An accumulator system includes a chamber configured to receive a first fluid, a piston configured to move within the chamber to pressurize and drive the first fluid out of the chamber, a driving shaft coupled to the piston, a screw adapter coupled to the driving shaft, a plurality of anti-rotation shafts, and an electric actuator configured to couple to the screw adapter and to rotate the screw adapter to axially move the driving shaft. The piston includes a body defining a first aperture and a plurality of counterbores. The driving shaft is coupled to the piston via the first aperture. The piston is configured to slide over the plurality of anti-rotation shafts via the plurality of counterbores.

An apparatus (1) for damping pressure pulsations, includes: a working chamber (5) to which a working pressure (p.sub.1) is or can be applied; and a compensation chamber (6) which is separated from the working chamber (5) by an at least partially elastic separating diaphragm (4). The apparatus (1) is distinguished in that working chamber (5) and compensation chamber (6) are connected to one another in a fluid-conducting manner via at least one line device (7).

A double acting accumulator system includes a housing including an actuator housing, a first piston housing coupled to the actuator housing, a second piston housing coupled to the actuator housing, a shaft configured to move axially within the first piston housing and the second piston housing, a first piston coupled to a first end of the shaft, a second piston coupled to a second end of the shaft, an electric actuator configured to couple to and drive the shaft to alternatingly compress fluid with the first piston in the first piston housing and the second piston in the second piston housing to drive fluid out of the respective first piston housing and the second piston housing, and a plurality of anti-rotation shafts configured to block rotation of the shaft.

A hydraulic system for use during reduced gravity flight including: (1) a reservoir; (2) a hydraulic device; (3) a supply line providing fluid communication between the reservoir and the hydraulic device; (4) a return line providing fluid communication between the hydraulic device and the reservoir; (5) a supply valve located on the supply line between the reservoir and the hydraulic device and selectively configurable in an open or closed position; and (6) a return valve located on the return line between the reservoir and the hydraulic device and selectively configurable in an open or closed position; and (7) wherein the supply valve is adapted to prevent fluid communication between the reservoir and the hydraulic device when in the supply valve closed position; and (8) wherein the return valve is adapted to prevent fluid communication between the reservoir and the hydraulic device when in the return valve closed position.

The publication relates to a depth compensated actuator, for a transportable inline depth compensated heave com-pensator for subsea lifting operations. The actuator comprises a cylinder shaped body and a piston with a piston rod, the piston rod being intended for exposure to external water pressure, a first and second connection means associated with the actuator. Further, the actuator comprises a depth compensator comprising a cylinder, a piston and a piston rod, the end of which being exposed to surrounding water; and conduit means between at least one volume in the actuator and one volume in the depth compensator. The pistons and piston rods are shaped as any of: hollow piston rod, ring shaped piston, ring piston rod. The depth compensated actuator solves the problem if improving depth compensation performance regarding size, weight, required fluid consumption, internal/inherent friction and adaptability. Further, use of a depth compensated actuator is claimed.

Hydraulic pressure compensator units and hydraulic systems incorporating hydraulic pressure compensator units. The pressure compensator units include a main valve body defining a central axis and a first central passage, a compensation valve member positioned in the first central passage and defining a second central passage, the first central passage being in selective fluid communication with a port of hydraulic actuator. A load sense check component is positioned within the second central passage and adapted to move in a first axial direction to selectively open a fluid communication between a pump output and a load sense line. A reverse flow check component is positioned within the second central passage and adapted to move in a second axial direction opposite the first axial direction to selectively open a fluid communication between the hydraulic actuator and a tank line.

A milking robot for the fully automatic milking of dairy animals includes at least one moving component and a cylinder configured to support a movement of the component. The cylinder has a cylinder wall having an aeration opening, as well as a cylinder rod slidable into and out of the cylinder. The cylinder wall surrounds at least one variable volume part, which volume part is free from pressure fluid connections for displacement of the cylinder rod. The cylinder is configured to remain, via the opening, substantially in pressure equilibrium with an environment of the cylinder. To the cylinder wall around the aeration opening is connected a gas collecting device which has a changeable volume and which, together with the variable volume part, forms an airtight gas volume. In addition, the gas collecting device has a minimum volume greater than zero.

Embodiments of the present disclosure describe both mechanically-operated and electrically-operated, locally-actuated partial stroke testing devices and systems for testing operation of an emergency isolation valve.

A self-contained expandable automatic pressure compensated accumulator system for storing and releasing hydraulic fluid energy for use by subsea equipment having a controller, a pressure source, a bidirectional valve fluidly connected to the pressure source, an expandable multisided vessel fluidly connected to the bidirectional valve having a plurality of axial folds between first and second ends, and a bidirectional port connected to the pressure source. As the plurality of axial folds expand, a contracted volume of pressure expands increasing stored hydraulic fluid energy in the expandable multisided vessel. As the plurality of axial folds contract, the expanded volume reduces, releasing stored hydraulic fluid energy to nearby subsea equipment on demand as changes in hydraulic fluid energy requirements for the subsea equipment changes. Simultaneously, hydrostatic seawater pressure of seawater on the expandable multisided vessel is counteracted with the hydrostatic pressure of fluid inside the expandable multisided vessel.

A subsea arrangement including a main enclosure having a main enclosure volume; at least one main pressure compensator having a variable compensation volume in fluid communication with the main enclosure volume and configured to compensate volume variations of an internal fluid in the main enclosure volume; and at least one pressure sensor arranged to measure a pressure of the internal fluid. A method for detecting a malfunction of a subsea arrangement including a main enclosure having a main enclosure volume and at least one main pressure compensator is also provided.