A flow rate controller and a drive device are provided with a cylinder flow passage connected to an air cylinder; a main flow passage for supplying air to and discharging air from the air cylinder; an auxiliary flow passage that has a first throttle valve and through which exhaust air discharged from the air cylinder passes with a smaller flow rate than that of the main flow passage; a switch valve that switches between a first position in which the cylinder flow passage communicates with the main flow passage and a second position in which the cylinder flow passage communicates with the auxiliary flow passage; and a pilot air adjustment part that guides a portion of the exhaust air from the air cylinder as pilot air to the switch valve.

Systems and apparatuses include a solenoid valve including a first coil, a second coil coupled to the first coil, a banjo fitting coupled to the second coil, a spool housing coupled to the banjo fitting so that the first coil and the second coil are selectively rotatable about the spool housing, a spool received within the spool housing, and an armature received within the first coil and the second coil and including a spool actuator coupled to the spool.

A method of controlling an actuator includes switching a primary solenoid valve to a first mode to fluidically connect a supply pressure source to a control chamber of a pilot valve. A fluid from the supply pressure source is directed through the primary solenoid valve to fill the control chamber of the pilot valve and put the pilot valve in a first position. The first position fluidically connects a second chamber of the actuator to a return pressure source. The actuator includes a cylinder between the first chamber and the second chamber and a rod attached to the cylinder. The fluid from the supply pressure source is directed into the first chamber of the actuator to move the cylinder and the rod in a first direction while the pilot valve is in the first position.

A valve device that changes the direction of flow of a hydraulic fluid supplied to and discharged from a cylinder mechanism to actuate the cylinder mechanism, the valve device including: a control valve including a main spool axially movable between different positions; a lock valve including a plunger and a pressure chamber; and a selector valve including a selector spool operable in conjunction with the main spool to axially move between different positions, the selector spool being located adjacent to the main spool and having an axis crossing an axis of the main spool.

An air cylinder in which a flow rate controller is built in, has a head cover and a rod cover. A pilot air adjustment unit guides exhaust air to a switch valve of the flow rate controller as pilot air, and the switch valve is switched by an increase in the pressure of the pilot air.

A four-position switching valve includes first and second pistons for driving a spool in a valve body, and a spool moving mechanism part that moves the spool to first and second intermediate switching positions between one-end side and the other-end-side switching positions. The spool moving mechanism part includes a compression spring that moves the spool back in the opposite direction by moving to the switching position on one end side and the other end side of the spool. The compression spring moves the spool to the first intermediate switching position when the spool moves to one-end-side switching position and the pressure on the second piston is released, and moves the spool to the second intermediate switching position when the spool moves to the other-end-side switching position and the pressure on the first piston is released.

A bistable hydraulic solenoid valve has a valve spool that transitions between two positions, remaining in one of the two positions under an attractive magnetic force when the solenoids are not energized. The valve spool has a first permanent magnet attached to one end and a second permanent magnet attached to the other end, so that the first permanent magnet faces a first solenoid, and the second permanent magnet faces a second solenoid. The first solenoid is energized to have a first polarity, and the second solenoid is energized to have an opposite polarity to concurrently push and pull the valve spool within the valve body between a first position and a second position, the first position establishing a first flow path and the second position establishing a second flow path through the valve body and valve spool so as to enable flow of hydraulic fluid.

Embodiments of the disclosure relate to a system designed to compensate for flow disturbances when changing a flow rate in the system. The system includes a flow source device having an inlet and an outlet. The inlet is configured to receive fluid at a first pressure, and the outlet is configured to output the fluid at a second pressure that is higher than the first pressure. The system also includes a fluid control device having an inlet port and a drain port. The inlet port of the fluid control device is configured to receive flow from the outlet of the flow source device. Further, the system includes a constant flow regulator configured to provide a leakage flow to a drain output. The constant flow regulator is configured to decrease the leakage flow in response to the drain port of the fluid control device.

A hydraulic valve comprises a proportional piloted valve that controls pressure and includes means for restricting pilot flow through the pilot flow passage. The means for restricting pilot flow defines a restriction in the pilot flow passage when a movable spool disposed in an axial bore of the body of the valve is in a neutral position. The restriction varies as a function of spool movement such that flow of hydraulic fluid through the pilot flow passage is variably restricted as a function of the position of the spool over its range of travel.

A sub-plate mounted valve for installation in a sub-plate or manifold for controlling hydraulic systems, such as subsea blowout preventers. A spool (123) disposed within the valve is movable between an open position in which fluid flow is permitted from a supply port (108) of the manifold to a function port (106) of the manifold, and a closed position in which fluid flow is permitted between a return port (110) of the manifold and the function port (106). The spool (123) is moved between the open and the closed position by supplying pressurized fluid to a piston (126) disposed on the outside surface of the spool. One or more springs (130) may also act on the piston to bias the spool into the open or the closed position. To facilitate proper alignment of the valve within the manifold, the valve may be rotated within the manifold to align indicators (450, 452) corresponding to particular features of the manifold and the valve.