Abstract: A pressure exchanger (1) including a housing (2), a drive shaft (3) and a cylinder drum (4) rotatably arranged in the housing (2) is described, the cylinder drum (4) including two front faces and at least one cylinder (5) between the front faces, wherein the housing (2) includes a port flange (7, 8) at each end of the cylinder drum (4) and at least at one end of the cylinder drum (4) a pressure shoe (18) is arranged between the cylinder drum (4) and the port flange of this end. Such a pressure exchanger should be operated in a cost-effective manner. To this end an adjustable stop arrangement (19) is arranged between the pressure shoe (18) and the cylinder drum (4).

Abstract: A piston (1) having a piston shaft (2), a ball head (3) at one end of the piston shaft (2), and a slider shoe (4) mounted to the ball head (3), wherein the ball head (3) has a through channel (5), the slider shoe (4) has a sliding surface (6) and a through hole (7) in communication with an end of the through channel (5), and a plastic material (8) is arranged in a gap between the slider shoe (4) and the ball head (3) and forms an inner coating (9) of the through hole (7). The production of such a piston should be facilitated. To this end a sealing surface (14) is arranged at the end of the through channel (5) wherein the sealing surface (14) surrounds the opening of the through channel (5) into the through bore (7) and an inner diameter of the sealing surface (14) is smaller than an inner diameter of the inner coating (9) of the through bore (7).

Abstract: A piston (1) having a piston shaft (2), a ball head (3) at one end of the piston shaft (2), and a slider shoe (4) mounted to the ball head (3), wherein the ball head (3) has a through channel (5), the slider shoe (4) has a sliding surface (6) and a through hole (7) in communication with an end of the through channel (5), and a plastic material (8) is arranged in a gap between the slider shoe (4) and the ball head (3) and forms an inner coating (9) of the through hole (7). The production of such a piston should be facilitated. To this end a sealing surface (14) is arranged at the end of the through channel (5) wherein the sealing surface (14) surrounds the opening of the through channel (5) into the through bore (7) and an inner diameter of the sealing surface (14) is smaller than an inner diameter of the inner coating (9) of the through bore (7).

Abstract: A tube assembly (12) including an inner tube (13) having an outer thread (15), an outer tube (14) having an inner thread (16) engaging the outer thread (15), at least for securing an angular position between the inner tube (13) and the outer tube (14) is provided. Such a tube assembly should facilitate mounting and maintenance of a reverse osmosis system. To this end, the inner tube (13) includes at least an groove (17) on its outer surface and the outer tube (14) includes an recess (18) on its inner surface, wherein a blocking element is arranged in a space formed by the recess (18) and the groove (17) in overlapping relation with the groove (17) and the recess (18).

Abstract: A pressure exchanger (1) including a housing (2), a drive shaft (3) and a cylinder drum (4) rotatably arranged in the housing (2) is described, the cylinder drum (4) including two front faces and at least one cylinder (5) between the front faces, wherein the housing (2) includes a port flange (7, 8) at each end of the cylinder drum (4) and at least at one end of the cylinder drum (4) a pressure shoe (18) is arranged between the cylinder drum (4) and the port flange of this end. Such a pressure exchanger should be operated in a cost-effective manner. To this end an adjustable stop arrangement (19) is arranged between the pressure shoe (18) and the cylinder drum (4).

Abstract: A tube assembly (12) including an inner tube (13) having an outer thread (15), an outer thread (14) having an inner thread (16) engaging the outer thread (15), at least for securing an angular position between the inner tube (13) and the outer tube (14) is provided. Such a tube assembly should facilitate mounting and maintenance of a reverse osmosis system. To this end, the inner tube (13) includes at least an groove (17) on its outer surface and the outer tube (14) includes an recess (18) on its inner surface, wherein a blocking element is arranged in a space formed by the recess (18) and the groove (17) in overlapping relation with the groove (17) and the recess (18).