The invention relates to a pumping system (1), in particular, for transporting gaseous and/or liquid media having two parallel hydraulically operated oscillating piston pumps (2, 3) whose pistons (8) are moved by means of electromagnetic fields, whereby the electromagnetic fields are generated in field coils (10, L1, L2) by means of half-wave direct current pulse. The invention distinguishes itself by a circuit arrangement (19) that can be connected to an alternating current source having two parallel electric branches that are connected to the field coils (L1, L2) of one of the oscillating pumps (2, 3) respectively, wherein the circuit arrangement (19) is equipped in such a way that the field coils (10, L1, L2) are operated electrically out of phase so that the oscillating piston pumps (2, 3) are operated with a phase displacement of 180. The invention further relates to a method for operating the pumping system electrically, and a circuit configuration for the pumping system and accordingly, for executing the method.

The invention relates to a pumping system (1), in particular, for transporting gaseous and/or liquid media having two parallel hydraulically operated oscillating piston pumps (2, 3) whose pistons (8) are moved by means of electromagnetic fields, whereby the electromagnetic fields are generated in field coils (10, L1, L2) by means of half-wave direct current pulse. The invention distinguishes itself by a circuit arrangement (19) that can be connected to an alternating current source having two parallel electric branches that are connected to the field coils (L1, L2) of one of the oscillating pumps (2, 3) respectively, wherein the circuit arrangement (19) is equipped in such a way that the field coils (10, L1, L2) are operated electrically out of phase so that the oscillating piston pumps (2, 3) are operated with a phase displacement of 180. The invention further relates to a method for operating the pumping system electrically, and a circuit configuration for the pumping system and accordingly, for executing the method.

This disclosure relates to a pump system for handling a slurry medium, the pump system comprising a pump unit (101) consisting of at least two reciprocating positive displacement slurry pumps, both pumps being arranged for alternating intake of slurry medium via a slurry suction inlet (103) and discharge of slurry medium via a slurry discharge outlet (103); a pump drive unit (104) for driving the at least two reciprocating positive displacement pumps of said pump unit; as well as a slurry damping pump unit (105) for damping discharge pulsations in the slurry medium being pumped.

This disclosure relates to a pump system for handling a slurry medium, the pump system comprising a pump unit (101) consisting of at least two reciprocating positive displacement slurry pumps, both pumps being arranged for alternating intake of slurry medium via a slurry suction inlet (103) and discharge of slurry medium via a slurry discharge outlet (103); a pump drive unit (104) for driving the at least two reciprocating positive displacement pumps of said pump unit; as well as a slurry damping pump unit (105) for damping discharge pulsations in the slurry medium being pumped.

A thick stock valve having a first through-opening, having a second through-opening and having a valve member associated with both through-openings. The valve member is mounted so as to be able to pivot about a pivot axis, wherein the valve member has a sealing face that is curved concentrically with the pivot axis. In a first state, the valve member releases the first through-opening and closes the second through-opening. In a second state, the valve member releases the second through-opening and closes the first through-opening. The valve member comprises a sealing part and a pivot part, wherein the pivot part is mounted so as to be able to rotate in the pivot axis and wherein the sealing part is connected to the pivot part via a connection structure.

The invention relates to a concrete pump assembly with at least two feed cylinders for conveying concrete, and at least two hydraulic drive cylinders moving the feed cylinders, wherein the drive cylinders are coupled to one another in a torsion-resistant manner via at least one connecting means. According to the invention, the drive cylinders and the at least one connecting means, in which the at least one valve is configured in an integrated manner, are formed as a drive unit that can be pre-assembled.

A cryogenic fluid pump includes an outlet tube extending along the pump centerline, the outlet tube having an outlet passage that is fluidly in communication with the combined outlet and with a pump outlet opening, and a shroud that extends concentrically along the outlet tube and has an inner diameter that is larger than an outer diameter of the outlet tube such that a gap is formed in a radial direction between an inner surface of the shroud and an outer surface of the outlet tube, the gap extending along at least a portion of the outlet tube.

The present invention discloses a hydraulically-driven double-acting mud pump, comprising power motors, pressure oil pumps, a three-position four-way hydraulically-actuated directional valve, a hydraulic power end and a mud pump head, the power motors being connected to the pressure oil pumps in a conventional way, the pressure oil pumps being communicated with a port P of the three-position four-way hydraulically-actuated directional valve via a pipeline, a port T of the three-position four-way hydraulically-actuated directional valve being communicated with an oil tank via a pipeline, a port A and a port B of the three-position four-way hydraulically-actuated directional valve being both connected to the hydraulic power end, the hydraulic power end being connected to the mud pump head in a conventional way, a lower end of the mud pump head being communicated with a low-pressure manifold and two sides of the mud pump head being communicated with a high-pressure manifold. The hydraulically-driven double-acting mud pump of the present invention allows for more stable instantaneous flow and pressure of the discharged liquid from the mud pump and reduced fluctuation.

A pressure-maintaining valve arrangement of a purge circuit of a closed hydraulic circuit includes a pressure-maintaining valve configured to be shut off via a pilot valve. In one embodiment, a control pressure chamber, acting in the closing direction, of the pressure-maintaining valve is configured to be relieved via the pilot valve to a tank, and the pressure-maintaining valve is closed via a spring acting in the closing direction. In another embodiment, the valve arrangement includes an additional control pressure chamber acting in the closing direction. The additional control pressure chamber is configured to be loaded via the pilot valve, and the pressure-maintaining valve closes. The pressure of the inlet of the pressure-maintaining valve is used for this purpose.

A pressure-maintaining valve arrangement of a purge circuit of a closed hydraulic circuit includes a pressure-maintaining valve configured to be shut off via a pilot valve. In one embodiment, a control pressure chamber, acting in the closing direction, of the pressure-maintaining valve is configured to be relieved via the pilot valve to a tank, and the pressure-maintaining valve is closed via a spring acting in the closing direction. In another embodiment, the valve arrangement includes an additional control pressure chamber acting in the closing direction. The additional control pressure chamber is configured to be loaded via the pilot valve, and the pressure-maintaining valve closes. The pressure of the inlet of the pressure-maintaining valve is used for this purpose.