A sequentially operated hydraulic valve for regulating a hydraulic fluid pressure from a single pressurized hydraulic fluid source to two different regulated pressures controlled by a single linear spring and by varying the position of end of the spring relative to the other end of the spring.

Hydraulic valves for dampening pressure spikes and associated methods are disclosed herein. In one embodiment, a hydraulic valve for dampening pressure spikes includes: a spool configured to move axially inside the hydraulic valve; and a sleeve configured to at least partially house the spool. A location of the spool with respect to the sleeve may determine a flow of a working fluid through the hydraulic valve. A viscous damper is at least partially housed inside an opening in the spool, and a viscous friction between the viscous damper and the opening in the spool slows a motion of the spool.

A proportional pressure controller includes a body having inlet, outlet, and exhaust ports. A fill valve communicates with pressurized fluid in the inlet port. A dump valve communicates with pressurized fluid from the fill valve. An inlet poppet valve opens by pressurized fluid through the fill valve. An exhaust poppet valve when closed isolates pressurized fluid from the exhaust port. An outlet flow passage communicates with pressurized fluid when the inlet poppet valve is open, and communicates with the outlet port and an exhaust/outlet common passage. An isolation valve assembly selectively isolates fluid flow to and from the inlet port or the exhaust port to achieve a zero pressure condition.

A valve unit has a main valve and a pilot valve device which is applied thereto, wherein the pilot valve device includes a first pilot valve which is arranged in a valve longitudinal direction between the main valve and a second pilot valve. The main valve can be actuated by way of a pilot fluid through a first pilot working channel which is connected to the first pilot valve and through a second pilot working channel which is connected to the second pilot valve. The second pilot working channel passes through a first pilot valve housing of the first pilot valve, wherein it has a receiving space channel section which passes through an actuation member receiving space of a hand actuation device which is formed in the first pilot valve housing and in which a manually actuatable hand actuation member is arranged. In this manner the valve unit can be realised with a low construction width.

There is provided a spray unit for a remotely operable spray apparatus. The spray unit is configured to spray a material having first and second material components. The spray unit comprises a first material inlet for receiving the first material component, a second material inlet for receiving the second material component, and a spray component comprising a mixing chamber and a spray orifice. The spray component is movable between a spraying position in which the mixing chamber is in communication with the first and second material inlets such that the first and second material components enter the mixing chamber and are sprayed via the spray orifice, and a non-spraying position in which the mixing chamber is closed from the first and second material inlets. The spray unit further includes a pneumatic actuator operable to move the spray component between the spraying position and the non-spraying position, and a remotely operable electric actuator arranged to control operation of the pneumatic actuator.

A valve arrangement has two main valves which are each preloaded by a spring device into a first switching position, and which can each be switched into a second switching position by means of an assigned pilot valve. The pilot medium required for switching is provided with a pilot pressure at a pilot connection of each pilot valve. The main valves are each equipped with a working valve section each of which are fluidically connected to one another. In addition, each main valve contains a monitoring valve section. The monitoring valve sections are designed to provide the venting of at least one pilot connection when the two main valves are in different switching positions. This allows a fluid-actuated actuator to be controlled in accordance with high safety standards.

A downhole tool includes a hydraulically operated actuation device to actuate the downhole tool and a control system that regulates flow of hydraulic fluid to the actuation device. The control system includes a pilot module and a power module. The power module has a first solenoid valve and a second solenoid valve fluidly coupled to a pressure source and a fluid return. The power module is fluidly coupled to the actuation device at an output line and a power line. A first power module check valve is arranged in the power line, a second power module check valve is arranged in a control pressure return line fluidly coupled to the fluid return, a first input communicates with the first solenoid valve, and a second input communicates with the second solenoid valve. A pilot-operated check valve is actuatable in response to a pilot signal to drain hydraulic fluid from the power module.

A valve includes an inlet and an outlet; a body including a first seat and a second seat; a cavity in the body; a piston positioned in the cavity; and a pilot ball adjacent the piston and that is disposed in a pilot seat, and a rear surface of the piston butts against the pilot seat at a maximum open position of the piston. Each of the first seat and the second seat is a seat that is a mechanical stop that prevents the piston from extending further than the closed position. The piston includes a flat front face that contacts the first seat when in the closed position, and a nose extension that extends outward and away from a center portion of the front face, and the nose extension has an opening through a center of a front surface thereof.

An improved servovalve for a seismic vibrator or vibration machine which includes a left additional passageway conducting a portion of sampled pressure from a left cylinder pressure chamber to only a portion of the right end drive surface of the spool, wherein the portion of the right end drive surface is less that of the entirety of the right end drive surface; and a right additional passageway conducting a portion of sampled pressure from a right cylinder pressure chamber to only a portion of the left end drive surface of the spool, wherein the portion of the left end drive surface is less that the entirety of the left end drive surface; thereby providing at least two additional passageways configured to provide linear proportional pressure feedback in spool movement control.

A valve assembly having a plurality of fill valves that permit a fluid to flow from a fluid inlet into an interior flow path to increase a pressure of the fluid output from a fluid outlet, and a plurality of dump valves that permit the fluid to flow from the interior flow path to an exhaust to reduce the pressure of the fluid output from the fluid outlet. The valve assembly includes a controller that is configured for receipt of a command signal including a desired pressure of the fluid to be output from the fluid outlet, and is configured for receipt of a signal from a pressure sensor that is indicative of an actual pressure of the fluid output from the fluid outlet, wherein based on a comparison of the command signal with the signal indicative of the actual pressure, the controller is configured to selectively open and close each of the fill valves and each of the dump valves until the actual pressure is equal to the desired pressure.