The invention relates to a hydraulic cylinder, for example for use with a hydraulic tool, which hydraulic tool is provided with a frame and an element which is movable with respect to the frame by means of the hydraulic cylinder. A hydraulic tool which is operated by means of a hydraulic cylinder as described above is known from, for example, European patent no. 0641618. This patent discloses a frame which is coupleable to a jib of an excavator or the like and to which an assembly of two jaws can be coupled. One of the jaws is pivotable with respect to the other jaw by means of a hydraulic adjusting cylinder (a double-acting piston/cylinder combination).

The present invention relates to a device for detecting leaks in a hydraulic cylinder, comprising: a first pressure sensor for detecting a pressure value in a first pressure chamber of a hydraulic cylinder, a second pressure sensor for detecting a pressure value in a second pressure chamber of the hydraulic cylinder, an evaluation unit for continuously detecting the pressure values of the first pressure sensor and the second pressure sensor, the evaluation unit being designed to detect a leak, preferably an internal leak, in the hydraulic cylinder that deviates from the norm based on the pressure values recorded by the first pressure sensor and the second pressure sensor.

A petroleum pipeline safety system for preventing contamination of an environmentally sensitive area close to a pipeline is provided. The system includes a first portion of the pipeline including an upstream portion of the pipeline supplying a flow of fluid material and a flow restriction downstream of the first portion of the pipeline. The system further includes a second portion of the pipeline downstream of the flow restriction, receiving the flow of fluid material from the first portion and conveying the flow of fluid material through the environmentally sensitive area to a downstream portion of the pipeline. The flow restriction is configured to create a lower pipeline internal pressure within the second portion as compared to a pipeline internal pressure within the first portion. The system further includes a third portion of the pipeline downstream of the environmentally sensitive area and including the downstream portion of the pipeline.

Provided is an arrangement and a method to detect an oil leakage between a first section and a second section of a hydraulic cylinder. A movable piston is arranged between the first and second section in a way that the piston changes position between the sections. The change in position is done in dependency of a difference between a first force, which acts at the first section on a first cross sectional area of the piston, and a second force, which acts at the second section on a second cross sectional area of the piston. The first section comprises hydraulic oil with a predefined first pressure, while the first force is calculated based on this pressure and based on the first area. The second section comprises hydraulic oil with a predefined second pressure, while the second force is calculated based on this pressure and based on the second area.

A piston accumulator has an accumulator housing and a separating piston (8) guided for longitudinal motion in the accumulator housing. The separating piston separates a liquid side (4) from a gas side (10) in the accumulator housing. Liquid unintentionally transitions from the liquid side (4) to the gas side (10) despite a piston seal on the separating piston (8). By a return device (28), the transitioned liquid is at least partially returned from the gas side (10) of the accumulator housing to the liquid side (4) of the accumulator housing.

An aircraft pneumatic system including a pneumatic actuator arranged to operate at a pressure value at least equal to a pressure threshold, a line fluidly connected between a pneumatic source and the pneumatic actuator, and a venturi disposed upstream of the line and downstream of the pneumatic source. The venturi is configured to receive a source flow from the source at a mass flow rate, the mass flow rate being between a lower, nominal flow rate value and a higher, graded flow rate value. The venturi is sized such that when the mass flow rate is at the nominal flow rate value, a line pressure inside the line corresponds to a source pressure upstream of the venturi, and when the mass flow rate to the venturi is at the graded flow rate value, the line pressure is less than the source pressure.

A system for controlling a hydraulic component. The system includes a control system configured to carry out a health check routine having steps of (A) fluidly connecting one of the hydraulic supply systems with the component until (i) a predetermined pressure is reached on the hydraulic supply side and/or the hydraulic return side, and/or (ii) a predetermined amount of time has passed; then (B) isolating the pressurised hydraulic fluid within the hydraulic supply side and the hydraulic return side so that hydraulic fluid leaks from the hydraulic supply side to the hydraulic return side via the controlled leakage; (C) monitoring the pressure of hydraulic fluid within the hydraulic supply side (50S) and/or the hydraulic return side over time; and then (D) determining if the pressure of hydraulic fluid within the hydraulic supply side and/or the hydraulic return side follows a predetermined or expected pattern.

A system may include a hose assembly; a sensor device; and a controller. The hose assembly may be configured to be connected to a hydraulic circuit of a machine. A first layer, of a hose of the hose assembly, may be configured to transport a hydraulic fluid. A second layer, of the hose, may comprise a tracer material that is configured to be released into the hydraulic fluid when the first layer is experiencing a failure. The sensor device may be configured to detect the tracer material in the hydraulic fluid, and generate sensor data indicating that the tracer material has been detected. The controller may be configured to determine that the hose assembly is experiencing the failure based on the sensor data and cause an action to be performed based on determining that the hose assembly is experiencing the failure.

A fluid leakage detection device includes: a rod seal provided in a cylinder head, a rod seal being configured to seal an annular gap between a piston rod and the cylinder head; a detection seal configured to seal an annular gap, a detection seal being configured to partition the detection space together with the rod seal; a communication passage in communication with the detection space; a pressure sensor configured to detect the pressure of the working oil guided through the communication passage; and a relief valve configured to release the pressure in the communication passage, wherein the detection seal is provided between the rod seal and a dust seal, the dust seal being configured to seal the annular gap by being provided in the cylinder head so as to face the outside of the cylinder tube.

A piston accumulator has an accumulator housing and a separating piston (8) guided for longitudinal motion in the accumulator housing. The separating piston separates a liquid side (4) from a gas side (10) in the accumulator housing. Liquid unintentionally transitions from the liquid side (4) to the gas side (10) despite a piston seal on the separating piston (8). By a return device (28), the transitioned liquid is at least partially returned from the gas side (10) of the accumulator housing to the liquid side (4) of the accumulator housing.