A pilot operated check valve is configured to be positioned inside a fluid supply tube connected between an air supply manifold and an air zone located on a support surface of abed. The pilot operated check valve includes a body having an air inlet and an air outlet connected by an air passageway. The pilot operated check valve also includes a valve member configured to move between an open position and a closed position to block air flow through the passageway. Additionally, the pilot operated check valve includes a push rod having a first end coupled to the valve member to unseat the valve member when the valve member is in its open position and a second end. The pilot operated check valve includes a diaphragm located in a chamber of the body adjacent the second end of the push rod. The pilot operated check valve further includes an inlet port configured to be coupled to the manifold to admit pressure against the diaphragm. The body is formed to include a vent hole located on an opposite of the diaphragm from the inlet port. The vent hole is formed in communication with the chamber to permit air passing into the chamber from the air passageway to vent to atmosphere.

Air fluidized bed

A fluid-dispensing device comprises substrate (212) and a plurality of nozzles (204) formed in the substrate (212). Each nozzle has (204) has an open-ended tip and a fluid-conducting channel (220) between the tip and a source of fluid. A non-conducting spacer is on the substrate (212) and electrically isolates a gate electrode (208) from the substrate (212). The gate electrode is located adjacent to the tip of at least one of the nozzles (204) to effect dispensing of the fluid in that nozzle (204) in response to a voltage applied between the gate electrode (208) and the nozzle (204) or fluid in the nozzle (204). The gate electrode (208) includes a plurality of individually addressable gate electrodes used for selectively actuating nozzles (204).

System and method of micro-fluidic handling and dispensing using micro-nozzle structures

A flow setting assembly is provided to permit field adjustment of an electronically actuated flow control valve, particularly a pressure independent characterized control valve (PICCV). In a preferred form, flow can be field adjusted by using a hex tool. Therefore, the maximum flow can be increased or decreased within the valve's adjustable flow range. As with all high close-off valves that employ a ball in their design, the ball passes well into the seat when rotated to the actuator's zero-degree position. Therefore, there is an amount of travel within the first degrees of ball rotation that passes back over this seat. The flow setting assembly eliminates this excess rotation (12°) resulting in a closed position that is offset to improve control resolution and system accuracy. This offset continues to allow the high close-off rating of 200 PSI. MFT actuators electronically adjust to and maintain the 2-10 Volt control signal at the reduced angle, as well as the 100 second running time and feedback signal. On floating point (−3) actuators, the running time is constant but dependent on the overall angle of rotation.

A field adjustable control valve assembly and field adjustment module

This disclosure relates generally to valves, and more particularly, to gas valve assemblies. In one example, a valve leakage test may be performed on a valve assembly including a valve body with a first valve and a second valve, where the valves may be positioned across a fluid path in the valve body with an intermediate volume between the valves. A pressure sensor may be in fluid communication with the intermediate volume and may sense a measure that is related to the pressure in the intermediate volume. The pressure sensor may communicate with a controller to determine a measure that is related to a pressure change in the intermediate volume and compare the measure that is related to a pressure change to a first and/or second threshold value. The controller may output a signal if the measure meets and/or exceeds the first and/or second threshold value.

Gas valve with valve leakage test

This disclosure relates generally to valves, and more particularly, to gas valve assemblies. In one example, a valve assembly may be configured to perform a valve proving test as part of an operational cycle of a combustion appliance coupled to the valve assembly. The valve assembly may include a valve body having a fluid path, first and second valve sealing members translatable between an opened position and a closed position, and one or more pressure sensors in fluid communication with an intermediate volume of the fluid path between the first and second valve sealing members. A valve controller may be in communication with the pressure sensor and may monitor a measure related to a pressure change rate in the intermediate volume. The valve controller may then output a signal if the measure related to a pressure change rate in the intermediate volume meets and/or exceeds a threshold value.

Gas valve with electronic valve proving system

An extended range proportional valve which can control rates of mass flow over continuous low, intermediate and high ranges has a pilot member mounted on an armature of a solenoid which can be dithered onto and off of a pilot opening in a main valve member which seals a main valve opening to control mass flow rates over the low range by varying the duty cycle and/or frequency of a pulse width modulated current in the solenoid coil. Intermediate and high flow rates are achieved by dithering the pilot valve member with a duty cycle and/or frequency sufficient to raise the main valve member relatively short and relatively long respective distances from the main valve seat.

Paul W Freisinger

Papers

Extended range proportional valve

Proportionaldurchströmventil mit erweitertem Strömungsbereich