Abstract: The disclosure relates to a valve comprising a body defining at least an admission duct and an outlet duct for a fluid and receiving a valve member that is movable by means of an actuator member fastened to the body to move between a closed position closing the outlet duct and an open position leaving it open, the valve member having a central portion secured to a central portion of a substantially plane diaphragm that has a peripheral portion associated in leaktight manner with a support element secured to the body in such a manner as to co-operate with the support element to define a chamber, the valve member and the diaphragm being pierced by an opening providing permanent communication between the chamber and the outlet duct, the diaphragm being elastically deformable and being dimensioned to urge the valve member into its closed position.

Abstract: A flush valve diaphragm of a flush valve includes a body having a segmented insert within a flexible body portion and a central passageway. The body further includes a peripheral sealing portion with the flexible body portion within the peripheral sealing portion. The peripheral sealing portion can include an integral filter, an exit chamber and a bypass arrangement, such that water flowing through the filter flows through the bypass arrangement. The integral filter version will retard clogging of the bypass arrangement. The segmented insert includes a plurality of trapezoidal members with outward protrusions. The plurality of trapezoidal members are connected to each other on their outermost edge by a runner.

Abstract: An object is to provide a flow control valve that is capable of reducing or eliminating backlash generated between a male threaded portion and a female threaded portion engaged with the male threaded portion and preventing or eliminating hysteresis in the flow level. The flow control valve includes a body having a fluid inlet and a fluid outlet, a cover attachable to the body, a motor disposed in a space defined by the body and the cover, a valving element connected to a rotary shaft of the motor with a screw member, and an urging member that urges the valving element toward the motor side or toward the side opposite to the motor.

Abstract: Membrane valves and latching valve structures for microfluidic devices are provided. A demultiplexer can be used to address the latching valve structures. The membrane valves and latching valve structures may be used to form pneumatic logic circuits, including processors.

Abstract: Pressure activated valves for catheters with improved tolerance of high pressure and high flow conditions are described. Embodiments of the valve comprise a flexible membrane with one or more linear slits therethrough, and means for applying tension to the flexible membrane in-line with the linear slits. The application of tension may optionally be facilitated by structural features of both the flexible membrane and the valve housing.

Abstract: A membrane valve comprising a first and a second valve housing part and a membrane clamped between the valve housing parts comprises a peripherally surrounding bead on the membrane and a thin, axially movable membrane portion adjacent thereto. The bead is supported by the two valve housing parts and is provided with an undercut at a radial inner side. Further, a membrane for installation in a membrane valve is provided.

Abstract: A diaphragm control valve has a universal diaphragm mounting location, the diaphragm control valve includes a bonnet, a valve body, a diaphragm, and a clamping washer. The bonnet includes a first clamping surface that transitions into a first annular retention surface formed by a skirt, and the valve body includes a second clamping surface that transitions into a second annular retention surface formed by an upturned annular lip.

Abstract: A cover-equipped manual valve having a ratchet mechanism for preventing rotation of a knob, comprising: a rod formed with an external thread portion on an outer periphery thereof, the rod being unconnected to the knob and held against rotation; a sliding nut of a cylindrical shape, the sliding nut being rotatably held by a body and internally formed with an internal thread portion threadedly engaged with the external thread portion of the rod; an engagement member fixed to the knob, the engagement member being elastically deformable to be engaged with the sliding nut and to be disengaged from the sliding nut when larger torque than a predetermined value is applied to the engagement member; and a knob cover of a hollow shape for covering the knob.

Abstract: A cam control valve includes a valve casing having a fluid passage and valve seat, a valve disc seated on the valve seat to open and close the fluid passage, a valve stem holding down the valve disc so it contacts the valve seat, a cam acting on the valve stem to hold it down, a motor rotating the cam, a motor holder holding the motor, a supporting frame fixed to the valve casing and supporting the motor holder so it moves vertically, an elastic member biasing the motor holder towards spacing from an upper side portion of the supporting frame, and height adjustable screws suspending the motor holder from the supporting frame, and adjusting a height of the motor holder with respect to the supporting frame, wherein the height adjustable screws are slidably inserted into the upper side portion of the supporting frame and screwed into the motor holder.

Abstract: A direct touch type metal diaphragm valve, wherein durability of the valve, that is to say, the ensured number of continuous open/close operations of the valve, is substantially increased under conditions that an appropriate flow rate coefficient Cv is maintained, and changes of the afore-mentioned Cv value over time are mitigated by means of restricting the deformation of the valve seat over time. The afore-mentioned metal diaphragm is formed in a round, reverse-dish shape by laminating a plural number of thin stainless steel plates and a thin Nickel.Cobalt alloy plate, and its center part is bulged upward, and the maximum valve stroke of the valve is regulated to be 55% to 70% of the distance of the maximum bulge height ?h of the afore-mentioned metal diaphragm.

Abstract: The invention relates to a microfabricated device for the rapid detection of DNA, proteins or other molecules associated with a particular disease. The devices and methods of the invention can be used for the simultaneous diagnosis of multiple diseases by detecting molecules (e.g. amounts of molecules), such as polynucleotides (e.g., DNA) or proteins (e.g., antibodies), by measuring the signal of a detectable reporter associated with hybridized polynucleotides or antigen/antibody complex. In the microfabricated device according to the invention, detection of the presence of molecules (i.e. Polynucleotides, proteins, or antigen/antibody complexes) are correlated to a hybridization signal from an optically-detectable (e.g. fluorescent) reporter associated with the bound molecules. These hybridization signals can be detected by any suitable means, for example optical, and can be stored for example in a computer as a representation of the presence of a particular gene.

Abstract: A high pressure diaphragm gas valve comprises a removable seat assembly (32), including a mounting ring (34) and a synthetic seat ring (36), which is fitted in a central seat hole of a mounting ring (34). A nozzle (60) penetrates in a sealed way into a central through hole (38) of the synthetic seat ring (36). A first gas port (28) is arranged in a front face (62) of the nozzle (60). A second gas port is formed by a gas collecting ring channel (30) incorporated into the valve body (12), wherein it surrounds a nozzle shoulder surface (64) of the nozzle (60) and is itself surrounded by an outer shoulder surface (102) of the valve body (12). The mounting ring (34) is supported with an inner ring flange (82) on the nozzle shoulder surface (64) and with an outer ring flange (84) on the outer shoulder surface (102), so that peripheral gas passages (86) open into the ring channel (30).

Abstract: A multistage, pilot-operated pressure regulator for pressure adjustment and/or back pressure relief and/or differential pressure or flow control applications comprises a diaphragm and a plurality of plates, including a throttle plate and at least one flow control plate. In at least one embodiment, the throttle plate includes a sloped upper surface for contacting the diaphragm, and a plurality of apertures residing within a plurality of concentric rows. In addition, in at least one embodiment, at least one flow control plate is positioned downstream of the throttle plate, the at least one flow control plate including a plurality of apertures residing within a plurality of concentric rows. A method of controlling the flow of fluid in a conduit is also provided.

Abstract: A diaphragm valve for use in an irrigation system is disclosed that is adapted to reduce the water hammer effect, reduce debris in a flow path through a valve seat, improve bleed operation and/or reduce manufacturing and materials costs.

Abstract: A fluid control valve includes a resin valve body formed with first and second passages, a resin valve upper part connected to an upper surface of the valve body, and a resin diaphragm valve element held between the valve body and the valve upper part.

Abstract: The present invention relates to a duct connector for working fluid, that is durable and corrosion resistant, and a valve with the duct connector. The duct connector has a head portion with an internal fitting portion that fluidly communicates with the inside of a cylinder housing of the valve. It is affixed to the housing in such a manner that the head portion protrudes from the outer surface of the housing with the fitting portion being positioned outside the outer surface of the housing. Duct connectors may be formed by insert molding using a resin with a tensile elongation ratio of 50%-400% and tensile strength of 50 Mpa -200 MPa.

Abstract: A safety device for a gas distribution system includes a valve body, an upper casing attached to the valve body, the upper casing housing two springs. The two springs are co-axially located and separated by a casting tube. Further, the two springs are attached to a movable diaphragm that is exposed to gas system pressure. A snap ring flange is also attached to the valve body, the snap ring flange being used to secure the safety device to a main regulator in the gas distribution system. The valve body also includes a cam mounted within the valve body. A limit switch is directly connected to the cam such that the limit switch moves directly in response to movement of the diaphragm. Additionally, a reset pin extends from the valve body and interacts with the cam such that the cam may be reset from a closed position to an open position by moving the reset pin.

Abstract: The invention relates to a membrane valve, in particular for inhalation devices, comprising a planar membrane made of permanently flexible material, a frame, which has an air opening that is somewhat smaller than the membrane, at least one web, which connects the frame to a retainer that is arranged approximately at the center of the air opening, and a pin, the shaft of which extends through a fastening opening approximately at the center of the membrane and is located in a retaining opening in the retainer, wherein the membrane lies on the frame in the rest state and wherein the pin is spread to form a head, the distance of which to the membrane is small in comparison to the thickness of the membrane or which head lies on the membrane, and the diameter of the shaft near the head is greater than the diameter of the fastening opening,; and the diameter of the shaft at the free end of the shaft is approximately equal to the diameter of the fastening opening.

Abstract: A vacuum valve installed on an opening of a sealed container includes an air-resistance membrane, a valve and at least one airflow passage. The valve is latched on the opening. The airflow passage runs through the valve and communicates with the sealed container. The air-resistance membrane is mounted onto the valve and has an annular flange to surround and seal the airflow passage. The protrusive annular flange is deformable to form an airtight structure to maintain a vacuum condition in the sealed container for a prolonged duration to meet use requirements.

Abstract: A metering assembly includes a fluidic chip and metering chambers. Selectable outlet valves communicate with each metering chamber to provide a discrete dispensed volume. The valves may be commonly controlled and may be formed as multi-level valves. The valves may be grouped into common substrate valve clusters. Purge channels communicate with the metering chambers and controlled purge valves allow reverse flow wash fluid to wash the metering chamber. Pressure ports are employed to actuate the valves. A method of dispensing a fluid from the fluidic chip includes a) to selectively filling (or filling) the metering chambers with a selected fluid; and b) outputting (or selectively outputting) the fluid to output locations. The total output volume of fluid dispensed from each metering chamber may be accumulated. The process may be repeated until the accumulated volume equals the desired volume and may be repeated for another fluid from a plurality of different fluids.

Abstract: A water drain valve for an electromechanical motor vehicle power steering may include a base and a diaphragm which is configured as a movable valve element and is arranged such that it can move relative to the base between a closed position and an open position. In the closed position, the diaphragm rests against the base along an annular ring. The base may have a passage which extends from a free opening to a floor, with the diaphragm being attached centrally to the floor, the floor having at least one opening which forms a connection from the passage to the diaphragm, and the floor having at least one groove which is open towards the diaphragm and extends from the at least one opening as far as the annular ring.

Abstract: A diaphragm valve is used to perform opening/closing operations to switch between a state where two flow paths 14a and 15a communicate with each other and a state where the flow paths 14a and 14b are blocked from communicating with each other. A diaphragm unit 31 which is disposed in a valve housing 13 has a hollow valve body 32 capable of being reciprocated in the axial direction, the diaphragm unit 31 is formed with a communication flow path 32a through which two flow paths 14a and 14b are communicated with each other. A first diaphragm 34 is provided to one end portion of a hollow valve body 32, and a second diaphragm 36 is provided to the other end of the hollow valve body 32, when the hollow valve body 32 is moved in its axial direction and abuts on a valve seat portion 42, the communication flow path 32a is closed.

Abstract: A bathroom flusher includes a body having an inlet in communication with a supply line and an outlet in communication with a flush conduit, a valve assembly in the body positioned to close water flow between the inlet and the outlet upon sealing action of a moving member at a valve seat thereby controlling flow from the inlet to the outlet, and an actuator for actuating operation of the moving member. The bathroom flusher includes one of several novel sensors and is controlled by one of several novel controllers, as described. The controller may execute a novel control algorithm.

Abstract: A valve for a fluid passage in a vehicle fuel cell system. A housing includes an inflow passage connected to an upstream side of the fluid passage and an outflow passage connected to a downstream side of the fluid passage. A valve body is disposed in the housing and includes an intermediate fluid passage configured to provide fluid communication between the inflow passage and the outflow passage. A heating element is configured to apply heat directly to the valve body.

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

Abstract: Diaphragm valve having a valve body with an inlet and an outlet, a sealing membrane, and a connecting piece connecting the sealing membrane to a pressure piece of a drive. The valve body, the sealing membrane and the connecting piece are rigidly connected together to form an interchangeable, sealed valve body unit that can be connected to the drive. The connecting piece is molded on the sealing membrane, and the valve body and the sealing membrane are welded ultrasonically to one another.

Abstract: A pneumatic valve actuator for moving the valve stem of a control valve comprises an upper casing and a lower casing each having flanges, a diaphragm plate operatively coupled to the valve stem, a spring arranged to bias the diaphragm plate in a first direction, a diaphragm movable in conjunction movement of the diaphragm plate, an air inlet defined in the casing and arranged for attachment to an air supply source to bias the diaphragm plate in a second direction, and a ring disposed between the upper flange and the lower flange and positioned to engage the outer portion of the diaphragm. The ring includes a protrusion positioned to engage a surface of the outer portion of the diaphragm.

Abstract: A rocker type diaphragm valve is disclosed. The diaphragm (428) in the diaphragm valve is asymmetric and the stroke of the diaphragm is offset from the center of the diaphragm. The two sealing surfaces (318, 320) that the diaphragm acts against form two planes that make an angle with respect to ones another. The diaphragm (428) may be fabricated in only one piece. The diaphragm (428) may also be made from a resilient material and shaped in such a way as to create a spring force holding the diaphragm into a default position in the valve.

Abstract: A diaphragm sealed, pressure balanced valve assembly includes a valve body and a cartridge connected to the valve body. The cartridge includes a cartridge loading end having a retaining member engaged to the cartridge loading end. A valve member slides coaxial to a longitudinal axis of the valve body. A resilient material first diaphragm is connected to and extends diametrically outward from the valve member having a diaphragm body clasped between the retaining member and the cartridge loading end, creating a first diaphragm fluid pressure boundary. A resilient material second diaphragm is connected to and extends diametrically outward from the valve member at an opposite end of the valve member with respect to the first diaphragm and has a diaphragm body clasped between first and second adjustable retention members, creating a second diaphragm fluid pressure boundary.

Abstract: A volume booster for a fluid flow control device comprises a supply path for supplying a fluid boost to facilitate actuation of an actuator in a first direction, and an exhaust path for enabling controlled exhaust to facilitate actuation of the actuator in a second direction. The supply path defines a supply resistance that is set by the geometry of a supply trim component. The exhaust path includes an exhaust resistance that is set by the geometry of an exhaust trim component. The supply and exhaust trim components are independently removable and replaceable with replacement components to customize the exhaust and supply resistances, and therefore, the exhaust and supply capacities for specific applications.

Abstract: Novel features enhancing the operation of a diaphragm valve include a specialized diaphragm profile for enhanced securement of the diaphragm in the valve body, and a quick-connect feature joining the diaphragm to its actuator, in which the forward end of the actuator contains a sloping surface, an expanded tip, and a shoulder, while the diaphragm contains a truncated bore with a complementary profile. The valve can be modular in construction to permit mounting of the valve to an instrument panel in close proximity to other valves or components to provide the ability to select among interconnected fluid flow paths.

Abstract: Diaphragm valve (1) comprising a housing upper part (2), which receives an actuating device (4) for actuating the valve (1), and a housing lower part (3), which has a receiving region (9) for receiving a diaphragm (11), wherein in the housing lower part (3) below the diaphragm (11) a central region forming a flow channel (17) is designed, wherein the cross-sectional surface of the flow channel (17) in the central region (51) of the housing lower part (3) is constant when the valve (1) is in the open state.

Abstract: A valve for a pressure vessel system includes a housing including a cavity and a hollow fluid flow portion. A membrane actuator is disposed in the cavity of the housing. A piston is disposed in the cavity and in the hollow fluid flow portion of the housing. A spring is disposed in the hollow fluid flow portion of the housing. The spring biases a piston head toward a fluid flow port formed in the hollow fluid flow portion. The piston head seals the fluid flow port when the biasing of the piston head by the spring is not countered by an opposite deflection of the membrane actuator.

Abstract: The invention relates to a microfabricated device for the rapid detection of DNA, proteins or other molecules associated with a particular disease. The devices and methods of the invention can be used for the simultaneous diagnosis of multiple diseases by detecting molecules (e.g. amounts of molecules), such as polynucleotides (e.g., DNA) or proteins (e.g., antibodies), by measuring the signal of a detectable reporter associated with hybridized polynucleotides or antigen/antibody complex. In the microfabricated device according to the invention, detection of the presence of molecules (i.e., polynucleotides, proteins, or antigen/antibody complexes) are correlated to a hybridization signal from an optically-detectable (e.g. fluorescent) reporter associated with the bound molecules. These hybridization signals can be detected by any suitable means, for example optical, and can be stored for example in a computer as a representation of the presence of a particular gene.

Abstract: Communication between microchannels of a microfluidic circuit is controlled through a combination between a membrane and a pin-actuated valve arrangement. The deformable membrane contributes to the formation of the surface of the microchannels. Alternatively, or in addition, the valve arrangement is operated through combination of the membrane with a control fluid. Systems, devices and methods based on such communication are shown. Also shown are methods to manufacture a system having a fluidic circuit and a control arrangement.

Abstract: An aseptic diaphragm valve in which a valve seat (37) is formed by a groove including a concave surface of engagement that positioned along an outer diameter of an upper end of an inlet tube (32), and a resilient valve member portion (41) that is annular in extent with a convex surface that moves into the groove to contact the concave surface (37) around the outer diameter of the inlet tube (32) to close the valve. The valve member portion (41) has at least a coating of polytetrafluoroethylene (47) or equivalent material.

Abstract: The invention describes a leak proof shaft seal for valves and other pressurized vessels, wherein the shaft seal can deform elastically by either stretching or twisting without loosing its ability to seal all, or a portion, of said shaft from harmful fluids. Furthermore, the elastic shaft seal is immune to static pressures, since it closely surrounds a shaft and thus is protected from collapse.

Abstract: A diaphragm-sealed valve having communication mechanisms operatively connecting neighboring pairs of grooves is provided. Each communication mechanism has a communication port opening in an interface of a valve cap, between the neighboring grooves. The communication mechanism also has a communication conduit extending within the valve cap and connecting the communication port and one of the neighboring grooves. It also has a recess within a valve body aligned with the communication port and with the other one of the neighboring grooves, a flexible sealing surface of the diaphragm being seated within the recess and resiliently biased away from the interface of the valve cap. A plunger assembly is also provided, including plungers movable to push flexible sealing surface towards the communication port.

Abstract: A flow control device is provided comprising: a housing (19) including a first chamber (21) communicated with an inlet port (11) and a second chamber (22) communicated with an outlet port (12); a cylindrical portion (25), which extends in the second chamber, for communicating the first chamber with the second chamber; a valve seat (61) provided at a forward end portion (25a) of the cylindrical portion; and a valve body (32) for opening and closing the valve seat, wherein at least one of the valve seat and the valve body is made of a material, the heat deformation of which is smaller than that of material composing the cylindrical portion. Due to the foregoing, it is possible to stably adjust the flow rate of a fluid of a high temperature and pressure. A pressure chamber (29), which is communicated with the second chamber and provided with a pressure port (18), may be arranged in the housing.

Abstract: The present invention relates to a pulse valve (10) with a closing body (18) that cooperates with a valve seat (22) and, in a first switching position, establishes a flow connection between a supply channel (12) and a discharge channel (14) and, in a second switching position, blocks the flow connection. The closing body (18) periodically alternates between the two switching positions during the actuation of the pulse valve (10), its movement being hydraulically damped by a throttle point (70). It is provided that the hydraulic damping occurs only in a subrange of motion (62).

Abstract: A reed valve is adapted to be fixed to a fixing member. The reed valve includes a valve plate and a resiliently deformable reed. The valve plate is fixed to the fixing member and includes a frame part and a supporting column. The frame part has an opening inward of the frame part. The opening passes through the frame part in a thickness direction of the valve plate. The supporting column is disposed across an inside of the opening. The reed is configured to open or close the opening. The frame part includes a frame seating surface with which the reed is engaged. The supporting column includes a column seating surface with which the reed is engaged. The column seating surface is recessed relative to the frame seating surface in the thickness direction.

Abstract: A microfluidic diaphragm valve. The valve comprises: an inlet port; an outlet port; a weir positioned between the inlet and outlet ports, the weir having a sealing surface; a diaphragm membrane for sealing engagement with the sealing surface; and a thermal bend actuator for moving the diaphragm membrane between a closed position in which the membrane is sealingly engaged with the sealing surface and an open position in which the membrane is disengaged from said sealing surface.

Abstract: The invention relates to a drainage assembly of the type having an upward opening for the draining opening of a new or existing chemical reactor, particularly of the enameled type, characterized in that the outer outlet opening (6) for the drainage is provided in the lower portion thereof with a removable seat part in the form of a planar annual seal (11) having an upper portion with at least one recess (21) used as a seat for the under-face of the head (10) of the valve and as a full flow ramp. The invention is particularly intended for the manufacturers and users of chemical reactors, in particular of the enameled type.

Abstract: For providing a fluid control valve capable of preventing looseness of a screw part between a valve main body and a valve upper body, the fluid control valve comprises a resin valve main body wherein a valve seat comes into or out of contact with a diaphragm, and a resin valve upper body engaged with the valve main body. The fluid control valve comprises a holding member to keep the valve main body and the valve upper body threadedly screwed together.

Abstract: The present application is directed to a gas-generating apparatus and various pressure regulators or pressure-regulating valves. Hydrogen is generated within the gas-generating apparatus and is transported to a fuel cell. The transportation of a first fuel component to a second fuel component to generate of hydrogen occurs automatically depending on the pressure of a reaction chamber within the gas-generating apparatus. The pressure regulators and flow orifices are provided to regulate the hydrogen pressure and to minimize the fluctuation in pressure of the hydrogen received by the fuel cell. Connecting valves to connect the gas-generating apparatus to the fuel cell are also provided.

Abstract: A diaphragm sealed flow cavity comprises a first body comprising a support surface, a diaphragm comprising an outer portion that is joined by a weld to the first body, a clamped portion, and an inner portion that is movable along an axis, with the clamped portion of the diaphragm being compressed between the bearing surface and the support surface. The diaphragm sealed flow cavity may include a cylindrical body having a crimped portion for joining the cylindrical body to the first body. The diaphragm sealed flow cavity may also include a member that applies a live load to the clamped portion of the diaphragm. In the exemplary embodiments, the diaphragm sealed flow cavity may be realized as part of a diaphragm flow control valve having a valve body, diaphragm and a housing.

Abstract: A widely used marking pen for dispensing viscous substances comprises: a casing with a dispensing tip, a ball being spring biased to selectively reveal a dispensing tip orifice that permits pressurized flow therefrom, a flexible bulb member with orifice therein permitting repeatable finger actuated pressurization of the casing interior, and a valve positioned between the liquid/semi-paste substance and the flexible bulb member. The valve maintains, on the downstream side, air under pressure to ensure good flow of the substance. The invention herein offers improvements over such valves by reducing the number of parts that are commonly used, thereby reducing complexity of its assembly, while offering improved results in terms of the longevity in maintaining pressure within the casing. The valve may comprise a stand-alone diaphragm with a specially contoured and resilient diaphragm wall having a self-sealing slit therein that independently permits pressurized fluid flow in only the desired direction.

Abstract: The present invention concerns a drain valve assembly with a pop-up drain stopper for a drain opening. The drain valve assembly has an improved sealing mechanism whereby the drain valve assembly may be easily installed and, in addition, the interface between the drain valve assembly and the drain opening may be easily cleaned.

Abstract: The invention relates to a valve, in particular for a component in microfluid technology, comprising valve bodies (1, 2) which have surfaces (6, 7) intended for contact with each other and which can be moved relative to each other by displacing the contact surfaces (6, 7), wherein channels (4, 5) for the inflow and outflow of a fluid open into one (6) of the contact surfaces (6, 7) and a depression (9) for forming a connection between the channels (4, 5) is provided in the other contact surface (7). According to the invention, a flexible separating film (10), which can be stretched into the depression (9) to form the connection, is arranged between the contact surface (6, 7).

Abstract: A MEMS integrated circuit comprising one or more microfluidic diaphragm valves and control circuitry for the valves. Each valve comprises: an inlet port; an outlet port; a weir positioned between the inlet and outlet ports, the weir having a sealing surface; a diaphragm membrane for sealing engagement with the sealing surface; and a thermal bend actuator for moving the diaphragm membrane between a closed position in which the membrane is sealingly engaged with the sealing surface and an open position in which the membrane is disengaged from the sealing surface. The control circuitry is configured to control actuation of the actuator so as to control opening and closing of the valve.