Abstract: A solenoid valve includes: a valve housing having, at one end thereof, an inlet port through which a fluid is introduced and having, at the other end thereof, an outlet port through which the fluid is discharged; a solenoid provided in the valve housing and disposed between the inlet port and the outlet port; a first plunger provided at one end of the solenoid adjacent to the inlet port and configured to selectively open or close the inlet port by being rectilinearly moved by the solenoid; a first spring member configured to provide elastic force to allow the first plunger to move in a direction in which the first plunger closes the inlet port; a second plunger provided at the other end of the solenoid adjacent to the outlet port and configured to selectively open or close the outlet port by being rectilinearly moved by the solenoid in a direction opposite to the movement direction of the first plunger; and a second spring member configured to provide elastic force to allow the second plunger to move in a dir

Abstract: A vent valve flow fuse includes a valve cap with a valve cap cavity defined by one or more valve cap interior surfaces. The vent valve flow fuse includes a valve body with a valve body cavity defined by one or more valve body interior surfaces. The vent valve flow fuse includes a poppet configured to at least partially fit within the valve cap cavity and the valve body cavity. The vent valve flow fuse includes a spring configured to fit within the valve body cavity and to generate a resistive force against the poppet. The poppet is in a first position when fluid having a first amount of fluid pressure enters the valve cap cavity from a vent valve and engages the poppet. The poppet is in a second position when fluid having a second amount of fluid pressure enters the valve cap cavity and engages the poppet.

Abstract: Methods for providing at least one product stream, in particular hydrogen, by electrolysis by means of an electrolyzer having a multiplicity of electrolysis cells combined to form at least one framework; wherein electrolyte is discharged from the cells and separated into two phases. The electrolyte is collected upstream of a pump system. At least the functions of discharge and collection are carried out integrally together in a multifunctional collection container or in an integral method step, in particular by means of at least one multifunctional collection container with a regulatable filling level coupled to the cells. This extends the functionality and also provides an advantageous design construction. The invention furthermore relates to a corresponding electrolysis device and to a corresponding multifunctional collection container.

Abstract: An adjustable pressure valve has a valve body, an inactive cap and an active cap. The inactive cap is mounted in the outlet of the valve body, abuts against the piston in the valve body and has an inclined edge. The active cap is mounted rotatably against the inactive cap and has an inclined edge abutting against the inclined edge of the inactive cap. When the active cap is rotated relative to the inactive cap, the inactive cap is pushed by the inclined edge of the active cap to slide inwardly or outwardly. Then the elastic element in the valve body is compressed more or less by the slide of the active cap to adjust the preset outlet pressure without disassembling the adjustable pressure valve.

Abstract: A fuel system which includes a fuel return system. The fuel return system includes a fuel return valve arranged on a return line, and the return line is intended to be mounted between an engine of an aircraft and a fuel tank of the aircraft. The return valve is configured to allow a return of fuel from the engine to the fuel tank when the engine is in operation. The fuel return system also includes a bypass valve assembly mounted in parallel to the return valve, and is configured to allow a return of fuel from the engine to the fuel tank when the engine is not in operation.

Abstract: An expansion valve (1) for a vapor compression system, the valve (1) comprising a first valve part (5) having an outlet orifice (7) and a piston (8) movable inside the outlet orifice (7) in response to a differential pressure across the expansion valve (1), controlling a fluid flow through the valve (1). The piston (8) comprises a stop element (9) at an outlet end (8b) of the piston (8) and mechanical forcing means (10) to force the piston (8) towards a position in which the stop element (9) is brought into abutment with a valve seat (12) of the first valve part (5). A differential pressure below a predefined threshold value causes the stop element (9) of the piston (8) to abut the valve seat (12) of the first valve part (5), preventing fluid flow through the first valve part (5), via the forward fluid passage.

Abstract: Provided is a flow rate adjustment device including: a valve body portion configured to be movable along an axis line; a body portion having a valve bore and an upstream-side fluid chamber formed therein, the valve body portion being inserted into the valve bore, the upstream-side fluid chamber being configured to circulate a fluid; and a thin film-like first diaphragm portion which is coupled to the valve body portion and configured to isolate the upstream-side fluid chamber from a spring accommodation chamber adjacent to the upstream-side fluid chamber. The first diaphragm portion is formed of a conductive fluororesin material including a fluororesin material and carbon nanotubes dispersed in the fluororesin material, and the conductive fluororesin material has a volume resistivity of more than 1.0×103 ?·cm and less than 1.0×104 ?·cm.

Abstract: A refrigerant supply device with a small lateral width and a capacity to supply refrigerant evenly among heat receivers disposed in multiple tiers needs to be provided. A refrigerant supply device for distributing, by force of gravity, liquid phase refrigerant to heat receivers disposed in a plurality of tiers includes: a first conduit for supplying the refrigerant to the heat receivers; a second conduit provided in parallel with the first conduit; a first aperture provided in the first conduit for supplying the refrigerant to one of the heat receivers; a first blocking means provided below the first aperture for blocking the first conduit; a first communication opening provided above the first aperture and communicating the first conduit and the second conduit; a second communication opening provided below the first blocking means and communicating the first conduit and the second conduit; and a second blocking means provided below the second communication opening for blocking the second conduit.

Abstract: A membrane restrictor adapted to be connected to a pump and a bearing is provided. The pump is adapted to supply fluid to a location between the bearing and the rail through the membrane. The bearing is adapted to be disposed on a rail. The membrane restrictor includes a casing and a membrane. The casing has a chamber, an inlet and an outlet communicating with each other through the chamber, and a restricting plane. The pump is adapted to be connected to the inlet; the bearing is adapted to be connected to the outlet. The membrane is disposed in the chamber. The restricting plane is an inner surface of the casing adjacent to the outlet and towards the membrane. Dimensionless stiffness of the membrane is Kr*, and 1.33?Kr*?2. Kr*=KrL0/(psAr). Here, Kr is stiffness of the membrane, L0 is a distance from the membrane to the restricting plane when no fluid is supplied by the pump (i.e., assembling clearance of the membrane), ps is pressure supplied by the pump, and Ar is an effective area of the restricting plane.

Abstract: Aqueous compositions contain hydrochloric acid at a concentration between 8 wt % and 28 wt % inclusive. The amino acid; hydrochloric acid mole ratio may be between 0.2 and 1.5. Sufficient water is present to dissolve the hydrochloric acid and the amino acid. Such compositions have utility as retarders for acid compositions employed in the stimulation of subterranean formations. Slowing the reaction between the acid and formation helps maximize formation permeability and productivity.

Abstract: A kneading device includes: a preliminary kneading device that produces a preslurry by agitating a powder and a liquid introduced and transferring them while wetting the powder with the liquid; and a main kneading device that causes the powder to be uniformly dispersed in the preslurry supplied from the preliminary kneading device to produce a slurry. The main kneading device includes a gap defined by two conical surfaces that face each other with a predetermined distance therebetween and rotate relative to each other about their central axes. The slurry is produced by passing the preslurry through the gap. With the preliminary kneading device, the powder is dispersed in the liquid after conforming to the liquid, which suppress damage to the powder. The conditions of main kneading can be changed only by adjusting the gap, which facilitates the operation of changing the conditions of the main kneading.

Abstract: The invention provides a method for enriching diluents with butane so as not to violate pre-defined limits for liquid hydrocarbon fuels with respect to density, volatility and low density hydrocarbon content.

Abstract: An apparatus is supplied for a self adjusting regulator suited for an irrigation emitter. A curved flow channel is integrated into a concave dome shaped surface. A deformable member deforms to approach the surface to adjust the resistance to flow. The concave dome shaped surface may match a deformed shape of the membrane. Irregularities in the interface between the surface and the deformable member are configured to achieve a desired discharge under varying flow conditions. The deformable member may activate an inlet filter cleaner by pushing a ram and thereby unclogging the filter.

Abstract: A flow control valve has a valve body part which has a pressure differential device part and a valve seat, a first diaphragm which defines first and second chambers, a second diaphragm which defines third and fourth chambers and is provided with a valve element, a first moving part which advances and retracts together with the first diaphragm, and a second moving part which advances and retracts together with the second diaphragm; the second chamber and the fourth chamber form between them a connecting chamber, an intermediate transmission member which transmits movements of the first and second moving parts to each other is arranged, and a pressure differential control valve element which advances and retracts with respect to the pressure differential opening part and a pressure differential control valve element advancing/retracting means for making the pressure differential control valve element advance and retract are provided, and a flow control system using the same.

Abstract: The invention concerns a flow regulator, made of a stack of 3 plates, respectively a top plate including a flexible membrane (1), a middle plate (2) with pillars and through holes and a bottom plate (3) with fluidic ports, micro channels and through holes (8,9,12). The principle is based on the deformation of the membrane due to the pressure of the liquid. The membrane goes in contact with the pillars of the middle plate, obstructing gradually the through holes of the pillars. The device is designed to keep the flow constant in a predefined range of pressure. The device is dedicated to ultra low flow rate up to 1 ml per day or below, typically for drug infusion. Plastic flow regulators comprise preferably several independent valves coupled in parallel. The membrane plate is therefore made of several flexible membranes obstructing gradually the flow by increasing the pressure. Stress limiters are used to avoid plastic deformation of the membrane.

Abstract: The invention relates to a valve combination for regulating the rate of flow or the differential pressure in liquid-conveying heating and cooling systems, consisting of a housing (2) provided with a feed pipe (10), a discharge pipe (11) and a connection pipes (6) arranged between them and a regulator (3) which is arranged axially in the connection pipe (6), wherein the regulator (3) keeps the differential pressure constant at a preset value by means of a first flow regulator (4) also arranged axially in the connection pipe (6) and can be adjusted by an actuating part (8) which projects from the housing (2) and acts on a second seat (24), and by means of a presettable second flow regulator (5) which is arranged axially or coaxially thereto, wherein the flow cross section (9) is adjustable, which is characterized in that, when an actuator (29) that acts on the actuating part (8) is installed, the flow cross section (9) is adjustable by means of a handle (7) not covered by the actuator and that, when the actuato

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

Abstract: A typical flow-control valve has a housing forming a flow passage and a valve seat. An upstream and downstream valve bodies are is engageable with the seat and form upstream and downstream restrictions. A control piston defines therein outer and inner control compartments. This control piston is coupled to the downstream valve body for joint movement therewith. High-pressure and low-pressure conduits connect the outer and inner control compartments to the flow passage upstream of the upstream restriction and to the flow passage between the upstream and downstream restrictions. A connector element or stem connected to the upstream valve body extends through the control piston and has an outer end projecting out of the housing. A pressure reliever between the control piston and the outer end exerts on the connector element a force urging the upstream valve body upstream and generally equal to a pressure differential across the upstream restriction.

Abstract: A fluid flow regulator includes a regulating profile which is either centrally or peripherally disposed within the flow rate regulator, and an annular restrictor which is made of an elastic material. In a functional position of the flow rate regulator, the restrictor delimits a control gap between itself and the regulating profile. In a starting position of the flow rate regulator, the flow rate regulator has an unrestricted flow cross section that is larger than the control gap. The unrestricted flow cross section of the flow rate regulator is variable by a deformation of the restrictor in response to a pressure differential that is generated when a fluid flows through the flow rate regulator. The relative position of the restrictor and the regulatory profile is variable, and moveable against a reset force, into the functional position from the starting position, in response to a flow of fluid within the flow rate regulator. The reset force may be provided in the form of a spring.

Abstract: A constant flow rate valve has a housing in which a rotatable sleeve is positioned between the valve's inlet and outlet. Apertures in the sleeve move into alignment with the valve's inlet and outlet upon sleeve rotation to establish the fluid flow rate. A piston is movable longitudinally within the sleeve bore. The piston has openings which align with the apertures in the sleeve upon longitudinal motion of the piston. Pressure ducts connect each end of the sleeve to the inlet and outlet. The piston moves in response to relative pressure changes in the inlet and outlet communicated by the pressure ducts. The area of overlap between the piston's openings and the sleeve's apertures varies with piston motion to ensure a constant flow rate in spite of relative inlet and outlet pressure changes. The ends of the sleeve are in fluid communication to control the response sensitivity of the piston.

Abstract: An object of the present invention is to provide a constant flow valve able to make the flow rate constant at all times even if the upstream and downstream side fluid pressure of the valve fluctuates for a large flow rate fluid and able to set the flowing fluid to any flow rate.

Abstract: A constant flow rate valve has a housing in which a rotatable sleeve is positioned between the valve's inlet and outlet. Apertures in the sleeve move into alignment with the valve's inlet and outlet upon sleeve rotation to establish the fluid flow rate. A piston is movable longitudinally within the sleeve bore. The piston has openings which align with the apertures in the sleeve upon longitudinal motion of the piston. Pressure ducts connect each end of the sleeve to the inlet and outlet. The piston moves in response to relative pressure changes in the inlet and outlet communicated by the pressure ducts. The area of overlap between the piston's openings and the sleeve's apertures varies with piston motion to ensure a constant flow rate in spite of relative inlet and outlet pressure changes. The ends of the sleeve are in fluid communication to control the response sensitivity of the piston.

Abstract: A water spray nozzle assembly includes an internal channel that is sealable by an internal valve having a seat and a disc. A tilting member is operable to tilt the disc at least partially off of the seat, allowing water to flow through the internal channel. The disc may be further tilted completely off of the seat to provide additional water flow through the water spray nozzle.

Abstract: An insert for being mounted in a valve housing (80) or a tubular member for dynamic flow control of a flowing medium. The insert comprises:—a first cup-shaped part (1) provided with an outflow area;—a second cup-shaped part (10) arranged axially displaceably within the first cup-shaped part (1) and provided with an inflow area;—a pressure spring (30) arranged for exerting a force (F) that seeks to force the two cup-shaped parts (1, 10) away from each other. The second cup-shaped part (10) is configured such in relation to the first cup-shaped part (1) that the inflow area of the first cup-shaped part (1) is closed in response to a displacement of the second cup-shaped part (10) in relation to the first cup-shaped part (1).

Abstract: A normally closed regulator valve for controlling the pressure of flowing fluid and also for selectively fully enabling or stopping the flow. The regulator valve includes a valve housing having an inlet passage and an outlet passage connected by a flow passage with a seat surrounding the flow passage. A valve member is movable toward and away from contact with the seat. A control housing is attached to the valve housing. An elongated rod connected at one end to the valve member has an opposite end extending into the control housing. A rod partition, which may take the form of a rigid piston or a flexible diaphragm, is connected to the opposite end of the elongated rod and is movable in the control housing in sealing relation with the walls thereof. A compression spring is provided to bias the rod partition and the valve member in directions either toward or away from sealing engagement with the flow passage seat.

Abstract: A metering unit for metering liquid and/or gaseous educts by means of a feed pump for a fuel cell system, including at least one lead line for delivering an educt flow, at least one control piston, and a differential pressure valve for regulating the educt flow; the differential pressure valve has a regulatable throttling cross section, which is variable automatically, as a function of a flow pressure dictated by the control piston, in order to regulate the educt flow. The lead line leads to the control piston, and between the control piston and the differential pressure valve a first and a second connecting line are provided.

Abstract: A fuel metering unit including a pump having a rotor with a plurality of slots. The pump also includes a pivotally movable cam ring coaxially arranged with respect to the rotor. Vanes are slideably disposed in the slots for maintaining contact with the cam ring during movement thereof. A servovalve has a motor and nozzles operatively connected to the pump such that increased flow through the first nozzle pivots the ring of the pump toward maximum while increased flow through the second nozzle pivots the ring toward minimum. An arm extends between the nozzles for varying fluid flow therethrough. The arm couples to the motor such that the motor moves the arm. A flow meter connects to the pump and an end of the arm for applying a force against the arm to assist in maintaining position of the arm.

Abstract: A constant gas flow regulating device includes an inlet chamber, an outlet chamber and a movable wall that delimits the inlet and outlet chambers from each other. The moveable wall carrics a body comprising an opening that permits communication between the inlet and outlet chambers. An elongate element extends centrally in the opening of the body in the moving direction of the wall. The opening within the body surrounds a portion of the elongate element. In a first position the opening in the movable wall is placed in the vicinity of a first end of the elongate element. The element has a sectional size that gradually increases from the first end to a second end thereof. The size of the opening in the movable wall is larger than the sectional size of the elongate element. A helical spring biases the movable wall towards a first position.

Abstract: A device for regulating the flow of gas from an environment. The device includes a shell forming a path through which fluid flows. A fixed grate is disposed in the path so that as fluid flows in the path the fixed grate does not move. A movable grate assembly includes one or more plates and a movable grate attached to the one or more plates. The one or more plates includes an integral hinge such that the plate can rotate about the integral hinge. When the movable grate moves with respect to the fixed grate the impedance on the flow varies.

Abstract: According to one aspect of the invention, a fluid regulating control valve includes a housing having an upstream region and a downstream region and having a control orifice formed therein adjacent the downstream region and a piston slidably disposed within the housing. The piston has a fluid passage defining an intermediate region disposed between the upstream region and the downstream region and an edge adjacent the downstream region. The valve also includes an elastic member disposed within the housing for opposing translation of the piston within the housing and a throttling element adjacent the upstream region. The throttling element has a throttling surface adjacent the edge of the piston, in which the throttling surface and the edge define a throttling orifice therebetween.

Abstract: A fuel metering unit including a pump having a rotor with a plurality of slots. The pump also includes a pivotally movable cam ring coaxially arranged with respect to the rotor. Vanes are slideably disposed in the slots for maintaining contact with the cam ring during movement thereof. A servovalve has a motor and nozzles operatively connected to the pump such that increased flow through the first nozzle pivots the ring of the pump toward maximum while increased flow through the second nozzle pivots the ring toward minimum. An arm extends between the nozzles for varying fluid flow therethrough. The arm couples to the motor such that the motor moves the arm. A flow meter connects to the pump and an end of the arm for applying a force against the arm to assist in maintaining position of the arm.

Abstract: A fuel metering unit including a pump having a rotor with a plurality of slots. The pump also includes a pivotally movable cam ring coaxially arranged with respect to the rotor. Vanes are slideably disposed in the slots for maintaining contact with the cam ring during movement thereof. A servovalve has a motor and nozzles operatively connected to the pump such that increased flow through the first nozzle pivots the ring of the pump toward maximum while increased flow through the second nozzle pivots the ring toward minimum. An arm extends between the nozzles for varying fluid flow therethrough. The arm couples to the motor such that the motor moves the arm. A flow meter connects to the pump and an end of the arm for applying a force against the arm to assist in maintaining position of the arm.

Abstract: A regulating insert for mounting in valves includes a dynamically flow regulating body, with the body having a first housing that is disposed within a second housing. A coil spring is arranged about an axis thereof, and a first end of the coil spring engages a slidable bottom cup provided with at least one inlet opening for liquid in its wall. The opening has an adjustable flow area. The second end of the coil spring opposite the first end engages a partly closed end of the second housing. The partly closed end has a cylindrical opening that provides a seat for a valve cone situated within the second housing. The position of the valve cone is regulated by first means via an activation means.

Abstract: A device for igniting fuel, comprising at least one burner, the device comprising ignition means comprising an ignition element, the ignition means further comprising a movable element which is connected to a fluid line, such that a fluid contained in the fluid line, when it flows, creates a pressure difference across the movable element, as a result of which the movable element is set in motion, the movable element being connected with the ignition element, such that the movement of the movable element generates via the ignition element and ignition temperature by means of which the fuel is caused to combust.

Abstract: A helical flow compressor used to supply gaseous fuel to a turbogenerator is equipped with an inlet throttling valve. The inlet throttling valve maintains the outlet pressure of the compressor at a preselected value.

Abstract: A controller for controlling a medium flow fed from a supply to at least one hydrostatic or aerostatic pocket of a bearing, a threaded spindle nut or a guide, having a housing and having pressure chambers which are separated by a control element, movable against the force of a spring element, and of which a first pressure chamber, subjected to a first pressure level, is directly connected to the medium supply, a second pressure chamber, subjected to a lower, second pressure level, is connected to the medium supply via a first flow resistance, and a third pressure chamber, which is subjected to a third pressure level which corresponds to that in the pocket, is connected to the pocket, a control element forming a variable second flow resistance is arranged between the second and third pressure chambers influencing the medium flow to the pocket and whose magnitude is raised by the action of the force of the first pressure chamber but is lowered by the action of the spring force and by the actions of the forces o

Abstract: There is provided in accord with the present invention a work vehicle having a transmission and a clutch control system controlling the vehicle clutches, with the clutch control system including a flow restrictor assembly. The flow restrictor assembly comprises a modulator valve and an unloading valve in fluid communication with the fluid supply and the clutch control system. The unloading valve is selectively in fluid communication with the modulator valve through a modulator tank orifice and is responsive to fluid pressure changes acting on the modulator valve, as the clutch control system operates to control the length of time the modulator valve regulates the rate of flow of fluid to the clutch control system through the modulator tank orifice. In one embodiment the unloading valve spool is nested inside the modulator valve spool.

Abstract: A fluid flow fuse has a body, which includes an inlet and an outlet with a valve seat therebetween. A valve stem having a valve member thereon is mounted in the body, and the valve member is operably connected to a diaphragm, which separates a region within the body into a pair of separate pressure chambers. Fluid passages are formed in the body communicating the separate pressure chambers with downstream pressure from the outlet and upstream pressure from the inlet. The pressure differential between the chambers is minimized so that at least one spring will normally hold the valve member in an open position, until the pressure differential reaches a predetermined amount, whereby the valve member is slowly and smoothly closed until fluid flow through the fuse is stopped.

Abstract: The flow control valve (10) has a body (11) and a valve mechanism (40). The body defines a chamber (20). The chamber involves an inlet (12) for receiving fluid to control, a valve seat (16) for passing the fluid, and an outlet (15) for discharging the fluid. The valve mechanism consists of a valve plug (41) for opening and closing the valve seat, a first diaphragm (50) arranged in the vicinity of the inlet, and a second diaphragm (60) arranged in the vicinity of the outlet. Each of the diaphragms is in the chamber and has a periphery fixed to the body. The diaphragms divide the chamber into a first pressure chamber (21) outside the first diaphragm, a valve chamber (25) between the diaphragms, and a second pressure chamber (30) outside the second diaphragm. The valve chamber includes the inlet, valve seat, and outlet.

Abstract: A device for limiting the flow rate of a fluid through a conduit operates autonomously without any external energy source, and independently of the level of pressure upstream, by operating on an imposed upstream-downstream pressure difference. The flow limiter is capable of limiting the rate of flow of a fluid through a pipe, the flow rate of the fluid depending on the cross section for passage of the fluid in the pipe, and on the difference between the upstream and downstream pressures relative to the passage cross section, in the direction in which the fluid flows.

Abstract: A fuel filter for a fuel dispensing pump comprises a shell having a closed end and an open end. A plate is fixed in the open end of the shell. The plate has one or more fuel inlet openings and a centrally located fuel outlet opening. A rigid annular pervious core in located within the shell. A water absorbing media is disposed about the core. A first end cap closes the inner end of the core and the water absorbing media. A second end cap closes the outer end of the core and water absorbing media. The second end cap has a central opening there through. A valve cylinder cup is secured to the second end cap and extends within the central opening in the core. The valve cylinder cup has at least one opening in the side wall thereof. A valve piston is slidably disposed and guided in the valve cylinder cup and movable to open and close the openings in the sidewall of the valve cylinder cup.

Abstract: A system for controlling fluid flow to an approximate constant rate is disclosed. The system includes a housing, a flow control element, a cutout formed in the flow control element, a valve element, and a spring. The housing has an inlet opening and an outlet opening. The ends are arranged and configured to receive piping. The flow control element is operatively positioned within the housing with the flow control element having an upstream end and a downstream end with a cutout formed therein. The fluid flows in the inlet and through the cutout into a larger chamber within the housing before exiting the outlet end of the housing in normal flow. A valve element is disposed within the housing adjacent and upstream of the flow control element. The valve element is positioned within the housing by a spring means which urges the valve element toward the outlet.

Abstract: The fluid handling devices are capable of accurately handling substantially continuous fluid flow rates as low as about 0.01 cc/day. The devices are so miniaturized, corrosion-resistant and non-toxic that they are suitable for being implanted in the human body; and are capable of being mass produced at costs so low, by using micromachining techniques, such as etching, that they may be considered to be disposable. The devices are either passive devices which consume no electrical energy at all, or are active devices which consume very small amounts of electrical energy. The devices are reliable because they may have as few as only two parts, only one which is a moving part; and because they may handle fluids at very low pressures. The fluid handling devices include active piezoelectrically driven membrane pumps; and passive fluid flow regulators, on-off valves, flow switches and filters.

Abstract: A water-operated hydraulic control valve is disclosed, having a throttling device which comprises a throttling element (20) which is in the form of a piston which cooperates with a substantially hollow-cylindrical counter-element (8).In order also to be able to operate such a control valve with water, that is, a non-lubricating fluid of low boiling point, the throttling element (20) projects with one end (29) into the counter-element (8). Distributed in the circumferential direction, several apertures (30) are provided in the throttling element (20) or in the counter-element (8), forming a flow path through the overlap region between throttling element (20) and counter-element (8), and distributed in the circumferential direction there is provided an arrangement of pressure pockets (33), which arrangement is in fluid connection with the apertures (30) and is arranged at least partially in the overlap region.

Abstract: A fluid flow device has a body which includes an inlet and an outlet with a valve seat therebetween. A valve stem having a valve member thereon is mounted in the body, and the valve member is operably connected to a diaphragm which separates a region within the body into a pair of separate pressure chambers. A fluid passage is formed in the body communicating one pressure chamber with upstream pressure in the inlet, while the other pressure chamber communicates with downstream pressure in the outlet. A pressure differential between the chambers will normally hold the valve member in an open position against the action of a biasing means, until the pressure differential reaches a predetermined amount, whereby the valve member is slowly closed until fluid flow through the device is stopped.

Abstract: A valve assembly for controlling fluid flow to an actuator, including first and second throttles for controlling partial flows therethrough, which together form a full flow to the actuator and which function indepedently from each other and are formed each by a variable metering orifice, and a flow control valve for controlling fluid flow through the first throttle and including a valve spool and a spring for biasing the valve spool to a position of a maximum predetermined fluid flow through the first throttle.

Abstract: A regulator for maintaining a constant partial vacuum in a region, such as in a piece of process equipment or a fume hood. The regulator includes a path, through which fluid passes from the region to the vacuum source, and a movably mounted piston having a frontal face, which is exposed to fluid in the path, and a distal face, which is exposed to a reference pressure, such as the pressure of the environment in which the equipment is located. The piston is disposed in the path so that the piston may constrict the path at a constriction point. Fluid in the path upstream of the constriction point exerts a pressure on the frontal face of the piston that tends widen the path at the constriction point. The piston is mounted so that the weight of the piston exerts a force on the piston in a direction that tends to widen the path at the constriction point. A force is exerted on the piston, preferably by a spring under compression, in a direction that tends to narrow the path at the constriction point.

Abstract: A valve assembly for controlling volume flow from a discharge device to an actuator and including a discharge throttle, and a flow control valve for controlling flow through the throttle and having a piston, and end portion of which overlaps a channel for returning excess fluid to a suction side of the discharge device and has an end region forming a seated valve preventing leakage past the end region, when the end region completely overlaps the return channel.

Abstract: A pressure regulator for an industrial process system is connected between the industrial process equipment and pollution control equipment and exhibits a pressure inversely related to pressure changes in the pollution control equipment so as to maintain the exit pressure at the process equipment constant.

Abstract: A pneumatic fluid flow limiting device which is pressure compensated and resets automatically when the pneumatic fluid driven device is shut off. Pressure compensation is accomplished by a vented differential diameter chamber and reset is accomplished by a bypass orifice in a spool valve which further may be variable in flow to accommodate different flow requirements for tool operation.