A solenoid valve assembly has a valve body in which a spool is slidably mounted and operated by a solenoid having a coil. A manifold member has a plurality of flow paths for supplying and discharging pressurized fluid to and from ports of the solenoid valve assembly. An intermediate block is interposed between the valve body and the manifold member. The intermediate block has a plurality of through holes for connecting ports of the manifold member to ports on the valve body. At least one sensor is housed in the intermediate block for sensing at least one of pressure and flow in at least one of the through holes.

A method is provided for detecting and quantifying leaks in a gas network under pressure or vacuum. The gas network includes one or more sources of compressed gas or vacuum; one or more consumers or consumer areas of compressed gas or vacuum applications; pipelines or a network of pipelines to transport the gas or vacuum; a plurality of sensors which determine one or a plurality of physical parameters of the gas in the gas network. The gas network has controllable or adjustable relief valves and the method involves a training phase and an operational phase.

A fluid leakage detection device includes: an annular member attached to a cylinder head, the annular member being configured such that a piston rod is inserted through the annular member; a passage formed in the annular member, the passage being configured such that a working fluid is guided to the passage from a gap between an outer circumference of the piston rod and an inner circumference of the cylinder head; and a detector configured to detect the working fluid guided through the passage, wherein the annular member includes a press-fitted portion, the press-fitted portion being configured to be press-fitted to an annular groove formed in the cylinder head.

[Solution] A pilot check valve includes a first body that has input and output ports, a main path 13 that is in communication these ports, and a check valve element that allows a flow of a pressure fluid from the input port toward the output port. The valve element blocks or allows a flow toward the input port side by supply or discharge of a pilot fluid and has a residual pressure exhaust path connected between the main path and an exhaust hole, a seal member that is provided in the exhaust path, and a push rod that moves the check valve element to a position where a flow of a pressure fluid toward the input port side in the main path is allowed and moves the seal member to a position where a flow toward the exhaust hole is allowed.

A system for oil leak mitigation in hydraulic systems. The systems and methods prevent or mitigate oil leakage from hydraulic components. In one embodiment, a flexible bellows is provided positioned over a hydraulic rod to collect leaking oil. The bellows is connected to the hydraulic actuator by means of at least one magnet, in one embodiment. In another embodiment, a sleeve is connected to the actuator to collect oil droplets. The sleeve is connected to the actuator by means of a 4-bolt flange (in some embodiments).

A method for selectively coupling or uncoupling a coupling with a release, arranged between the supply conduit and a cylinder, on the basis of pressure in a supply conduit. The method includes providing an operating pressure prevailing in the supply conduit in order to provide hydraulic liquid to the cylinder on the basis thereof and providing an uncoupling pressure prevailing in the supply conduit for the purpose of activating shut-off valves in the supply conduit and on the cylinder and activating a release which uncouples the coupling. A coupling for respectively coupling and uncoupling a supply conduit which is connected to the coupling to/from a cylinder, as well as to an assembly including a pump, a cylinder, a supply conduit between the pump and the cylinder, and such a coupling.

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.

There is provided a construction machine that is capable of measuring a minute leakage flow rate of a one-sided tilting variable displacement hydraulic pump. The construction machine includes a pressure sensor that detects a pressure of a hydraulic pump, a bleed-off adjusting device that is enabled to adjust a bleed-off flow rate of the hydraulic pump, and an input device that gives an instruction for measurement of a leakage flow rate of the hydraulic pump. The controller is configured to measure, when the controller determines that the operation device is in a non-operated state and when a measuring command is inputted from the input device, a pressure of the hydraulic pump while changing a control command value for the bleed-off adjusting device in a state in which a flow rate of the hydraulic pump is maintained, and calculate the leakage flow rate of the hydraulic pump on the basis of the control command value for the bleed-off adjusting device at the time that the pressure of the hydraulic pump is stabilized at a predetermined pressure.

A refuse collection vehicle has various hydraulic actuators including at least one cylinder with an internal seal. A sensor is responsive to movement of the piston and sends a signal to a controller to indicate piston movement information during an associated vehicle body component movement. The controller is configured to determine a motion characteristic of the piston during a predetermined body component movement, compare the determined motion characteristic to a stored reference motion characteristic, and in response to determining that a difference between the determined motion characteristic and the reference motion characteristic is greater than a predetermined value, trigger an indication that the refuse collection vehicle is in need of service.

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.