In a valve device, travel control valve unit has a communication path causing the lead-out passages of the left and right travel control valve units to communicate with each other, and a spool has a lead-out side land portion configured to cause communication or shut-off of the communication between the lead-out passage and the communication path, a discharge-side land portion configured to cause communication or shut-off of the communication between the actuator passage and the discharge passage, a discharge portion configured to discharge a part of the working fluid led from the supply passage to the lead-out passage to the discharge passage at a movement initial stage of the spool, and a communication portion configured to cause the lead-out passage and the communication path to communicate with each other at a movement final stage of the spool.

The present disclosure describes a fuel system for an engine. The fuel system includes a fuel metering valve, a flow measuring system, and a controller in communication with the fuel metering valve and the flow measuring system. The fuel metering valve is operable to meter a flow rate of fuel based on a stroke of the fuel metering valve. The flow measuring system is configured to measure a mass flow rate of the fuel leaving the fuel system at a bandwidth greater than 20 Hz. The controller is configured to dynamically adjust the stroke of the fuel measuring system based on the mass flow rate of the fuel measured by the flow measuring system to change the flow rate of the fuel.

A gas flow control system for delivering a plurality of gas flows. The gas flow control system has a gas flow path extending from a gas inlet to first and second gas outlets. First and second flow restrictors are operably coupled to the gas flow path. First and second valves are operably coupled to the gas flow path such that when both first and second valves are in a fully open state, flows of gas from the first and second gas outlets are split according to the impedances of the first and second flow restrictors.

An entire fluid supply line or an entire fluid controller constituted by a plurality of fluid control devices is precisely monitored. A fluid controller G accumulating and having a plurality of fluid control devices A. The fluid control devices A include an operation information acquisition mechanism acquiring an operation information in the fluid control devices, an identification information storage 71 storing a self-identification information, and a communication processing unit 72 transmitting the operation information acquired by the operation information acquisition mechanism to an external terminal with the self-identification information stored in the identification information storage 71 at different timings for each of the fluid control devices A.

A valve unit is moveably accommodated in a valve housing having a valve seat. A coil spring is provided at an outer periphery of the valve unit to bias the valve unit in an axial direction of absorbing a backlash between a driving-side screw portion of a driving portion and a valve-side screw portion of the valve unit. Pressure losses of fluid at respective portions are so made to satisfy a relationship of P0P1P2, wherein P0 is a pressure loss of the fluid passing through an outlet port, P1 is a pressure loss of the fluid passing through an axial space formed between the valve unit and the valve seat in a condition that the valve unit is most separated from the valve seat, and P2 is a pressure loss of the fluid passing through an axial gap formed between neighboring spring wire portions or passing through an axial gap formed between the coil spring and the valve seat.

A multistage flow control valve system with a pressure balanced first stage connected to one or more downstream, pressure balanced, intermediate and/or outlet stages configured to accommodate very large pressure drops across the system while maintaining a desired flow rate, and avoiding potentially destructive cavitation within the valves.

A passive thermal control valve comprising a thermal actuator coupled to a valve body having first and second ports. The thermal actuator including an actuator body having an inner bore. An adjustment stop engages the actuator body. A cylinder is received within the actuator body inner bore and the cylinder has a cylinder bore open at one end. An actuator spring within the actuator body biases the cylinder towards the adjustment stop. An actuator rod is at least partially received within the cylinder and has first and second ends. At least a portion of the actuator rod is allowed to extend through the open cylinder bore. A sealing element forms a seal between the actuator rod and the cylinder and defines a sealed chamber within the cylinder. A thermal fluid is contained within the cylinder. A lever mechanism is connected to the valve body and includes a lever having a first end connected to the valve body. A valve spool is connected to a lever second end. The valve spool is arranged and designed to close the first port and allow a system fluid to flow through the second port, close the second port and allow the system fluid to flow through the first port, or allow the system fluid to flow through both the first and second ports.

An example valve includes: a valve body defining a bore, an inlet port, an outlet port, and a signal cavity; a spool movable in the bore to shift between a first position and an intermediate position, where the spool has a first end and a second end, where the outlet port is fluidly connected to the second end, where the valve body defines a spring cavity adjacent the first end of the spool to house a spring, where the first end is subjected to a load-sense pressure signal, and where when the spool is in the first position, the spool disconnects the inlet port from the outlet port and connects the inlet port to the signal cavity; and a valve actuator that, when activated, connects the signal cavity to the second end of the spool to move the spool in the bore from the first position to the intermediate position.

Control flowrate regulating valve for a scroll compressor inside a vehicle air conditioner or a heat pump, the valve at least comprising: a housing; a closing member; and fluid connection parts for a control flowrate of back pressure, high pressure and suction pressure. Fluid connection parts having effective areas, of the closing member, assigned to the fluid connection parts. Control flowrate regulating valve has a fluid connection part, for peripheral pressure, and an effective area of the closing member. It is formed in a fluid-sealing manner for other chambers having high pressure, back pressure and suction pressure, such that the force, obtained from the pressures applied to the closing member, is applied to the closing member to allow the control flowrate, which moves from the high pressure to the suction pressure, to flow in a manner of forming the back pressure. Peripheral pressure is applied to the closing member.

A passive thermal control valve comprising a thermal actuator coupled to a valve body having first and second ports. The thermal actuator including an actuator body having an inner bore. An adjustment stop engages the actuator body. A cylinder is received within the actuator body inner bore and the cylinder has a cylinder bore open at one end. An actuator spring within the actuator body biases the cylinder towards the adjustment stop. An actuator rod is at least partially received within the cylinder and has first and second ends. At least a portion of the actuator rod is allowed to extend through the open cylinder bore. A sealing element forms a seal between the actuator rod and the cylinder and defines a sealed chamber within the cylinder. A thermal fluid is contained within the cylinder. A lever mechanism is connected to the valve body and includes a lever having a first end connected to the valve body. A valve spool is connected to a lever second end. The valve spool is arranged and designed to close the first port and allow a system fluid to flow through the second port, close the second port and allow the system fluid to flow through the first port, or allow the system fluid to flow through both the first and second ports.