A hydraulic system for a rapid mooring device of an offshore operation helicopter includes a fuel tank, a hydraulic pump, an electric motor, a check valve, a pressure sensor, a filter, an overflow valve, a two-position four-way electromagnetic reversing valve group, a three-position four-way Y type hydraulically operated reversing valve, an stacked double throttle check valve, an stacked internally controlled hydraulic lock, an externally controlled large flow hydraulic lock, a safety valve, a cartridge valve, an energy accumulator, a pneumatic hydraulic pump, a thick and thin parallel single rod hydraulic cylinder, a mechanical claw unlocking cylinder, a centering lock unlocking cylinder and an emergency lock unlocking cylinder. The control method includes routine action control methods such as rapid capture, straightening, rapid release, transverse mechanical locking, and transverse hydraulic locking in a traction process of the helicopter, a safety protection control method, and an emergency action control method.

A method is proposed for establishing termination criteria for a partial stroke test on a safety valve, including: a) A partial stroke test is carried out when the safety valve is operational. b) Position of the valve member and pressure in the drive fluid are recorded. c) A first relation is derived, which relates position of the valve member, time, pressure of the drive fluid, and/or control deviation to one another. d) This relation is defined as a safety valve reference curve. e) A second relation is defined, which has a predetermined distance from the reference curve. f) Termination criterion include: If the partial stroke test is repeated on the same valve, the same data are recorded and a third relation is derived for the reference curve, the partial stroke test is not passed if the third relation has a greater distance to the reference curve than the second relation.

A hydraulic system for a rapid mooring device of an offshore operation helicopter includes a fuel tank, a hydraulic pump, an electric motor, a check valve, a pressure sensor, a filter, an overflow valve, a two-position four-way electromagnetic reversing valve group, a three-position four-way Y type hydraulically operated reversing valve, an stacked double throttle check valve, an stacked internally controlled hydraulic lock, an externally controlled large flow hydraulic lock, a safety valve, a cartridge valve, an energy accumulator, a pneumatic hydraulic pump, a thick and thin parallel single rod hydraulic cylinder, a mechanical claw unlocking cylinder, a centering lock unlocking cylinder and an emergency lock unlocking cylinder. The control method includes routine action control methods such as rapid capture, straightening, rapid release, transverse mechanical locking, and transverse hydraulic locking in a traction process of the helicopter, a safety protection control method, and an emergency action control method.

A control system includes a pneumatic actuator having a spring that is compressible by a gas and connected to the isolation valve, wherein the gas is supplied to the pneumatic actuator along a gas flow path, a solenoid valve operable between an open position and a closed position, wherein the open position permits the gas to flow along the gas flow path to the pneumatic actuator, a partial stroke test device configured to perform partial stroking of the isolation valve upon reception of a signal from a computer by sending the gas to the pneumatic actuator through a needle valve, and a universal operation hand operated valve configured to send the gas to the solenoid valve or to the partial stroke test device.

An emergency shut-off valve and means for initiating a test on said emergency shut-off valve includes a source of pressurized gas, a main solenoid responsive to a signal from said means for initiating a test and a source of pressurized gas are included. Further, means including a main solenoid responsive to a signal from said means for initiating a test and a main solenoid valve and a quick exhaust valve connected to the source of pressurized gas. Further, a pneumatic actuator for opening and closing the shut-off valve and test means for testing the emergency shut-off valve without fully closing the emergency shut-off valve in response to a signal from the means for initiating a test. The test means includes a second solenoid.

A hydraulic system (600) and method for reducing boom dynamics of a boom (30), while providing counter-balance valve protection, includes a hydraulic actuator (110), first and second counter-balance valves (300, 400), first and second independent control valves (700, 800), and first and second blocking valves (350, 450). The actuator includes first and second corresponding chambers. In a first mode, the second counter-balance valve is opened by the first control valve, and the first counter-balance valve is opened by the second control valve. In a second mode, at least one of the counter-balance valves is closed. A meter-out control valve (800, 700) may be operated in a flow control mode, and/or a meter-in control valve (700, 800) may be operated in a pressure control mode. Boom dynamics reduction may occur while the boom is in motion (e.g., about a worksite). By opening the counter-balance valves, sensors at the control valves may be used to characterize external loads. The control valves may respond to the external loads and at least partially cancel unwanted boom dynamics. The system may further detecting faults in actuators with counter-balance valves and prevent any single point fault from causing a boom falling event and/or mitigate such faults.

An emergency shut-off valve and means for initiating a test on said emergency shut-off valve includes a source of pressurized gas, a main solenoid responsive to a signal from said means for initiating a test and a source of pressurized gas are included. Further, means including a main solenoid responsive to a signal from said means for initiating a test and a main solenoid valve and a quick exhaust valve connected to the source of pressurized gas. Further, a pneumatic actuator for opening and closing the shut-off valve and test means for testing the emergency shut-off valve without fully closing the emergency shut-off valve in response to a signal from the means for initiating a test. The test means includes a second solenoid.

A system for monitoring performance of a relief valve in a hydraulic system having a hydraulic actuator includes a supply discharge line fluidly coupled between a source of pressurized fluid and a fluid chamber of the actuator. The supply discharge line has a supply valve disposed therein. The system also includes a main relief line and a line relief line fluidly coupled to the supply discharge line. The main relief line includes a main relief valve and is disposed upstream of the supply valve while the line relief line includes a line relief valve and is disposed downstream of the supply valve. The line relief valve is configured to open at a pressure value greater than that used in the main relief valve. A controller compares fluid pressures in the main relief line and the line relief line to determine if the line relief valve is leaking.

A hydraulic system is disclosed for use with. a machine. The hydraulic system may have an actuator, a valve associated with the actuator, at least one sensor configured to generate signals indicative of performance parameters of the hydraulic system, and a controller. The controller may be configured to determine at least one of a diagnostic movement and position of at least one of the fluid actuator and valve required to perform a health cheek, and to correlate the signals generated only during completion of the diagnostic movement or only when the at least one of the fluid actuator and valve are in the diagnostic position to values of the performance parameters. The controller may also be configured to make a comparison of the values of the performance parameters to expected values, and to determine a health of the hydraulic system based on the comparison.

A method for automatically testing a hydraulic system of an aircraft during ground service is disclosed. The hydraulic system includes, onboard of the aircraft, a hydraulic pump, a hydraulic reservoir, a hydraulic conduct system, a hydraulically driven unit, and a control and monitoring unit, the method includes the steps a) pressurizing the hydraulic system by the hydraulic pump, b) monitoring at least one parameter indicative of an external leakage of the hydraulic system during the pressurisation of the hydraulic system, c) determining whether an external leakage of the hydraulic system exists on basis of the at least one parameter.