A servovalve includes a fluid transfer valve assembly comprising a supply port and a control port, a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal, and a drive assembly configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The drive assembly includes a steerable member moveable by an amount determined by the control signal to cause corresponding movement of the valve spool. The drive assembly further includes piezoelectric actuator means configured to move said steerable member in response to the control signal.

A dual control shut off system, such as a dead man system for a blasting system, blasting equipment, or other equipment having both pneumatic and electric safety control circuits, may include an electric dead man's switch or a pneumatic dead man's switch. An embodiment of the dual control dead man system is for wet abrasive blasting systems used for cleaning, preparing surfaces, removing coatings, and/or other abrasive blasting operations. Embodiments of the dual control shut off system provide the ability to conveniently switch between an electric and pneumatic shut off system.

A proportional motion control valve includes an electro-mechanical actuator that provides an infinitely controlled pressure setting in response to an electric signal applied to the electro-mechanical actuator. In another aspect, a proportional motion control valve includes a pilot-operated valve disposed intermediately with respect to a cage and a valve body to fluidly isolate an internal cavity of the valve body from a bore of the cage. The pilot-operated valve is subjected to a hydraulic opening force of pilot fluid that is present in the bore of the cage. A spring is disposed within the internal cavity of the valve body and arranged to subject the pilot-operated valve to a closing spring force.

A hydraulic suspension system includes a suspension cylinder, a pump, and a control valve therebetween. The control valve includes a spool reciprocally movable between a pump flow position and a tank flow position in which a control port of the control valve is in communication with a pump and a tank, respectively. A piloted logic element in fluid communication with and interposed between the control valve and the suspension cylinder is selectively movable between a through-flow position in which fluid can flow in either direction between a chamber of the suspension cylinder and the control port of the control valve and a blocked position in which fluid is prevented from flowing in or out of the chamber of the suspension cylinder. The logic element is biased to the blocking position, moving to the through-flow position when subjected to a crack pressure delivered from the control port of the control valve.

A solenoid valve has a housing defining a first axis and second axis, a solenoid which produces a magnetic field along the first axis, a valve shaft movable between a first position and a second position along the second axis, and a manifold mounted to the housing. The valve shaft is biased toward the first position by a spring and mechanical forces sufficient to overcome the force of the spring are transferred from the solenoid to the shaft by a lever to displace the shaft to its second position. A poppet seal affixed to the shaft, which interacts with a portion of the housing to close an outlet port in the housing, and a spool seal, also affixed to the shaft which interacts with a wall of the manifold defining an exhaust port to route fluid to the desired port. An electronic circuit controls delivery of current to the solenoid to shift and hold the shaft in the second position.

A valve, in particular a pilot-operated proportional pressure control valve, has a valve housing (5) with a pressure supply port (7), a working port (9), and a drain port (11). In the valve housing (5), a main valve piston (15) can be moved by a pilot stage (13) for control of the fluid flow between the pressure supply port (7) and the working port (9). The pilot stage (13) has a valve closing element (43) for a pilot chamber (41). The valve closing element (43) is movable from an open position (OS) into a closed position (SS) by an actuating apparatus (45). The valve closing element (43) can actuate a leakage reduction stage (53).

A pilot actuator is disclosed for use with a valve. The pilot actuator may have a cage with a base end and a tip end, and a pilot bore formed in the cage. The pilot actuator may also have a supply port, a drain port, a first end port, and a second end port each formed in the cage and intersecting with the pilot bore. The pilot actuator may further have a pilot spool slidingly disposed in the pilot bore and movable to selectively connect the supply port and the drain port with the first and second end ports, a follower separate from the cage and disposed at the tip end of the cage, and at least one spring operatively connecting the follower to the cage and to the pilot spool.

A valve (10) includes a first valve housing portion (12) and a second valve housing portion (14). The first valve housing portion and the second valve housing portion are separate components attached together to define a valve housing. The first valve housing portion includes an inner end surface (16) having an opening (18). The second valve housing portion includes an inner end surface (56) having a protruding annular rim (60) with an annular groove (62) and a seal (64) is received in the annular groove. The protruding annular rim including the seal is received in the opening in the inner end surface of the first valve housing portion to define a valve housing.

A flow passage switching unit includes a valve body in which plural ports are formed, a spool arranged slidably in axial directions in the interior of the valve body, a spool drive unit for driving the spool in an A direction, a biasing mechanism that is configured to bias the spool elastically in the interior of the valve body, and a piston section that exerts a force on the spool in a B direction based on the pressure of a first output port.

A stepper motor driven actuator system is provided. The system includes a stepper motor, a cam, and a gearbox system. The gearbox system operatively connects the stepper motor to the cam. The cam rotates in response to stepping of the stepper motor. The system also includes a valve having a control piston located therein. The control piston is configured to translate in response to rotation of the cam. The system further includes a rotary actuator. The rotary actuator is fluidly connected to the valve, and the rotary actuator is configured to rotate the cam in response to translation of the control piston.