The invention relates to a metering pump having a hydraulic drive (12) for supplying a hydraulic fluid under pressure. The metering pump furthermore comprises a housing (2) and an oscillating piston (3), which is accommodated in the housing (2) in such a way that at least a first and a second hydraulic chamber (9-1, 9-2) and a first (6-1) and a second delivery chamber (6-2) are formed, wherein the oscillating piston (3) has at least a first driving surface (10-1) in the first hydraulic chamber (9-1) and at least a second driving surface (10-2) in the second hydraulic chamber (9-2), and the hydraulic chambers (9-1, 9-2) communicate with the hydraulic drive, thus enabling the oscillating piston (3) to be moved backward and forward between a first and a second position by the hydraulic fluid, wherein, during the movement from the first to the second position, the volume of the first delivery chamber (6-1) is enlarged and the volume of the second delivery chamber (6-2) is reduced and, during the movement from the second to the first position, the volume of the second delivery chamber (6-2) is enlarged and the volume of the first delivery chamber (6-1) is reduced. The invention furthermore relates to a metering system for mixing two fluids and a metering system for metering at least one fluid.

A linearly actuated hydraulic piston pump is provided. The pump includes a piston disposed between a first section and a second section of a piston chamber. The pump also includes a control valve having a valve body defining a valve chamber therein. The control valve also includes an inlet port, a first port, a regeneration port, a second port, and a spool. The spool in a first spool position fluidly couples a pressurized fluid source to the first section via the inlet port and the first port, and fluidly couples an accumulator to the second section via the regeneration port and the second port. The spool in the second spool position fluidly couples the first section to a drain via the first port and a drain port, and fluidly couples the second section to the pressurized fluid source via the inlet port and the second port.

A pressure amplifier (1) is described comprising a housing (2), an amplification piston (5) in the housing (2) having a high pressure area (9) in a high pressure chamber (5) and a low pressure area (8) in a low pressure chamber (3), and a switching valve (11) having a pressured control valve element having a larger pressure area (16) and a small pressure area (17). Such a pressure amplifier should have a high operating frequency. To this end the valve element (10) and the amplification piston (5) are located in a same bore (3, 4) in the housing (2).

A pressure amplifier (1) is described comprising a housing (2) a low pressure chamber (9-12), a high pressure chamber (13-16) and for transmitting means between the low pressure chamber (9-12) and the high pressure chamber (13-16). Such a pressure amplifier should have a compact design. To this end the force transmitting means comprise a rotor (3) arranged in a bore (4) of the housing (2), wherein the rotor (3) comprises a radially extending low pressure wing (5, 6) and a radially extending high pressure wing (7, 8), the low pressure wing (5, 6) together with the housing (2) delimiting the low pressure chamber (9-12) and the high pressure wing (7, 8) together with the housing (2) delimiting the high pressure chamber (13-16), wherein a supply of fluid into the low pressure chamber (9-12) causes a rotation of the rotor (3) and a rotation of the rotor causes a decrease of volume of the high pressure chamber (13-16).

A hydraulic pressure intensifier (1) is described comprising a housing (2) having a low pressure chamber (3) and a high pressure chamber (4), force transmitting means (5) between the low pressure chamber (3) and the high pressure chamber (4), and a switching valve (8) connecting the low pressure chamber (3) to a first pressure or to a second pressure different from the first pressure. It is intended to have a large volume on the high pressure side of the pressure intensifier. To this end the switching valve (8) is controlled by a pilot valve 18.

The temperature of a working medium is managed appropriately. A pressure intensifier includes a double-acting drive cylinder having first and second compartments separated by a piston driven by a working medium, high-pressure cylinders that discharge the fluid, a closed-circuit working medium pump that drives the pressure intensifier by sucking and discharging the working medium from and to the first and second compartments, first and second working medium channels, a collector that collects the working medium from the first and second working medium channels into a tank, and a low-pressure selector that selects, when the pressure of the working medium discharged toward the first or second compartment exceeds a predetermined threshold, the working medium discharged from the first or second compartment, and directs the selected working medium to the collector.

Pumps are provided, more particularly piston type pumps having increased energy efficiency, systems incorporating such piston type pumps, and methods of operating piston type pumps. The pumps are suitable for pumping of oil from an oil well or for pumping other liquids such as ground water, subterranean liquids, brackish water, sea water, waste water, cooling water, gas, coolants, and the like.

A dual-function high-pressure relief valve pressure regulating valve includes valve sleeve, a spool that slides laterally in a first direction and a second direction, and a piston disposed against the valve sleeve. The valve sleeve includes a PRV inlet window, a PRV outlet window, and a pressure relief outlet window. The spool includes a PRV inlet landing, and a combined PRV/HPRV landing. The piston is configured to slide laterally in the first direction and the second direction based on a pressing force applied by the spool. The dual-function HPRV-PRV operates in a first mode to adjust the spool and maintain opening of the PRV inlet window and the PRV outlet window while closing the pressure relief outlet window, and operates in a second mode to adjust both the spool and the piston to open each of the PRV inlet window, the PRV outlet window, and the pressure relief outlet window.

A dual-function high-pressure relief valve pressure regulating valve includes valve sleeve, a spool that slides laterally in a first direction and a second direction, and a piston disposed against the valve sleeve. The valve sleeve includes a PRV inlet window, a PRV outlet window, and a pressure relief outlet window. The spool includes a PRV inlet landing, and a combined PRV/HPRV landing. The piston is configured to slide laterally in the first direction and the second direction based on a pressing force applied by the spool. The dual-function HPRV-PRV operates in a first mode to adjust the spool and maintain opening of the PRV inlet window and the PRV outlet window while closing the pressure relief outlet window, and operates in a second mode to adjust both the spool and the piston to open each of the PRV inlet window, the PRV outlet window, and the pressure relief outlet window.