A hydraulic valve assembly having a regeneration circuit, where the hydraulic valve assembly is switchable between a regenerative mode and a non-regenerative mode as the valve assembly supplies fluid to operate a hydraulic device. The hydraulic valve assembly may be automatically switchable between the regenerative mode and the non-regenerative mode, such as by utilizing a pressure control valve in the hydraulic circuit that is activatable at a predetermined pressure setpoint, or by utilizing a variable pressure reducing valve that actuates a spool in the hydraulic circuit. In other embodiments, the hydraulic valve assembly may be manually switchable between the regenerative mode and non-regenerative mode by utilizing a valve member operatively coupled to a solenoid in cooperation with one or more check valves in the regeneration circuit.

The “factory installed” pressure regulator valve of an automotive transmission is replaced by a pressure regulator valve having two separate valve components conjointly movable together in a bore. A protrusion or protuberance extending from the center of one end of one of the valve components defines a fulcrum which abuts against an adjacent end of the other valve component as the two valve components move conjointly and in direct contact with each other within the bore during operation of the pressure regulator valve. Preferably, an opening is provided in a land in one of the valve components to vent hydraulic fluid (transmission oil) to prevent a pressure build-up in the bore which might separate the two valve components from each other during reciprocating movement of the valve components in the bore.

A hydraulic control loop controls a hydraulic adjusting cylinder. The cylinder has a cylindrical housing and a displaceable piston therein. The piston divides the housing interior into a first and a second hydraulic chamber. A first hydraulic valve supplies the first hydraulic chamber with hydraulic fluid. A hydraulic pressure of the first hydraulic chamber is adjustable by controlling the first hydraulic valve. A second hydraulic valve supplies the second hydraulic chamber with hydraulic fluid. A hydraulic pressure of the second hydraulic chamber is adjustable by controlling the second hydraulic valve. A control device controls the two hydraulic valves. In a position control state, the second hydraulic valve is controlled by a position control signal dependent on the working position of the piston and the first hydraulic valve is controlled by an adjusted position control signal, that is generated on the basis of the position control signal.

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.

Various embodiments provide a leaching solution monitoring module comprising a first leaching solution distribution system interface, a flow meter in fluid communication with the first leaching solution distribution system interface, the flow meter in fluid communication a 3-way pressure regulator, and a second leaching solution distribution system interface in fluid communication with the 3-way pressure regulator.

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 handheld system includes a reference pressure source configured to generate a reference pressure. The handheld system also includes a primary pressure source coupled to the reference pressure source. The primary pressure source is configured to generate a primary pressure in a primary pressure range. The primary pressure is less than the reference pressure, and the primary pressure is induced by the reference pressure source. The handheld system also includes a secondary pressure source coupled to the primary pressure source. The secondary pressure source is configured to generate a secondary pressure in a secondary pressure range. The secondary pressure is less than the primary pressure, and the secondary pressure is induced by the primary pressure source.

A piston for an electromagnetically actuatable hydraulic valve wherein the piston is configured cylindrical and axially movable along a central opening that extends along a longitudinal axis of a housing of the electromagnetically actuatable hydraulic valve, wherein plural connections of the housing are opened or closed according to a position of the piston wherein the plural connections are flow connected with the central opening, wherein the hydraulic valve is hydraulically actuatable by a signal element, wherein a damping system is provided for reducing oscillations of a signal pressure of the signal element that impacts the piston, and wherein the damping system is configured in the piston that includes a receiving cavity for receiving the damping system.

A solenoid device including pressure altering means for altering an output pressure of the solenoid device; and an actuator for providing an actuating signal to said pressure altering means; wherein the solenoid device further includes a sensor arranged to sense a control value of the solenoid device, and a controller which receives a request and is arranged to control delivery of power to the actuator with feedback from the sensor until the control value meets the request.

Various embodiments provide a leaching solution monitoring module comprising a first leaching solution distribution system interface, a flow meter in fluid communication with the first leaching solution distribution system interface, the flow meter in fluid communication a 3-way pressure regulator, and a second leaching solution distribution system interface in fluid communication with the 3-way pressure regulator.