A valve signature diagnosis and leak testing device includes a spool valve operatively connected to a pilot valve, the pilot valve being configured to position the spool valve to one of an open position and a closed position. A blocker valve is fluidly connected to a control fluid outlet of the spool valve. An electrical module is operatively connected to the pilot valve, a supply of control fluid, and the blocker valve, the electrical module being capable of sending pulsed electrical signals to the pilot valve and the blocker valve to selectively position the spool valve and the blocker valve to an open or closed position.

Hydraulic systems and associated methods configured to reduce leakage past a spool valve when the system is in a neutral state. Leakage reduction is achieved by shifting the spool valve within the spool bore. The amount of shifting can be controlled by a pressure controller that sets one or pressures in the system and actively/dynamically adjusts the system to achieve a desired pressure or set of pressures by shifting the spool valve.

In a valve device, travel control valve unit has a communication path causing the lead-out passages of the left and right travel control valve units to communicate with each other, and a spool has a lead-out side land portion configured to cause communication or shut-off of the communication between the lead-out passage and the communication path, a discharge-side land portion configured to cause communication or shut-off of the communication between the actuator passage and the discharge passage, a discharge portion configured to discharge a part of the working fluid led from the supply passage to the lead-out passage to the discharge passage at a movement initial stage of the spool, and a communication portion configured to cause the lead-out passage and the communication path to communicate with each other at a movement final stage of the spool.

The device includes a main valve, first and second auxiliary valves, a valve body and a filter. The main, which has first and second auxiliary valves are mounted on the valve body, which has an air inlet, a cylinder port and an air discharging port. The air inlet is in communication with the main valve through a first air passage, the cylinder port is sequentially in communication with the first and second auxiliary valves, and the main valve through a second air passage. The air discharging port is sequentially in communication with the first and second auxiliary valves and the main valve through a third air passage. The main and the second auxiliary valves are solenoid valves, and the first auxiliary valve is a hand-operated valve. An air outlet of the filter is in communication with the air inlet. The filter is used for filtering out impurities in gas.

A solenoid device includes a yoke, a core, a shaft, a bobbin, a coil, a plunger, a lid, and a housing. A housing body part of the housing has a first opening; a cylindrical first inner wall part having a first step part extending toward the outer side in the radial direction; and a cylindrical second inner wall part having a second step part extending toward the outer side in the radial direction. A first cylindrical part has a first flange part. The outer diameter of the first flange part is larger than the inner diameter of the first inner wall part and smaller than the inner diameter of the second inner wall part. A circumferential end part of the first flange part contacts the second step part. The lid is non-magnetic, and a circumferential edge part is held between the first step part and the first flange part.

The present disclosure provides a high flow coefficient spool valve (50) through one or more changes in the flow path from a conventional spool valve. The body (56) of the spool valve includes spherically contoured internal grooves (68). The spool (58), slidably engaged inside the body (56), includes concave surfaces between seals (62) that is complementary to the spherically shaped internal grooves (68) of the body. The spherical shape of the body internal grooves (68) and/or concave shape of the spool allow more volume and more laminar flow therebetween, resulting in an increased flow coefficient and flow capacity. The body also is formed with transverse port windows in the port that contour into a bore of the body adjacent the spool. A choke volume in the flow is strategically designed in a parallel flow location rather than a perpendicular flow location to promote laminar flow and lessen turbulence to also increase the flow coefficient.

A fluid valve includes a valve member located between a first cavity and a second cavity, and an actuator that includes a pilot. The valve member is moved by the balance between the pressure prevailing in the first cavity and the pressure prevailing in the second cavity. The valve member includes a longitudinal hole that can be blocked by the pilot so as to modify the pressure prevailing in the first cavity and the force acting on the valve member so as to vary a fluid flow rate between an inlet and two outlets. The valve member is attached to a piston, one end of which is located in a third cavity. The force acting on the valve member is determined by the pressures prevailing in the various cavities.

A slide for a fuel circuit valve of an aircraft engine extending along a longitudinal axis, and comprising a narrowed intermediate portion extending between two cylindrical end portions, a first end portion being separated from the narrowed intermediate portion by a shoulder having a surface arranged overall perpendicular to the longitudinal axis, the narrowed intermediate portion including in turn, as an extension of the shoulder, at least one cylindrical portion, the shoulder comprising at least one groove which extends radially from the cylindrical surface of the first end portion, towards the longitudinal axis, and which forms a fuel recirculation area which provides the generation of a jet of fuel on the cylindrical portion of the narrowed intermediate portion, when fuel flows along the first end portion towards the narrowed intermediate portion and the second end portion.

A pressure regulator includes a cylinder and a piston contained in the cylinder. First and second O-rings are attached to the cylinder and configured to form a seal between the cylinder and an interior wall of the piston. The pressure regulator has a lubrication system that includes a lubrication reservoir between the first and second O-rings defined by an annular groove in an exterior surface of the piston and the interior wall of the cylinder, and an input port extending through the cylinder to the lubrication reservoir. The piston is configured to move along a central axis relative to the cylinder between first and second positions. The first and second O-rings are displaced from the input port during movement of the piston between the first and second positions.

An emergency shut-off device shuts off supply of control oil to a trip-and-throttle valve of a steam turbine and closes the trip-and-throttle valve in an emergency. The emergency shut-off device includes: a cylinder; a piston that slides into the cylinder; a spring that applies a biasing force to the piston; a plurality of piston valves disposed on the piston; and a plurality of chambers that are formed by the piston valves. The control oil is supplied to and drained from the plurality of chambers, and a sliding surface of each of the piston valves has a groove to leak the control oil in a corresponding one of the chambers to another one of the chambers that is adjacent to the corresponding chamber in an axis direction.