The present invention relates to a pressure control valve (30) for open-loop or closed-loop control of a pressure of a compressed fluid in a pilot pressure chamber (12), comprising a valve housing (50) with at least one inlet (41) which can be fluidically connected to the pilot pressure chamber (12), and at least one outlet (43); a wall section (51) which is permanently arranged in the pressure control valve (30) and which wall section has a passage channel (60) through which the compressed fluid can flow, and forms a first valve seat (58); a tappet (52) which is mounted in the valve housing (50) so as to be movable along a longitudinal axis (L) by means of an actuation device (49) that can be energized; a first sealing element (54) which forms a second valve seat (66), is mounted in the valve housing (50) so as to be movable along the longitudinal axis (L) and is biased by means of a first spring (56) against the actuation direction (B) of the actuation device (53) into a closure position in which the first sealing element (54) bears against the first valve seat (58) and can be moved by the compressed fluid in the actuation direction (B); and a second sealing element (64) which is attached to the tappet (52), the second valve seat (66) being arranged axially offset to the first valve seat (58) with respect to the longitudinal axis (L), and a second spring (68), which biases the second sealing element (64) into the first position.

An electro-hydraulic control system actuates a control valve. A control module is controlled via two hydraulic lines and two electrical power lines. The control module uses one of the hydraulic lines as a “supply” line and the other line as a “return” line. The control module includes two normally closed (NC) solenoid valves (SOVs) that are coupled to the electrical power lines and can be controlled from the surface to open or close. The opening or closing of the NC SOVs in cooperation with hydraulic pressure on a “supply” line of the hydraulic lines operates the control valve. A NC hydraulic activated pilot cartridge in the control module can be actuated open, and movement of the control valve in either direction can continue for a short time without energizing either of the NC SOVs, therefore lowering a power demand required by the system.

An electro-hydraulic control system for actuating a control valve includes a control module. The control module is coupled to the surface via two hydraulic lines and an electric line. The control module uses one of the hydraulic lines as an “open” line and the other line as a “close” line. The control module includes a normally closed (NC) solenoid valve (SOV) that is coupled to the electric line and can be controlled from the surface to open or close. The opening or closing of the NC SOV in cooperation with hydraulic pressure on an “open” or “close” line of the hydraulic lines operates (i.e., closes or opens) the control valve.

An electro-hydraulic control system for actuating a control valve includes a control module. The control module is coupled to the surface via two hydraulic lines and an electrical power line. The control module uses one of the hydraulic lines as an “open” line and the other line as a “close” line. The control module includes a normally closed (NC) solenoid valve (SOV) that is coupled to the electrical power line and can be controlled from the surface to open or close. The opening or closing of the NC SOV in cooperation with hydraulic pressure on an “open” or “close” line of the hydraulic lines operates (i.e., closes or opens) the control valve.

An electro-hydraulic control system for actuating a control valve includes a control module. The control module is coupled to the surface via at least one hydraulic line and two electrical power lines. The control module uses one of the hydraulic lines as a “supply” line and the other line as a “return” line if included. Each hydraulic line of the at least one hydraulic lines can be used as an “open” line or a “close” line to open or close the control valve. The control module includes two normally closed (NC) solenoid valves (SOVs) that are coupled to the electrical power lines and can be controlled from the surface to open or close. The opening or closing of the NC SOVs in cooperation with hydraulic pressure on a “supply” line of the hydraulic lines operates (i.e., closes or opens) the control valve.

A continuous variable transmission (CVT) hydraulic pressure control device includes: a pressure regulation valve regulating an operation pressure of oil supplied to a friction element of a forward-rearward device; and a switch valve to respectively switch oil discharge paths through which the oil supplied to the friction element is discharged, respectively by a pilot pressure from the pressure regulation valve and an elastic force of a return spring. In particular, the oil discharge paths switched by the switch valve have oil flow resistances different from each other.

A valve device including an outlet port, a first valve unit with a first valve element for setting a first throttle opening for influencing a first airflow of pressurised air which is to be output at the outlet port or is to be released via the outlet port, a first throttle control loop for the closed-loop control of the first throttle opening according to a first setpoint, a pressure control loop for the closed-loop pressure control of an outlet pressure present at the outlet port to a pressure setpoint amid the use of a first throttle control loop as a subordinate control loop, wherein on closed-loop pressure control the pressure control loop specifies a first throttle setpoint to the first throttle control loop as the first setpoint, wherein the valve device is further configured to provide a throttle setting function and, within the throttle setting function, to limit the first throttle opening to a first limitation value and/or within the throttle setting function to specify a first direct setpoint which does not come from the closed-loop pressure control, to the first throttle control loop as the first setpoint.

A fluid pressure control apparatus includes a proportional solenoid valve having a solenoid portion and a valve portion operatively connected between a fluid inlet port and a fluid outlet port fluidly coupled to a pressure sensor. An electronic controller receives a first signal from the pressure sensor, receives a second signal corresponding to a pressure set point, and outputs a control signal to the solenoid valve. A flameproof/explosion proof or pressurized/purged enclosure houses the electronic controller and the solenoid portion of the solenoid valve, and a manifold block mounted to the enclosure covers and closes an opening of the enclosure. The manifold block includes internal passageways connecting the valve portion of the solenoid valve between the fluid inlet port and the fluid outlet port. The pressure sensor is arranged outside the enclosure, with the first signal from the pressure sensor being conducted into the enclosure via a fluid-tight electrical feedthrough.

A fluid compressor system having a pneumatic inlet/blowdown valve assembly that utilizes pneumatic pressure and vacuum available in the fluid compressor system for the actuation of an inlet valve and a blowdown valve. The actuation of the inlet valve and the blowdown valve is synchronized via a piston-cylinder actuator having a first piston and a second piston axially connected. The pneumatic blowdown/inlet valve assembly uses a first stage vacuum pressure to actuate the first piston and the second piston from an idle state where the inlet valve is closed to stop a flow of working fluid into the fluid compressor system and the blowdown valve is open to depressurize the fluid compressor system to an actuated state where the inlet valve is open to allow the flow of working fluid into a first airend and the blowdown valve is closed to allow a pressure buildup in the fluid compressor system.

A transmission hydraulic control system includes a manual valve, a default valve, and a clutch prime valve. The manual valve allows fluid flow from a pressurized line to a drive line when the manual valve is open (when a transmission is in drive or reverse). The manual valve prevents fluid flow from the pressurized line to the drive line when the manual valve is closed (when the transmission is in neutral or park). The clutch prime valve allows fluid to flow from the pressurized line to the drive line, and thereby bypass the manual valve, when the manual valve is closed and the clutch prime valve is open. The default valve allows fluid bypassing the manual valve to flow to prime a clutch of the transmission when the default valve is open. The clutch prime valve prevents fluid from bypassing the manual valve when the clutch prime valve is closed.