A method is provided for determining a gas charge pressure P.sub.calcGC of a hydraulic accumulator within a hydraulic fluid system. The method includes receiving pressure decay data representing the pressure decay within a self-pressurizing hydraulic reservoir of the hydraulic fluid system as the self-pressurizing hydraulic reservoir depressurizes from an operating pressure of the self-pressurizing hydraulic reservoir towards atmospheric pressure. The method also includes calculating the gas charge pressure P.sub.calcGC of the hydraulic accumulator using the received pressure decay data of the self-pressurizing hydraulic reservoir.

A system and method of predicting impending failure of a pressure vessel include a pressure vessel, a fluid source, a line coupled to the pressure vessel and to the fluid source, an apparatus, a sensor and a controller. The apparatus includes a conduit and a containment structure. The containment structure includes a cavity separated from an interior of the conduit by a portion of a conduit wall of the conduit. The sensor is configured to determine a value of a physical property in the cavity. The controller is in signal communication with the sensor and configured to detect a change in the value. The method includes determining a first value of a physical property in the cavity, experiencing a failure of the conduit wall, determining a second value of the physical property in the cavity, and detecting a difference between the first and second values.

A pressure accumulator having an accumulator housing (10) in which a movable separating element (16) separates a gas chamber (12) filled with a working gas from a fluid chamber (14) in a fluid-sealed manner. A monitoring device (46) is provided, which, in the event of a fault impairing the sealing effect of the separating element (16), provides an optically discernible indication and has an inspection window (54), through which an indicator can be observed. The monitoring device is connected to the gas chamber (12) and changes optical properties discernibly when wetted with the fluid. The indicator changing its optical properties is accommodated in a capsule (48) with a capsule wall (50) permeable to the passage of the fluid and arranged between the inspection window (54) and the separating element (16) in the accumulator housing (10).

Systems and methods for determining a pre-charge gas pressure in a gas-charged hydraulic accumulator are disclosed. For example, systems and methods for determining pre-charged gas pressure of a gas-charged hydraulic accumulator included as part of a vehicle are disclosed. Further, the present disclosure provides for determining a pre-charge gas pressure of a gas-charged hydraulic accumulator using a position sensor. The accumulator may form part of a hydraulic system used to move one part of the vehicle relative to another.

Systems and methods for determining a pre-charge gas pressure in a gas-charged hydraulic accumulator are disclosed. For example, systems and methods for determining pre-charged gas pressure of a gas-charged hydraulic accumulator included as part of a vehicle are disclosed. Further, the present disclosure provides for determining a pre-charge gas pressure of a gas-charged hydraulic accumulator using a position sensor. The accumulator may form part of a hydraulic system used to move one part of the vehicle relative to another.

A controller (45) is provided with an elapse time measuring section (47A) that measures an elapse time (tx) elapsed since an initial use of an accumulator (29) based upon a reset signal from a reset switch (44), a number-of-operations measuring section (47B) that measures a number of operations of the accumulator (29), that is, a number (N) of boom lowering operations after a reset, based upon a detection signal from an accumulator side pressure sensor (39), a gas permeation amount estimating section (47C) that estimates an estimation gas permeation amount (Qloss) of the accumulator (29), a sealed gas pressure estimating section (47D) that finds an estimation sealed gas pressure (Pgs) of a gas chamber (29B) of the accumulator (29), and an accumulator degradation determining section (47E) that determines a degradation condition of the accumulator (29) and outputs the determination result.

A controller (45) is provided with an elapse time measuring section (47A) that measures an elapse time (tx) elapsed since an initial use of an accumulator (29) based upon a reset signal from a reset switch (44), a number-of-operations measuring section (47B) that measures a number of operations of the accumulator (29), that is, a number (N) of boom lowering operations after a reset, based upon a detection signal from an accumulator side pressure sensor (39), a gas permeation amount estimating section (47C) that estimates an estimation gas permeation amount (Qloss) of the accumulator (29), a sealed gas pressure estimating section (47D) that finds an estimation sealed gas pressure (Pgs) of a gas chamber (29B) of the accumulator (29), and an accumulator degradation determining section (47E) that determines a degradation condition of the accumulator (29) and outputs the determination result.

A pressure accumulator includes an accumulator housing having first and second ports for receiving first and second pressure mediums, respectively, a movable separating element subdividing an interior of the accumulator housing into at least first and second working spaces, the first working space accommodating the first pressure medium and the second working space accommodating the second pressure medium, wherein the first port is in fluid communication with the first working space and the second port in fluid communication with the second working space. At least one sensor is operatively coupled to the first working space for measuring at least one characteristic of the first working space, and a gas generator is operative to generate a gas from ambient air, the gas generator including an outlet for outputting the generated gas, the outlet in fluid communication with the first port. A controller is operatively coupled to the at least one sensor and the gas generator, the controller configured to calculate an amount of gas in the first working space based on the at least one characteristic and upon the calculated amount of gas in the first working space being below a first threshold level, generate a command to introduce gas from the gas generator into the first working space.

A safety system has a valve block (10) to which at least one gas safety valve (12, 14) is connected in a detachable manner. At least one controllable valve (50, 52, 58) is in or at the valve block (10). At least one pressure accumulator (42) holds a gaseous pressure medium and is connected to the valve block (10) in a detachable manner. A gas-conveying connection routed at least partially within the valve block (10) between the connected pressure accumulator (42) and the connected gas safety valves (12, 14) can be opened or blocked by the valve (50, 52, 58).

A safety system has a valve block (10) to which at least one gas safety valve (12, 14) is connected in a detachable manner. At least one controllable valve (50, 52, 58) is in or at the valve block (10). At least one pressure accumulator (42) holds a gaseous pressure medium and is connected to the valve block (10) in a detachable manner. A gas-conveying connection routed at least partially within the valve block (10) between the connected pressure accumulator (42) and the connected gas safety valves (12, 14) can be opened or blocked by the valve (50, 52, 58).