Abstract: An assembly including a valve unit, a suck-back unit and a valve body is proposed, the valve body including a first channel portion which leads into a first chamber having a valve seat; the valve body including a second channel portion which connects the first chamber to a second chamber; the valve body including a third channel portion which leads away from the second chamber; the valve unit including a first actuator; the first actuator closing a connection between the first channel portion and the second channel portion when said actuator is pressed against the valve seat; and the suck-back unit including a second actuator, the second actuator, when retracted inside the second chamber, sucking back a fluid in the third channel portion towards the second chamber if the connection between the first channel portion and the second channel portion is closed.

Abstract: The invention relates to a coupling for releasably connecting pipes or pipe-like elements in a fluid-tight manner, having a first coupling part and a second coupling part which are connectable via a screw nut or the like, wherein the coupling parts are each provided with a radially outwardly extending flange and the flanges have end faces which are provided with a profile for sealing off the coupling, wherein the profile comprises at least one circumferential groove and at least one circumferential protrusion engaging in the groove, said groove and protrusion forming a fluid-tight seal between one another in the coupled state, and wherein the protrusion comprises a lateral sealing face which has an outwardly bulging shape in cross section, and wherein the groove has a corresponding lateral counterpart sealing face that is inclined with regard to the longitudinal axis of the coupling, such that, in the installation position, the sealing face of the protrusion is pressed against the counterpart sealing face of