A pressure regulator includes an outlet pressure sensor, loading and unloading electromagnetic valves, and a regulator control circuit operatively connected to the loading and unloading electromagnetic valves and configured to pilot the loading and unloading electromagnetic valves to cancel an error signal given by a difference between an inlet signal corresponding to a desired outlet pressure and a feedback signal provided by the outlet pressure sensor. The pressure regulator includes an engaging current analysis circuit to detect and store reference characteristics of the engaging current of the solenoid of the loading electromagnetic valve in a stable inlet pressure condition, monitor the engaging current to detect any variation of its characteristics with respect to the corresponding reference characteristics, and, in the event of variation, provide a pilot modulation signal to at least one of the loading or unloading electromagnetic valves or a pressure variation signal to the regulator control circuit.

A fluid controller includes a piezoelectric pump, a valve, and a cuff. The valve includes a first valve housing, a diaphragm, and a second valve housing. The second valve housing has a second air hole, a third air hole, and a first valve seat. The second air hole connects to the internal space of the cuff. The third air hole connects to the outside of the fluid controller. The first valve seat is formed around the third air hole. Together, the second valve housing and the diaphragm form a first flow passage. The first flow passage connects the second air hole and the third air hole to each other. The second valve housing has a protruded portion protruding toward the diaphragm and providing a portion of the first flow passage. The shortest distance between the protruded portion and the diaphragm is less than the diameter of the third air hole.

A degradation detection system includes: a storage that stores measured values of command pressure and measured values of response pressure; and a simulator that calculates, using a physical model, the response pressure in accordance with the command pressure, thereby obtaining a waveform of the calculated response pressure corresponding to a waveform of the command pressure in a case in which the command pressure is changed. A waveform identifier identifies a waveform of the calculated response pressure that matches a waveform of the detected response pressure. A degradation identifier identifies a degraded component of a pressure regulating valve from a value of parameter acquired by the waveform identifier and a normal range defined for the parameter.

Example embodiments relate to microfluidic devices for controlling pneumatic microvalves. One embodiment includes a microfluidic device for independently controlling a plurality of pneumatic microvalves. The microfluidic device is couplable to a pressure source. The microfluidic device includes a first substrate. The microfluidic device also includes a flexible membrane covering the first substrate. Additionally, the microfluidic device includes a second substrate covering the flexible membrane. Further, the microfluidic device includes one or more fluidic channels at least partially defined in the first substrate. In addition, the microfluidic device includes a pressure couplable to the pressure source and branching into a plurality of pressure channels. Still further, the microfluidic device includes at least one pressure control switch per pressure channel.

Example embodiments relate to microfluidic devices for controlling pneumatic microvalves. One embodiment includes a microfluidic device for independently controlling a plurality of pneumatic microvalves. The microfluidic device is couplable to a pressure source. The microfluidic device includes a first substrate. The microfluidic device also includes a flexible membrane covering the first substrate. Additionally, the microfluidic device includes a second substrate covering the flexible membrane. Further, the microfluidic device includes one or more fluidic channels at least partially defined in the first substrate. In addition, the microfluidic device includes a pressure couplable to the pressure source and branching into a plurality of pressure channels. Still further, the microfluidic device includes at least one pressure control switch per pressure channel.

A first flow path is connected to an inlet for introducing gas into a microvalve. A second flow path is connected to an outlet for allowing gas to flow out of the microvalve. A third flow path is for introducing a pneumatic fluid into the microvalve. A negative pressure generation mechanism (a pump) is for generating a negative pressure on the second flow path to suck gas from the first flow path forward the second flow path via the microvalve. A pressure adjustment mechanism (a connection flow path and a valve) is for reducing a pressure difference between the second flow path and the third flow path to prevent the inlet and the outlet from being blocked by a diaphragm layer in response to the negative pressure generated on the second flow path side.

A first flow path is connected to an inlet for introducing gas into a microvalve. A second flow path is connected to an outlet for allowing gas to flow out of the microvalve. A third flow path is for introducing a pneumatic fluid into the microvalve. A negative pressure generation mechanism (a pump) is for generating a negative pressure on the second flow path to suck gas from the first flow path forward the second flow path via the microvalve. A pressure adjustment mechanism (a connection flow path and a valve) is for reducing a pressure difference between the second flow path and the third flow path to prevent the inlet and the outlet from being blocked by a diaphragm layer in response to the negative pressure generated on the second flow path side.

A fluid valve assembly having a central bore and a stem axially-movable within the central bore and actuated by an axial pilot force and an axial counter force. An inner supply pressure chamber is provided to retain a stabilized supply pressure providing the axial counter force affecting on the stem. A seal member is arranged coaxially with the stem between the inner supply pressure chamber and an outer supply pressure chamber which is connected to a supply pressure input line. A metering edge is arranged coaxially with the stem to control fluid flow from the outer supply pressure chamber to an actuator chamber. Means are provided to stabilize the supply pressure in the inner chamber against sudden pressure drops in the outer supply pressure chamber.

A fluid valve assembly having a central bore and a stem axially-movable within the central bore and actuated by an axial pilot force and an axial counter force. An inner supply pressure chamber is provided to retain a stabilized supply pressure providing the axial counter force affecting on the stem. A seal member is arranged coaxially with the stem between the inner supply pressure chamber and an outer supply pressure chamber which is connected to a supply pressure input line. A metering edge is arranged coaxially with the stem to control fluid flow from the outer supply pressure chamber to an actuator chamber. Means are provided to stabilize the supply pressure in the inner chamber against sudden pressure drops in the outer supply pressure chamber.

A bleed valve for use in a gas turbine engine of an aircraft includes a high-pressure cavity coupled to a valve housing, which includes a valve seat configured to be sealed by a system poppet. The system poppet is operably coupled to a shaft that is itself coupled to a movable end of a bellows, which is positioned within the high-pressure cavity. The opening and closing of the valve is controlled by at least one cavity air port that is configured to inject a first fluid into the high-pressure cavity, thus compressing the bellows, and by a servo air port that is configured to inject a second fluid directly into the bellows, to expand it.