A discharge pressure scale (30) includes a valve housing (41) having a functional connector (A), a return flow connector (T) and a user connector (28). A valve piston (52) is guided such that it moves longitudinally against the effect of an energy accumulator (42), moving from a respective opening or regulating position, against a valve seat (94), into a closed position. The user connector (28) and return flow connectors (T) are separated from one another. The fluid pressure present at the user connector (28) can be guided onto a pressure-active surface (A.sub.1*) of the valve piston (52) by a pressure compensation device (70) in such a way that it moves into its respective opening or regulating position in a pressure-compensated manner due to the force of the energy accumulator (42).

An example valve includes: a first port configured to be fluidly coupled to an actuator; a second port configured to be fluidly coupled to a reservoir; a third port configured to provide an output pilot fluid signal and receive an input pilot fluid signal; a fourth port configured to be fluidly coupled to a source of fluid; a pilot poppet configured to be subjected to a first fluid force of fluid received at the first port and configured to be subjected to a second fluid force of the input pilot fluid signal; a solenoid actuator sleeve that is axially movable between an unactuated state and an actuated state; and at least one setting spring configured to apply a biasing force on the pilot poppet.

A poppet switch valve device includes a valve body, a first valve rod including a first valve member, a second valve rod including a second valve member, and a solenoid. When a jig engages with an engagement portion of the first valve rod and rotates the first valve rod so that an internally-threaded hole formed in the first valve rod engages with and moves forward and backward relative to an external thread formed on an outer circumferential surface of the second valve rod, the first valve rod is moved relative to the second valve rod in the axial direction. The poppet switch valve device further includes a restriction portion configured to restrict movement of the first valve rod relative to the second valve rod in the axial direction after the first valve rod is moved relative to the second valve rod in the axial direction using the jig.

A hose end regulator for regulating pressure in fluid includes a main body having a fluid inlet and fluid outlet. A poppet moves between an open position to permit fluid to flow through the fluid outlet and a closed position to militate against fluid flowing through the fluid outlet. A primary spring permits the poppet to move between the open position and the closed position. A flow maximizer minimizes movement of the primary spring until a predetermined fluid pressure is reached within the main outer body.

A logic valve for management of a hydraulic actuator comprising: a valve body with a hollow seat which extends along a work direction and communicates with a first port adapted for receiving a pressurized working fluid, a second port adapted for fluidly coupling with an operating chamber of the hydraulic actuator, and a third port adapted for discharging the working fluid; a slider within the hollow seat movable along the work direction; and a spring between the valve body and the slider and oriented to act on the slider along the work direction in the direction away from said third port, wherein the slider is movable between a first operating configuration fluidly coupling the second and third ports and excluding fluid communication between them and the first port, and a second operating configuration fluidly coupling the first and second ports and excluding fluid communication between them and the third port.

A valve arrangement for hydraulic control of a piston-cylinder of a power switch contains a main stage having a first main valve and a second main valve, and a pilot stage having at least one pilot valve. In order to permit the first main valve to remain securely in the opened state, even in the event of pressure oscillations, the main valve has a total of four control surfaces, of which a second and a third control surface operate in a closing manner and a fourth control surface operates in an opening manner. For this purpose, the second control surface is connected to the high-pressure line, the third control surface is connected to the low-pressure line, and the fourth control surface is connected to the output-side valve connection of the first main valve.

A valve includes an inlet and an outlet, a body including a first seat and a second seat, wherein the first seat and second seat are spaced apart from each other at a predetermined distance, a cavity in the body, a piston positioned in the cavity, wherein the piston rests against the first seat and the second seat when in the closed position, and a pilot ball adjacent the piston.

A relay valve configured according to the various embodiments as described herein advantageously provides consistent, reliable start point pressures for both supply and exhaust functionalities. To achieve this, the relay valves described herein utilize a plurality of diaphragms to neutralize any variable forces due to pressure in an actuator and, optionally, a supply connected to the relay valve.

Provided is a swing-back preventing apparatus capable of preventing a hydraulic actuator in a stop state from operating by undesired load. The swing-back preventing apparatus includes a housing, a piston, and a pair of biasing members. First and second spaces are formed between the piston and the housing, and the piston includes a pair of communication passages that are communicable with first and second spaces. When the piston is located at a first offset position, the first space is blocked from a first port. When the piston separates from the first offset position, the first space is connected to the first port. When the piston is located at a second offset position, the second space is blocked from a second port. When the piston separates from the second offset position, the second space is connected to the second port. When the piston is located at a position on the first offset position side of a neutral position, a first communication passage is connected to the first space. When the piston is located in a range from the neutral position to the second offset position, the first communication passage is blocked from the first space. When the piston is located at a position on the second offset position side of the neutral position, a second communication passage is connected to the second space. When the piston is located in a range from the neutral position to the first offset position, the second communication passage is blocked from the second space.

An example valve includes: a housing having a first longitudinal cavity therein; a sleeve disposed, at least partially, in the first longitudinal cavity, where the sleeve has a second longitudinal cavity therein, and includes a first seat formed as a protrusion from an interior peripheral surface of the sleeve; a poppet mounted within the second longitudinal cavity and configured to move axially therein; and a bushing mounted, at least partially, in the second longitudinal cavity, such that the bushing is floating and is allowed to move axially in the second longitudinal cavity, where the bushing is hollow and defines a first port at a distal end of the bushing and defines a second seat at a proximal end of the bushing, and where the sleeve defines a second port and a third port disposed on an exterior peripheral surface of the sleeve.