A hydraulic system includes: a high-pressure line; a pump configured to supply pressurized hydraulic fluid to the high-pressure line; a variable displacement hydraulic machine connected by a fluid connection to the high-pressure line for rotationally driving the rotatable load; an electronic control unit; an energy storing device connected to the high-pressure line and configured to communicate with the high-pressure line by receiving energy from the high-pressure line and/or supplying energy to the high-pressure line; and a first detector configured to detect the amount of energy stored in the energy storing device and to transmit a signal indicating said amount of energy stored to the electronic control unit. The electronic control unit is configured to control the volume flow intake of the variable displacement hydraulic machine dependent on a target output of the variable displacement hydraulic machine and on the detected amount of energy stored in the energy storing device.

A control system may receive sensor data indicative of respective fluid levels of two or more hydraulic accumulators configured to operate at respective target fluid levels within a hydraulic system. The control system may determine respective errors of the hydraulic accumulators based on the respective fluid levels and respective target fluid levels of the hydraulic accumulators. The respective errors may correspond to pressure errors, fluid volume errors, or other types of errors of the hydraulic accumulators. Responsive to determining the respective errors, the control system may determine that the error of a given hydraulic accumulator is greater than errors of the other hydraulic accumulators and provide instructions to control a hydraulic valve to supply fluid from a single pump of the hydraulic system to the given hydraulic accumulator

A pressure vessel arrangement includes a pressure vessel and an optical sensor arrangement. The pressure vessel includes: a cylinder construction having a cylinder wall extending from a cylinder wall first end to a cylinder wall second end, and having an internal surface forming an interior region; a first end cap closing the cylinder wall first end and having an optical window located therein to permit passage of light therethough and into the interior region; a second end cap closing the cylinder wall second end; and a piston constructed to slide within the cylinder construction interior region along a direction between the cylinder all first end and the cylinder wall second end and along the cylinder construction internal surface to separate the interior region into a first end interior region and a second end interior region. The pressure vessel is constructed to withstand a fatigue test of one million cycles at 5,000 psi without failure. The optical sensor arrangement is located outside of the optical window and includes an emitter for emitting light through the optical window and into the interior region and receiving for receiving light reflected from the piston. Also included is a method for providing a piston position feedback in a pressure vessel.

A control system may receive sensor data indicative of respective fluid levels of two or more hydraulic accumulators configured to operate at respective target fluid levels within a hydraulic system. The control system may determine respective errors of the hydraulic accumulators based on the respective fluid levels and respective target fluid levels of the hydraulic accumulators. The respective errors may correspond to pressure errors, fluid volume errors, or other types of errors of the hydraulic accumulators. Responsive to determining the respective errors, the control system may determine that the error of a given hydraulic accumulator is greater than errors of the other hydraulic accumulators and provide instructions to control a hydraulic valve to supply fluid from a single pump of the hydraulic system to the given hydraulic accumulator.

A method includes detecting at least one position measurement of a separator piston of a pitch trim actuator. The method includes detecting at least one pressure measurement of an oil. The method includes detecting at least one temperature measurement of the oil. The method includes storing at least one position value based on the at least one position measurement of the separator piston, at least one pressure value based on the at least one pressure measurement of the oil and at least one temperature value based on the at least one temperature measurement of the oil. The method includes determining whether the pitch trim actuator requires servicing based on the at least one position value, the at least one pressure value, and the at least one temperature value.

A system for determining the location of a piston within an accumulator is provided in which a short circuit is created between elements in the accumulator and the piston which is movable within the accumulator. As the piston moves along the longitudinal axis of the accumulator, the circuit's electrical characteristics (e.g., voltage, resistance, current) vary in accordance with the length of the circuit. Measurement of these electrical characteristics allows for precise determination of the piston location relative to the accumulator. In a commercial embodiment, the invention can be utilized to determine fluid volumes in an accumulator by monitoring the location of the piston. This invention overcomes prior art systems because, inter alia, it does not require electrical sensory equipment, enables remote monitoring, maintains system integrity and functions irrespective of container wall thickness.

A method includes detecting at least one position measurement of a separator piston of a pitch trim actuator. The method includes detecting at least one pressure measurement of a gas. The method includes detecting at least one temperature measurement of the gas. The method includes storing at least one position value based on the at least one position measurement of the separator piston, at least one pressure value based on the at least one pressure measurement of the gas and at least one temperature value based on the at least one temperature measurement of the gas. The method includes determining a volume of an oil within an oil chamber of the pitch trim actuator and a pressure of the gas within the gas chamber of the pitch trim actuator, based on the at least one position value, the at least one pressure value and the at least one temperature value.

A fluid management system includes a hydraulic main pump fluidly connected to a load, an accumulator fluidly connected to the hydraulic main pump, a secondary pump, a fluid preparation system fluidly connected between an outlet of the secondary pump and an inlet of the hydraulic main pump, a reservoir, and a valve system fluidly connecting the reservoir, an outlet of the hydraulic main pump, and the secondary pump inlet. The system is at least operable between a run mode, wherein the secondary pump and accumulator cooperatively maintain the pressure within the hydraulic main pump, and a charging mode, wherein the secondary pump pumps fluid into the accumulator until a threshold volume is reached.

A pressure compensation system is provided. A subsea enclosure of the subsea device encloses the chamber. A first pressure compensator has a first compensation volume and provides pressure balancing between ambient medium surrounding the subsea device and the first compensation volume. A first biasing device is configured to bias the first pressure compensator such that the pressure in the first compensation volume is higher than the pressure in the ambient medium surrounding the subsea device. A second pressure compensator has a second compensation volume and provides pressure balancing between the ambient medium and the second compensation volume. A second biasing device biases the second pressure compensator such that the pressure in the second compensation volume is higher than the pressure in the ambient medium. A control unit is connected to control first and second valves arranged in flow connections between the first and second compensation volumes and the chamber.

A method and system providing a pressurized fluid includes a pump having a pump inlet and a pump outlet, the pump to provide a fluid flow, a bypass path to direct the fluid flow from the pump outlet to the pump inlet, a load path having a load path pressure, the load path including: a fluid accumulator to accumulate a fluid volume, and at least one load device, a bypass regulator valve in fluid communication with the pump outlet, the bypass path, and the load path, and a controller to direct the fluid flow to the load path in response to the load path pressure being less than a low load path threshold pressure via the bypass regulator valve and to direct the fluid flow to the bypass path in response to the load path pressure being greater than a high load path threshold pressure via the bypass regulator valve.