Abstract: A fluidic device controls fluid flow in channel from a source to a drain. In some embodiments, the fluidic devices comprise a gate, a channel, and an obstruction. The gate comprises at least one chamber whose volume increases with fluid pressure. A high-pressure state of the gate corresponds to a first chamber size and a low-pressure state of the gate corresponds to a second chamber size that is smaller than the first chamber size. The obstruction controls a rate of fluid flow within the channel based on the fluid pressure in the gate. The obstruction induces at most a first flow rate of fluid in the channel in accordance with the low-pressure state of the gate, and at least a second flow rate of the fluid in the channel in accordance with the high-pressure state of the gate.

Abstract: An inlet check valve for controlling fluid from a supply into a variable cam timing phaser includes a double flapper check valve assembly with an open position and a closed position, which includes a housing having a body, at least one stopper, a flapper valve comprising at least two flexible flaps received within the housing and aligned with the stopper(s), and a valve seat received within the housing, the valve seat defining openings aligned with the at least two flexible flaps, axially opposite the two stoppers.

Abstract: An apparatus is described for controlling a flow of a fluid therethrough while the apparatus is connected to a source of control fluid. The apparatus includes an input, a valve seat, a diaphragm, an output, and a diaphragm control space. The diaphragm control space is partially defined by the diaphragm, and includes a control fluid inlet and a control fluid outlet. The apparatus is operative to independently control a flow of control fluid into the diaphragm control space through the control fluid inlet and a flow of control fluid out of the diaphragm control space through the control fluid outlet. A deflection of the diaphragm in relation to the valve seat is responsive to a pressure of the control fluid in the diaphragm control space. The deflection of the diaphragm in relation to the valve seat is operative to control a fluidic flow resistance between the input and the output.

Abstract: A vapor compression refrigeration cycle system includes a compressor and an electronic expansion valve connected between first and second refrigerant ports of a compressor. An expansion valve controller is configured to control a flow of refrigerant through the expansion valve in response to a superheat temperature of the refrigerant. The controller is configured to execute a first control algorithm until a local maximum of the superheat temperature occurs, and then to execute a second control algorithm.

Abstract: Gas turbine, software and method for controlling an operating point of the gas turbine that includes a compressor, a combustor and at least a turbine is provided. The method includes determining a turbine exhaust pressure at an exhaust of the turbine; measuring a compressor pressure discharge at the compressor; determining a turbine pressure ratio based on the turbine exhaust pressure and the compressor pressure discharge; calculating an exhaust temperature at the exhaust of the turbine as a function of the turbine pressure ratio; identifying a reference exhaust temperature curve in a plane defined by the exhaust temperature and the turbine pressure ratio; and controlling the gas turbine to maintain the operating point on the reference exhaust temperature curve.

Abstract: Apparatus to control a fluid flow are disclosed. An example fluid flow control apparatus described herein includes a signal stage comprising a signal stage relay having a supply plug being operatively connected to a valve seat at a first end and an exhaust seat at a second end and a seal operatively coupled to the supply plug such that the seal provides a feedback area to apply a fluid pressure feedback force to the exhaust seat.

Abstract: Microfluidic shunt valves are disclosed having a deflectable element capable of being held in a closed position to occlude the passage of fluid between an inlet and outlet and, when not held in the closed position, the deflectable element is adapted to oscillate in response to fluid pressure pulses and thereby facilitate fluid passage through the valve. Controls for activating the deflectable element to permit fluid passage are also included.

Abstract: A deadweight pressure standard provides improved measurement accuracy and repeatability. The standard includes a flow regulator having a first valve controlled by a first pair of non-hysteresis sylphons, and a supply regulator having a second valve controlled by a second pair of non-hysteresis sylphons. The first and second valves achieve an equilibrium state between the supply regulator and the flow regulator. The second valve regulates pressure generated by an applied pressure supply. A mass-to-pressure transducer transforms an applied gravitational force into a reference pressure regulated by the first valve. The center of pressure force on the first pair of non-hysteresis sylphons, and the center of pressure force on the first valve, are exerted along a first reference axis. The center of pressure force on the second pair of non-hysteresis sylphons, and the center of pressure force on the second valve, are exerted along a second reference axis.

Abstract: A system tot the pulsation-free delivery of liquids, which system may be used for high-purity, liquid chemicals in the semiconductor industry.

Abstract: A strategy for controlling an air side economizer of an HVAC system uses a model of the airflow through the system to estimate the load in two modes when minimum and maximum amounts of outdoor air are being introduced into the building. Transitions between minimum outdoor air and maximum outdoor air usage occur based on those estimated loads, which in a preferred embodiment are cooling loads. The second embodiment of this economizer control strategy uses the model and a one-dimensional optimization routine to determine the fraction of outdoor air that minimizes the load on the HVAC system.

Abstract: A valve return passage for quickly returning a valve to a closed position, includes return passages for communicating discharge pressurized fluid to a rear surface of a floating valve. The use of the return passages ensures that pressurized gas is communicated quickly to close the valve at shut down. This reduces the noise of operation of the compressor.

Abstract: When a steplike reference signal is supplied while a switch is open, an offset signal for compensating for the dead time of a pneumatic device is generated by an offset generator and supplied as a manipulated variable for the pneumatic device. When a feedback increases in level and a speed higher than a reference speed is detected by a speed detector, the switch is closed by a switching signal, switching from a PD control mode to a PID control mode. The pneumatic device thus controlled has a reduced response time and can made a quick response.

Abstract: An installation for lubricating, cleaning and/or disinfecting conveyor belts for containers, more particularly for foods, such as bottles, glasses, cans, bags and the like, comprising a central metering station connectable to a water pipe used to dilute a concentrated lubricant, cleaner or disinfectant, and several distributing pipes connected to the metering station lead to the points of use. At each point of use there is a mixing valve (13-19) connectable to distribution line (52) and the water pipe (23) and individually adjustable for each point of use and a pressure reducer (50, 51) fitted upstream of each mixing valve. Varying concentration can be provided for each point of use (31-37) with little technical complexity. In another embodiment, the invention is the process carried out by the installation.

Abstract: An electro-pneumatic converter device with modular components and with supporting housing structure enabling the device to be readily convertible from a current to pressure positioner to a current to pressure transducer. A valve positioner with an enclosure having a housing, a modular base, and a separable field terminal box. A self contained cover mounted to the enclosure with no additional mounting components. A plastic pneumatic relay ultrasonically welded together to eliminate metal mounting parts and lower assembly time. Open channels in a housing surface cooperating with a gasket to provide fluid passageways between the housing and the modular base. Pressure gauges are removably mounted on a modular unit for location completely within the housing. A floating interconnect terminal board permits self-aligning of mating terminals as the modular unit is inserted into the housing.

Abstract: A transducer having an explosion-proof housing with a divider forming two compartments, and the divider having formed therein a well. A magnet and flapper arm arrangement is suspended within the well. A coil winding is fixed in the other compartment around the well so that a magnetic field generated thereby influences the pivotal position of the magnet. Set screws adjustable in the bottom of the well are effective to preset a rest position of the magnet.

Abstract: A transducer having an explosion-proof housing with a divider forming two compartments, and the divider having formed therein a well. A magnet and flapper arm arrangement is suspended within the well. A coil winding is fixed in the other compartment around the well so that a magnetic field generated thereby influences the pivotal position of the magnet. Set screws adjustable in the bottom of the well are effective to preset a rest position of the magnet.

Abstract: This invention relates to a pneumatic control device having an operating mode selecting means for operating in either the manual or automatic modes. Pneumatic pressure is regulated in the manual mode by a hand operated leakport, and in the automatic mode by a voice coil or other pressure regulating device. The pneumatic input supply, manual pressure regulating means and voice coil all communicate at a common surface. The mode selecting means slides across this common surface to connect together the pneumatic input supply with one of the selected pressure regulating means.

Abstract: An electropneumatic converter is provided with a voice coil having a vane directly connected to the coil. The vane and coil assembly is attached to a spring and resiliently supported by the spring for movement relative a nozzle outlet in response to dc input signals applied to the coil.

Abstract: The incremental interface system of the present invention includes a pneumatic input means for providing a first pressure to be regulated. A pressure repeater means includes a volume relay having a first chamber coupled to the intermediate bus of the input means and a second chamber coupled to a pneumatic transducer to be controlled, the first chamber and the second chamber being in fluid flow isolation one from the other. The pressure repeater means provides a second pressure at its second chamber which has a predetermined relationship to the first pressure. A reservoir means is coupled to the intermediate bus between the input means and the repeater means for limiting the rate of change of the first pressure. The input means, repeater means and reservoir means cooperate to define a substantially constant volume of fluid.

Abstract: The interface apparatus of the present invention includes a pneumatic flow control means for controlling the number of moles of a gas confined within a substantially constant volume of gas at a first pressure. A volume relay has a first chamber coupled to the control means by a pneumatic bus and a second chamber for coupling to a pneumatic transducer to be positionably controlled, the first chamber and the second chamber being in fluid flow isolation one from the other. The volume relay provides a second pressure at its second chamber which has a predetermined relationship to the first pressure. A substantially constant, confined volume is coupled to the flow control means and to the relay and the flow control means includes means for adjusting the rate of flow of gas from the substantially constant volume to a region of ambient pressure.

Abstract: A modular transmitter has an outer housing with a wall forming an interior cavity in which a control module is inserted. The wall has one or more ports therein that are connected to pressure conduits. When the control module is fully seated, the ports align with internal passageways in the control module that lead to control components in the control module. The control module further has an electrical circuit supported on an end thereof that is toward the inner end of the cavity when the control module is inserted and the circuit has components that removably mate with further elements mounted on the end wall of the cavity. These connections may include electrical contacts, and also rotationally adjustable components that have set points and which are coupled to set point adjustment and control shafts that are accessible from the opposite side of the end wall from the cavity.

Abstract: A pressure regulator (75) of a flow control system includes a pair of orifices (140 and 145), the effective areas of which are controlled by a pair of flexible closures (150 and 155) unidirectionally stiffened against fluid flow thereagainst. The closures remain flexible in an opposite direction so that when one of the closures is fouled with contaminants, it does not impede the operation of the remaining closure.

Abstract: A pneumatic control system, control unit and method of making the same are provided, the system comprising a pneumatic source, a pneumatically operated device that produces an output, and a control unit for interconnecting the source to the device. The control unit has an input interconnected to the source and an output interconnected to the device, the control unit having a set point for selecting a desired output of the device. The control unit has a valve unit for controlling the interconnection between the input and the output thereof so as to regulate the pressure value in the output of the control unit. The control unit has a regulating unit for operating the valve unit to tend to produce an output of the device that corresponds to the selected output of the set point.

Abstract: A current-to-pressure (I/P) converter provides an output pressure as a function of the magnitude of a variable input DC current. The I/P converter includes a pressure sensor which produces a feedback signal representative of the output pressure. Based upon the feedback signal and the magnitude of the input DC current, an electrical control signal is produced which controls a device for varying the output pressure. The I/P converter also includes a circuit for generating a time-varying signal which is sent back over the current loop wires through which the input DC current flows. The time-varying signal provides an indication of whether the I/P converter is functioning properly. This permits diagnosis of possible causes of control system malfunctions without having to inspect the I/P converter itself.

Abstract: An extremely accurate and reliable fluid pressure sensor for monitoring process pressure and sensing when predetermined pressure set points or limits have been reached. A Bourdon tube with a pivotally moving lever end responds to the process pressure. When the process pressure is within the desired pressure range, a fluid operated block and bleed relay is operated to provide a first pressure level at its outlet. As the preset pressure point is reached, the relay is operated to provide a change in the outlet pressure level for actuating suitable safety units. A pivoting beam responds to pivoting movement of the Bourdon tube lever arm about the pressure set points and effectively amplifiers or increases such movement to rapidly operate the relay. Snap-acting cap means with a self-aligning disc cap a nozzle port in the relay in response to pivoting beam movement.

Abstract: A pneumatic condition sensing system for reducing the consumption of air supplied by a pneumatic source, the system having a bleed type pneumatic device for bleeding air from a branch line to atmosphere to control the pressure within the branch line in response to a sensed condition, an elongated restriction for connecting the bleed type device to the pneumatic source, the elongated restriction having an air conserving flow versus pressure relationship, and a controller connected to the branch line and responsive to the pressure therein for providing a control function usable in controlling a condition.

Abstract: A pneumatic positioner is provided with a O-shaped vane that is movably supported at the ends of each of its legs. The nozzle has an air outlet proximate to and aligned with the vane. A nozzle, connected to a source of air under pressure, is attached to a disc for rotation about a central stem that extends through the O-shaped recess. The nozzle has an air outlet proximate to and aligned with the vane. The disc is rotatable about the stem to reposition the nozzle relative to the vane so that air issuing from the outlet of the nozzle can impinge upon the vane at different locations along the length of the vane, intermediate the ends of the legs of the vane. One end of the vane is attached to an input and feedback signal mechanism and the opposite end of the vane is connected to a relay center structure.

Abstract: A pneumatic control system, control unit and method of making the same are provided, the system comprising a pneumatic source, a pneumatically operated device that produces an output, and a control unit for interconnecting the source to the device. The control unit has an input interconnected to the source and an output interconnected to the device, the control unit having a set point for selecting a desired output of the device. The control unit has a valve unit for controlling the interconnection between the input and the output thereof so as to regulate the pressure value in the output of the control unit. The control unit has a regulating unit for operating the valve unit to tend to produce an output of the device that corresponds to the selected output of the set point.

Abstract: In a device for converting electric signals into pneumatic signals, a soft-iron core (3) and a coil (2) are arranged stationary. The soft-iron core has an air gap (7) between two pole shoes (5, 6). A permanent magnet (8) is movably arranged within this gap (7) or directly in front of it. The permanent magnet can be fastened, for instance, to one lever arm of a rocker (9). The other lever arm of the rocker (9) is then developed as baffle plate (11) adapted to throttle the stream of air emerging from a pneumatic nozzle (12) to a greater or lesser extent depending on the position of the rocker. The dynamic pressure of this stream of air is fed via a booster (15) to an outlet (20).

Abstract: A fluid pressure regulating valve includes a diaphragm piston reciprocally movable within a valve housing, whereby undesirable diaphragm piston flutter is effectively dampened by use of a dampening member. The diaphragm piston separates a control chamber from an outlet chamber which is in communication with a fluid pressure receiving device. A selectively controllable solenoid valve controls the fluid pressure level in the control chamber. Differences in fluid pressure levels across the diaphragm piston result in the reciprocal movement, thereby, such movement being preconditioned to occur as a function of the fluid pressure level in the control chamber. An inlet valve and an outlet valve each communicate with the outlet chamber and are operated according to the position of the diaphragm piston. Furthermore, the inlet and outlet valves are connected by a connecting rod such that their operation is mutually dependent.

Abstract: An electric signal to pneumatic signal transducer 10 comprises a nozzle 12 that accepts an input pneumatic supply and expels a gas stream 20. A receiver 16 that is spaced from the nozzle is positioned to recover at least a portion of the gas stream. The recovered portion constitutes a pneumatic output signal. The position of a deflector 14 relative to the gas stream is controlled by an electric input signal to aerodynamically deflect the gas stream expelled from the nozzle. The aerodynamic deflection affects the magnitude of the portion of the gas stream recovered by the receiver in a manner having a known relationship to the electric input signal, thereby generating a pneumatic output signal responsive to the electric input signal.

Abstract: An electrical-pneumatic transducer includes a pneumatic relay in which the pressure of the air at the outlet varies in accordance with the back pressure of the air at a bleed nozzle in the relay. This back pressure is changed by the armature of a solenoid with the armature opposing the nozzle outlet and being urged toward the latter with a force responsive to a signal in the form of current flowing through the solenoid coil. The magnitude of the current is correlated with the magnitude of a variable condition. The force on the armature, which is a permanent magnet, is selectively set to calibrate the transducer by means of a second permanent magnet which is axially aligned with the armature and is adjustably movable toward and away from the latter.

Abstract: A positioner-actuator control system includes a pair of relays and a pivotally mounted beam for operation thereof in response to a pneumatic control signal. A summing beam has forces applied to it from an input signal, a controlled device position lever, a zero adjustment and a damping mechanism comprising a pair of flat springs attached to the relay beam and to the summing beam. A clamp is movable along the flat springs to permit user adjustment of the damping force.

Abstract: A circuit for pneumatic controllers, a proportional-action range of which is adjustable, with the circuit including at least one differential amplifier having input pressure chambers being exposed to pressures derived between two throttle resistors respectively inserted in the measured value X input line and the desired value W-input line. All of the resistors are constant and a connecting line is interposed between connecting sections of the resistors, with the connecting line being provided with an adjustable throttle resistor.

Abstract: A pneumatic subbase for modifying the operation of a pneumatic thermostat is disclosed having a first nozzle to be connected to a source of main pressure, a second nozzle for supplying branch output pressure to the device being controlled, a third nozzle connected through the subbase to the first nozzle for supplying main pressure to a thermostat and a fourth nozzle connected to receive the output from the thermostat, the subbase having a dwell relay therein for providing a dwell in the branch output pressure of the second nozzle as a function of the pressure received from the thermostat at the fourth nozzle.

Abstract: A pneumatic converter comprising a bellows having in its interior a coupling plate connecting the two ends of the bellows together at a position offset from the center axis of the bellows.

Abstract: A pneumatic device is arranged for reducing positive feedback and includes a housing having a diaphragm defining a control chamber, the control chamber being connected to an input and having a pressure therein dependent upon an input pressure, the control chamber having a nozzle therein and operatively associated with the diaphragm so that the position of the diaphragm with respect to the nozzle controls the pressure within the control chamber, the nozzle being sloped for substantially reducing positive feedback resulting from bleeding of the pressure from the nozzle into the control chamber and an output connected to the control chamber for providing an output pressure.

Abstract: A fluid signal inverting unit includes a motion balance unit having a lever which operates a valve. The balance lever is supported at the opposite ends by a pilot signal chamber and a feedback signal chamber and an intermediate pivot support is coupled to position a back pressure leakport valve. Each chamber includes an outer matched linear metal diaphragm fixedly connected to the aligned end of the lever. Increases in pilot pressure result in the outward movement of the linear diaphragm and corresponding outward and pivotal movement of the lever. The lever tends to move away from and open the valve resulting in a decrease in the output pressure and an inverted output pressure signal which may be further amplified and transmitted to a flow booster relay, and as negative feedback signal to the feedback chamber. Decrease in pilot pressure results in an opposite action and an increase output pressure.

Abstract: An adjustment mechanism for adjusting the maximum flow rate of conditioned air in an air distribution system controlled by a pneumatic control circuit. An air bladder controls the distribution of air, and the pressure is bled from the bladder under the control of a diaphragm against which pressure is fed back from the downstream side of the bladder. The control orifice through which the bladder pressure is exhausted is formed in the end of an exhaust tube that is axially adjustable. A cam and set screw arrangement serves to extend and retract the exhaust tube to move the control orifice toward and away from the diaphragm for adjustment of the maximum flow rate.

Abstract: A control device having a housing provided with a main lever pivotally mounted thereto by a pivot structure and being operatively associated with a flapper to move the same relative to a leakport in relation to pivotal movement of the main lever. The device has a feedback diaphragm operatively associated with a feedback lever that is pivotally mounted to the housing and is operatively associated with the main lever to cause pivoting thereof upon pivoting movement of the feedback lever by the feedback diaphragm. The device has means for selectively changing the device to be either direct acting or reverse acting.

Abstract: A pneumatic relay responsive to an air input signal whose pressure represents a variable, the relay producing an air output signal proportional thereto. The relay includes an input chamber to which the input signal is fed, this chamber being separated from an output chamber by a diaphragm of elastomeric material. Air from a constant high-pressure supply is fed into the output chamber through an adjustable supply port that is operatively coupled to the diaphragm to cause this port to open to an extent determined by the deflection of the diaphragm in response to the force produced by the pressure of air in the input chamber until a point is reached where the pressure developed in the output chamber attains equilibrium with that in the input chamber.

Abstract: A mixed air conditioning controller is formed as a factory assembled and adjusted unit in a compact housing, with simple and direct input/output field connectors. Various temperature and humidity input devices are field connected to produce a sequenced control of the air dampers and mechanical cooling and heating devices, as well as auxiliary devices. The controller includes a primary input related to room demand, an outside air temperature input, with an interlocked control to the damper, a fan status input, a minimum air supply control and a by-pass switch having a low limit input. The logic network connecting the input/output includes pneumatic switching, pressure selecting and comparing devices of a diaphragm-controlled-orifice construction connected to function as fluidic repeaters, pressure regulating valves and pressure isolating and switching devices. The controller includes a conditioning channel and a damper channel.

Abstract: A self-contained control device for a system having a first source provided with a changeable fluid pressure value and a second source provided with a changeable vacuum value and having a pressure operated control unit that changes its operating condition in relation to the value of the pressure signal directed thereto, the control device having pneumatically operated control means adapted to be operatively interconnected to the sources and the control unit for increasing the pressure signal from the first source to the unit as the pressure value from the first source increases from a first value thereof to a second value thereof and for thereafter decreasing the pressure signal from the first source to the unit as the pressure value from the first source further increases from the second value thereof to a third value thereof. The control means are adapted to produce the signal in substantially the same manner but at different values for different levels of vacuum at the second source.

Abstract: A system having a vacuum source, a pressure source and a pressure operated control device. A pneumatically operated control unit is provided for increasing a pressure signal from the pressure source to the device as the value of the pressure of the pressure source increases from a first value to a second value and for thereafter decreasing the pressure signal from the pressure source to the device as the value of the pressure of the pressure source further increases from the second value thereof to a third value thereof, the control unit producing the signal in substantially the same manner but at different values for different levels of vacuum at the vacuum source thereof. The control unit can include a temperature responsive valve for substantially linearly changing the magnitude of the signal to the device in relation to a certain temperature range.

Abstract: Discloses a pneumatic controller having a proportional band altering unit, a proportional plus integral operation unit, a comparator and a manual-automatic transfer means, wherein the proportional band altering unit is combined with the proportional plus integral operation unit to provide a proportional band altering mechanism which limits input to prevent output of the comparator from being saturated whereby to enable the pneumatic controller to perform the transfer between the manual and automatic modes in a balanceless and bumpless manner.

Abstract: A primary element is connected to a control element of a first fluid pressure relay to move the element to positions at which pressure fluid outputs of relatively small volumes will be generated to represent the element positions. The pressure fluid outputs of the first relay are directed to the input of a second relay which generates pressure values for pressure fluid which are proportional to the first relay outputs in, and at, relatively larger volumes of the pressure fluid.

Abstract: A thermopneumatic actuator of the invention is used to control an automobile heater and/or air conditioner to maintain a desired temperature in the automobile passenger compartment through a mechanical output member of the actuator. The output member is connected to and moved by a diaphragm which is positioned by vacuum introduced from the automobile intake manifold and works against a diaphragm spring. A valve is controlled by a bimetal spring exposed to air from the passenger compartment to modulate the vacuum applied to the diaphragm. A feedback spring connected between the diaphragm and the valve works against the bimetal spring. An aspirator comprising a venturi tube causes air flow from the passenger compartment around the bimetal spring.

Abstract: A system having a vacuum source, a pressure source and a pressure operated control device. A pneumatically operated control unit is provided for increasing a pressure signal from the pressure source to the device as the value of the pressure of the pressure source increases from a first value to a second value and for thereafter decreasing the pressure signal from the pressure source to the device as the value of the pressure of the pressure source further increases from the second value thereof to a third value thereof, the control unit producing the signal in substantially the same manner but at different values for different levels of vacuum at the vacuum source thereof. The control unit can include a temperature responsive valve for substantially linearly changing the magnitude of the signal to the device in relation to a certain temperature range.

Abstract: The invention contemplates improved hydraulic-pressure control apparatus which will proportionally reflect input-signal changes governing a wide range of output pressures. Use of a separate preamplifier stage, between a signal-pressure stage and a power stage, enables the signal pressure to remain essentially unaffected by load reaction or other transients at the power stage. In the forms described, an input electrical signal determines a step-function program of signal-pressure levels, and the power stage includes a relief valve which so diverts system-line flow to a sump as to assure quick and accurate response of system-line pressure to the instantaneous input electrical-signal level, all without system-pressure overshoot.

Abstract: This invention relates to a pneumatic control device having an operating mode selecting means for operating in either the manual or automatic modes. Pneumatic pressure is regulated in the manual mode by a hand operated leakport, and in the automatic mode by a voice coil or other pressure regulating device. The pneumatic input supply, manual pressure regulating means and voice coil all communicate at a common surface. The mode selecting means slides across this common surface to connect together the pneumatic input supply with one of the selected pressure regulating means.