Method of adjusting the pressure balance or a control device, in particular of a servo valve, the requisite adjusting movement being applied by a disc translator.

A piezoelectric ring bender servo valve assembly reduces mechanical wear by removing mechanical components used in prior art servo valves. The assembly does not use torque motor, flapper, and feedback spring. In this manner, no moving parts are required, which reduces maintenance and costs. A pair of piezoelectric ring benders mount adjacently to a pair of nozzles. The piezoelectric ring benders independently regulate the flow of fluid through the nozzles by moving between an open position to enable flowage, and a closed position to restrict flowage. A linear position sensing device measures and provides feedback about the spool position to a valve controller. The valve controller allows the spool valve to move until valve position achieves command position and the force on the spool valve is in equilibrium with pressure difference across spool valve. An H-bridge operable to switch the polarity of a differential pressure applied across to a load.

Provided are methods and systems for controlling a pressure relief valve. An electronic control unit monitors pressure being supplied from a source. If the control unit determines that the monitored pressure is above a threshold pressure, the control unit controls an actuator to move the pressure relief valve to an open position, thereby releasing the pressure from within the system. If the control unit determines that the monitored pressure is at or below the threshold value, the control unit controls the actuator to move the pressure relief valve to a closed position.

A sealing device for a foot therapeutic apparatus includes an airtight sleeve and a sealing member. The airtight sleeve includes a treatment box connecting end and a limb inlet end. The sealing member is fixedly mounted at the limb inlet end. The sealing member includes a tightening band and an annular gas bag located on the outer periphery of the tightening band. The annular gas bag is connected to a gas source. A foot therapeutic apparatus with the sealing device includes a treatment chamber and an electrical chamber. The treatment chamber comprises a treatment box, and the sealing device is arranged on the treatment box. A box opening is arranged at a top of the treatment box, and the treatment box connecting end of the airtight sleeve of the sealing device is hermetically connected to the box opening.

An electropneumatic parking-brake valve unit for an electronically controlled pneumatic brake system has a first supply connection to a compressed air source. A spring brake connection connects to a spring brake cylinder of a vehicle. A parking-brake valve arrangement has a bistable valve switchable between switching states wherein a spring brake pressure can be controllable in dependence upon the switching state. A pneumatically switchable holding valve has a holding-valve connection for a first control pressure and the holding valve is connected between the first supply connection and the bistable valve. The holding valve is under a spring load into a first switching position wherein the bistable valve is connected to a deaerator. The bistable valve switches into a second switching position when the first control pressure exceeds a first threshold value. The bistable valve is connected to the first supply connection.

A gas supply line control system and method for preventing flow reversal due to an upstream pressure drop in a natural gas supply line, the system and method include setting a threshold low pressure for the upstream gas flow, continually sensing the upstream pressure, activating a trigger valve when the upstream pressure falls below the threshold low pressure, and closing a control valve in response to the trigger valve to prevent reversal of flow in the gas supply line.

A solenoid valve assembly with a manual override is provided that includes a solenoid valve housing that is supportive of a valve seat, a plunger-type armature valve element fluidly communicative with a fluid source and initially pressure balanced to remain in a closed position relative to the valve seat and an electromagnet configured to generate a magnetic flux to move the plunger-type armature-valve element into an open position relative to the valve seat. The solenoid valve assembly with a manual override also includes a manual actuation assembly configured to generate an applied force to move the plunger-type armature valve element into the open position relative to the valve seat.

A valve device includes an operating unit, a first pushing member, a plate-like member, a second pushing member, and a valve. The plate-like member includes a plurality of the moment arms arranged at intervals in a circumferential direction. A force point of each of the plurality of the moment arms is pushed by a front end of the first pushing member. The second pushing member has an acted surface receiving a force from an action point of each of the plurality of the moment arms. The plurality of the moment arms are integrally connected by an annular frame portion of the plate-like member where the fulcrum is disposed.

A sealing device for a foot therapeutic apparatus includes an airtight sleeve and a sealing member. The airtight sleeve includes a treatment box connecting end and a limb inlet end. The sealing member is fixedly mounted at the limb inlet end. The sealing member includes a tightening band and an annular gas bag located on the outer periphery of the tightening band. The annular gas bag is connected to a gas source. A foot therapeutic apparatus with the sealing device includes a treatment chamber and an electrical chamber. The treatment chamber comprises a treatment box, and the sealing device is arranged on the treatment box. A box opening is arranged at a top of the treatment box, and the treatment box connecting end of the airtight sleeve of the sealing device is hermetically connected to the box opening.