A piston type hydro pneumatic accumulator with internal leak detection, having a gas chamber and a liquid chamber, the piston type hydro pneumatic accumulator comprising a cylindrical barrel, a floating piston, a gas end cover, a liquid end cover, a leakage detection construction having a first cylindrical channel reducing to a conical channel and further reducing to a second cylindrical channel, a floater device, the gas end cover and the liquid end cover hermetically disposed into the cylindrical barrel, a first pressure meter disposed so as to measure a pressure in the first cylindrical channel and a second pressure meter disposed so as to measure the pressure in the second cylindrical channel, the readings in the two pressure meters used for inferring a gas leakage or a liquid leakage. Also deployable a first pressure switch sensing a pressure P1 and a second pressure switch sensing a pressure P2, the output of the first pressure switch and the second pressure switch connected to a programmable logic controller, programmed so as to activate a liquid circuit for topping up of the liquid if P1>P2, activate a gas circuit for re-charging of gas if P1=P20, produce a visual and or an audio signal or a combination thereof, or initiate any other corrective action.

A pressure accumulator includes an accumulator housing (2) in which a movable separating element (30) fluid-tightly separates a gas chamber (16) filled with a working gas from a fluid chamber (28). A monitoring device (50, 54) supplies an optical signal in the event of a malfunction affecting the sealing effect of the separating element (30).

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 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.

A hydraulic circuit is pressurized by a hydraulic pump driven by a power source in a machine. The hydraulic circuit is configured to use pressurized fluid from an accumulator to drive a hydraulic accessory when the hydraulic pump is inactive and the power source is shut down for fuel savings during idle operations. A valve may be configured to selectively supply pressurized hydraulic fluid to the accessory when the pump is inactive.

A hydraulic pumping method for use with a subterranean well can include mounting a hydraulic actuator above a wellhead, the hydraulic actuator and the wellhead being axially aligned with each other and inclined relative to vertical The hydraulic actuator can be unsupported by any substructure or guy wires after the mounting. A hydraulic pumping system for use with a subterranean well can include a hydraulic actuator including a piston that displaces in response to pressure in the actuator, a magnet that displaces with the piston, and a magnetic field sensor that detects a presence of the magnet. The hydraulic actuator may be mounted above a wellhead, with the hydraulic actuator and the wellhead being axially aligned with each other and inclined relative to vertical.

A hydraulic pumping system can include a hydraulic actuator with a magnet that displaces with a piston, and a sensor that continuously detects a position of the magnet. A ferromagnetic wall of the hydraulic actuator is positioned between the magnet and the sensor. A hydraulic pumping method can include incrementally lowering a lower stroke extent of a rod string reciprocation over multiple reciprocation cycles of the rod string, and automatically varying the lower stroke extent or an upper stroke extent of the rod string reciprocation, in response to a measured vibration. Another hydraulic pumping method can include solving a wave equation in the rod string, and automatically varying a reciprocation speed of the rod string in response to a change in work performed during reciprocation cycles of the hydraulic actuator or a change in detected force versus displacement in different reciprocation cycles of the hydraulic actuator.

A pumping method can include displacing a rod string with pressure applied to an actuator by a pressure source including an accumulator and a separate gas volume in communication with the accumulator. A sensor indicates whether a fluid is in the gas volume. A pumping system can include an actuator, a pump connected between the actuator and an accumulator, a hydraulic fluid contacting a gas in the accumulator, a separate gas volume in communication with the accumulator, and a sensor that detects the hydraulic fluid in the gas volume. Another pumping system can include an actuator, a pump connected between the actuator and an accumulator that receives nitrogen gas from a nitrogen concentrator assembly while a hydraulic fluid flows between the pump and the actuator, a separate gas volume in communication with the accumulator, and a sensor that detects a presence of the hydraulic fluid in the gas volume.

A hydraulic pumping system can include an actuator including a piston rod that displaces in response to pressure in the actuator, a seal assembly that seals about the piston rod and is exposed to the pressure in the actuator, and another seal assembly that seals about the piston rod, is exposed to pressure in a well and includes multiple separate seal cartridges, each of the seal cartridges including a dynamic seal that slidingly and sealingly engages the piston rod. Another hydraulic pumping system can include an actuator including a piston rod that displaces in response to pressure in the actuator, a seal assembly that seals about the piston rod and is exposed to the pressure in the actuator, and another seal assembly that seals about the piston rod, is exposed to pressure in a well and includes a labyrinth ring comprising multiple ring layers.

Pressure accumulator with an accumulator housing (10), in which a movable separating element (16) separates a medium space (12), preferably filled with a working gas, from a fluid space (14) in a fluid-tight manner, wherein a monitoring device (28) is provided and gives a visually perceptible indication when there is a fault that impairs the sealing effect of the separating element (16), the monitoring device having a viewing window through which it is possible to observe an indicator which is in connection with the medium space (12) and the optical property of which perceptibly changes when it is wetted with the fluid, characterized in that the monitoring device (28) has a screw plug, which can be screwed with its external thread into an assigned internal thread of the accumulator housing (10) and which has the viewing window and the indicator and also a fluid-permeable shutting-off device, which forms in the screw plug a receiving space partly delimited by the viewing window and intended for receiving the indicator, the shutting-off device spatially separating the receiving space from the interior of the medium space (12) of the accumulator housing (10).