcrum point, a profiled fulcrum providing continuously variable mechanical advantage, or a stepped fulcrum providing discreet different mechanical advantages as the pilot valving member is moved from its fully closed to its fully opened position.

Abstract: The disclosure relates to a method and device for operating an electropneumatic valve for driving a pneumatic actuator drive to activate fittings in automation systems. The valve has at least one electropneumatic transducer and a pneumatic booster. The pneumatic booster has at least one 3/3 way valve with a blocking center position for optionally connecting an air inflow duct or an air outflow duct to a connecting duct, which connects to the actuator drive. The ducts are activated as a function of an electrical actuation signal by the electropneumatic transducer. At least one position of the 3/3 way valve with a blocking center position is measured and a correction value of a variable of the actuation signal is determined based on the measured value and the electrical actuation signal.

Abstract: A solenoid valve assembly capable of providing a continuous flow of pressurized inert gas to operate a process tool without interruption. A system comprising the solenoid valve assembly is also provided.

Abstract: The invention relates to a valve comprising a valve housing having a valve inlet and outlet, a valve seat arranged in the direction or flow of the fluid between the valve inlet and outlet, a closure means which is movably arranged in the valve housing and has a first side and a second side, wherein the closure means closes off the valve seat tightly when the valve is in the closed state, a balancing opening for producing a pressure compensation between the first side and the second side of the closure means, and at least one control actuator, wherein the control actuator closes off the balancing opening of the closure means in a closed position and frees the balancing opening of the closure means in an open position so that the closure means frees the valve seat as a result of a pressure compensation via the balancing opening

Abstract: A fluid-operated actuating drive on a valve comprising a base unit (2) having an electro-fluidic signal converter and a fluidic controller and at least one linear actuator (4) that can be actuated using the fluidic controller, wherein the gate (11) of the linear actuator is directly or indirectly coupled to the inlet of the valve. A control unit (22) is connected to a signal input of the base unit, wherein the signal output is connected to the electro-fluidic signal converter. The actual value signal of a measurement transducer (24) associated to the valve is fed back to the control unit. A fluidic internal control circuit (27) is arranged functionally between the signal input and the at least one linear actuator, preferably downstream of the electro-fluidic signal converter.

Abstract: The inventive technology, in embodiments, may include a controller configured to coordinate operation of valves and remotely controllable regulators that are fluidically communicative therewith, allowing the control of positioners of positioner zones that are fluidically communicative with such remotely controllable regulators. Preferred embodiments may find application as, e.g., a pneumatic system to control positioners, whether such positioner find use in bottling applications or elsewhere. Additional aspects of the inventive technology may relate to methods for pressurized fluid positioner control.

Abstract: A high-pressure fuel injection valve may include a control valve having an actuator, a high-pressure fuel connection and a low-pressure fuel connection. A control plunger and nozzle needle are aligned longitudinally in the valve stem and the valve tip. Together with the control plunger, the receiving chamber of the control plunger forms a closing control chamber delimited by the upper control plunger surface, and an opening control chamber delimited by the lower control plunger surface. Each control chamber is hydraulically connected via a feed throttle to the high-pressure fuel connection and via a return throttle to the low-pressure fuel connection. The control valve opens and closes the fuel return between the return throttles and the low-pressure fuel connection depending on the operation. The flow values of the feed throttles and of the return throttles are selected such that the high-pressure fuel injection valve opens and closes based on actuation of the control valve.

Abstract: A valve includes a housing defining a bore having an inlet and extending along a longitudinal axis. A head is attached to the housing and defines a head passage having an outlet. A piston is disposed within the bore and includes a piston passage extending through the piston along the longitudinal axis. The piston is moveable between a closed position in which a sealing end of the piston abuts a seat of the head to close fluid communication through the piston passage and an open position in which the sealing end of the piston is axially spaced along the longitudinal axis from the seat of the head to permit fluid communication through the piston passage between the inlet and the outlet. The housing defines an equalizing chamber in fluid communication with the head passage for damping movement of the piston.

Abstract: The invention refers to an electro-magnetic pressure control valve with a magnetic part and a valve part. The magnetic part has at least on coil that can be electrically triggered, a coil core and an armature guided traversingly. The valve part has a feed for the pressurized medium, a return and a consumer connection. The valve part has at least two seat valves that can be closed each by a valve element.

Abstract: A hydraulic housing of an electrohydraulic valve controller of an internal combustion engine which has a hydraulic housing body and guide cylinder for a pump piston that is joined to the hydraulic housing body. The guide cylinder is joined to the hydraulic housing body by a friction welded connection.

Abstract: The invention relates to a valve device comprising a valve housing (2) and a valve piston (4) arranged in an axially displaceable manner in a piston bore (3) of the valve housing (2), via which valve piston a first load connection (A) and a second load connection (B) can alternately be connected to a pressure connection (P) and to a tank connection (T1, T2) by the action of a first solenoid magnet (5) and a second solenoid magnet (6), a pilot control unit (7) being provided, which comprises a first pilot control chamber (8) that pressurizes a first piston back side (9) of the valve piston (4) and a second pilot control chamber (10) that pressurizes a second piston back side (11) of the valve piston (4), the first and second pilot control chambers (8, 10) being connectable via a respective fluid-conducting connection (12, 13) to the pressure connection (P), a first pilot control piston (14) and a second pilot control piston (15) being provided, which release or close a fluid-conducting connection (16, 17) betw

Abstract: A compressed air supply system and method of operating same for a commercial vehicle includes a compressed air inlet that can be coupled to a compressor, a filter unit that can be coupled to the compressed air inlet via a supply line, a discharge valve element that is coupled to a discharge outlet and the supply line, a first valve element and a second valve element. A control inlet of the discharge valve element is controllable by the first valve element and the second valve element is arranged in a regeneration air path for regenerating the filter unit. At least one pneumatically lockable overflow valve via which a consumer circuit coupled to the compressed air supply system is supplied with compressed air. The at least one pneumatically lockable overflow valve can be controlled by the second valve element.

Abstract: A directly piloted valve assembly has a valve body including a bore, at least one inlet port, at least one outlet port and at least one exhaust port or second outlet port wherein the ports are all in fluid communication with the bore. A spool is received in the bore. The spool includes a wall defining a lumen. An actuator is received in the lumen. The actuator includes a shuttle seal channel. A shuttle seal is received in the shuttle seal channel. A solenoid is connected to the valve body. The wall of the spool includes at least one pilot hole in fluid communication with the lumen defined by the spool and the bore of the valve body.

Abstract: Example methods and apparatus to arbitrate valve position sensor redundancy are disclosed. A disclosed example method comprises measuring a first value representative of a position of a valve, measuring a second value representative of the position of the valve, computing a first estimated position of the valve, selecting one of the first and second values based on the first estimated position, and generating a first valve control signal for the valve based on the selected one of the first and second values.

Abstract: A multiple-stage valve system (200) including a pilot fluid supply (209) and a process fluid supply (222) is provided. The multiple-stage valve system includes a first pilot valve (201) including a first port (206) in fluid communication with the pilot fluid supply and a second port (207) selectively in fluid communication with the first port. The multiple-stage valve system also comprises a second pilot valve (202). The second pilot valve can include a first port (213) in fluid communication with the process fluid supply and a second port (214) selectively in fluid communication with the first port. The second pilot valve also includes a first pressure-actuated biasing member (217) in fluid communication with the process fluid supply and a second pressure-actuated biasing member (218) in fluid communication with the second port of the first pilot valve. The multiple-stage valve system also comprises a main control valve (203).

Abstract: A controller for a variable heating system is operable to control a stepper motor operated gas valve to adjust gas flow to vary the heating level. The controller includes a first terminal for receiving a thermostat signal requesting heating, an electronic memory, and a microprocessor in communication with the electronic memory and first terminal. The microprocessor detects a thermostat signal requesting heating, and generates a control signal for the stepper motor to operate the gas valve. The microprocessor includes a programmable read-only-memory encoded with an instruction to store a time duration during which the microprocessor detects a thermostat signal requesting heating, and further encoded with an instruction operable to determine a predetermined heating level based on the stored time duration. The microprocessor responds to a thermostat signal requesting heating by determining the number of steps the motor must move to vary the gas flow corresponding to the predetermined heating level.