The system utilizes fluid pressure achieved by increasing depth as a primary component for generation of energy. The system operates by varying its depth through changes in buoyancy. The ballast changes are controlled by electronics powered by a battery charged by a generator driven by a hydraulic system. Rather than utilizing a motor driven pump to generate pressure in the hydraulic system, a piston-like cylinder is applied pressure by the change in hydrostatic pressure as depth increases and draws fluid back into the cylinder as pressure decreases. As the system sinks, outside pressure forces hydraulic fluid to power a generator that charges a battery and powers a pump to deballast. As the system rises, the lowering of ambient pressure, and other internal forces, causes the hydraulic fluid to return to its initial state, where once the ballast begins to take in fluid, the whole process will continue to repeat.

The system utilizes fluid pressure achieved by increasing depth as a primary component for generation of energy. The system operates by varying its depth through changes in buoyancy. The ballast changes are controlled by electronics powered by a battery charged by a generator driven by a hydraulic system. Rather than utilizing a motor driven pump to generate pressure in the hydraulic system, a piston-like cylinder is applied pressure by the change in hydrostatic pressure as depth increases and draws fluid back into the cylinder as pressure decreases. As the system sinks, outside pressure forces hydraulic fluid to power a generator that charges a battery and powers a pump to deballast. As the system rises, the lowering of ambient pressure, and other internal forces, causes the hydraulic fluid to return to its initial state, where once the ballast begins to take in fluid, the whole process will continue to repeat.

A valve, with a valve housing, through which process medium can flow and in which a valve seat which surrounds a throughflow opening is arranged, to which valve seat a valve element which is arranged on a spindle is assigned in a manner such that the valve element by way of an actuation travel of the spindle is movable between a shut-off position, in which the valve element sealingly bears on the valve seat in a process-medium-tight manner, and an open position, in which the valve element is lifted from the valve seat, and with a fluid-actuated valve drive which includes a drive housing and a drive wall which together with the spindle forms a drive unit and which separates two working spaces from one another, of which working spaces at least one can be subjected to pressure, and with a travel limitation device which for limiting the opening travel of the spindle includes a stop element which is fastened to the drive housing and which with an end section which includes a stop surface projects into a travel limitation space, in which the drive unit can strike upon the stop surface for limiting the opening travel, the travel limitation space is constantly under atmospheric pressure and the stop element is formed by a shock absorber housing of a shock absorber.

A valve, with a valve housing, through which process medium can flow and in which a valve seat which surrounds a throughflow opening is arranged, to which valve seat a valve element which is arranged on a spindle is assigned in a manner such that the valve element by way of an actuation travel of the spindle is movable between a shut-off position, in which the valve element sealingly bears on the valve seat in a process-medium-tight manner, and an open position, in which the valve element is lifted from the valve seat, and with a fluid-actuated valve drive which includes a drive housing and a drive wall which together with the spindle forms a drive unit and which separates two working spaces from one another, of which working spaces at least one can be subjected to pressure, and with a travel limitation device which for limiting the opening travel of the spindle includes a stop element which is fastened to the drive housing and which with an end section which includes a stop surface projects into a travel limitation space, in which the drive unit can strike upon the stop surface for limiting the opening travel, the travel limitation space is constantly under atmospheric pressure and the stop element is formed by a shock absorber housing of a shock absorber.

A valve piston has a central axis along which mutually spaced control geometries are provided, which are bypassed by a passage that extends through the valve piston. The valve piston is, at least in portions, manufactured additively. A valve is includes a valve housing and a housing recess, in which the valve piston is received so that it is adjustable relative to the valve housing.

A valve piston has a central axis along which mutually spaced control geometries are provided, which are bypassed by a passage that extends through the valve piston. The valve piston is, at least in portions, manufactured additively. A valve is includes a valve housing and a housing recess, in which the valve piston is received so that it is adjustable relative to the valve housing.

Unloader for a compressor, said unloader (1) comprising a housing (2) with an inlet (3) and an outlet (4), and whereby the unloader (1) is further provided with a piston rod (5) which is arranged moveably in a reciprocating manner in the housing (2), whereby on one end (5a) of the piston rod (5) a valve (7) is provided to be able to close the outlet (4) and whereby on the other end (5b) of the piston rod (5) a piston (8) is arranged, the piston being arranged moveably in a reciprocating manner in a thereto provided cavity (9) of the unloader (1), said cavity (9) being at least partially delimited by a lid (10) which is provided on the housing (2) and which is also part of the unloader (1), whereby sealing means (11) are provided for the leakage-free movement of the piston (8) in said cavity (9), whereby the cavity (9) in which the piston (8) is arranged moveably in a reciprocating manner is provided at least partially in the lid (10).

A pneumatic-hydraulic control valve includes a valve base and a valve stem movably disposed in the valve base. A first inner oil guiding hole of the valve stem communicates with a first outer oil guiding hole of the valve base. A second inner oil guiding hole of the valve stem does not communicate with a second outer oil guiding hole of the valve base when the valve stem is closed, and communicates with the second outer oil guiding hole of the valve base when the valve stem is opened. Further, the valve stem has a first stressed portion for bearing a fluid closing force and a second stressed portion for bearing a fluid opening force. The outer diameter of the first stressed portion is larger than that of the second stressed portion. Thus, the present invention reduces a valve opening force without affecting the sealing effect.

For determining the operability of a fluid driven safety valve, a method comprising the following steps is described: A partial stroke test is performed on the safety valve, resulting in a stroke-pressure curve. The stroke pressure curve is extrapolated (330, 340) beyond the measured range (360) up to the safety closing position (350). From the extrapolated stroke-pressure curve, the closing pressure reserve (320) can be determined. In this way, the functionality of the safety valve can be checked during operation.

An insert safety valve includes a valve body having a valve member, and a control fluid conduit fluidically connected to the valve body. The insert safety valve being responsive to a control fluid at a first pressure to shift the valve member and open the valve body to a fluid flow and at a second pressure to add the control fluid to the fluid flow.