pincer gripper 21 having a notch in which pipeline 2 may engage upon the positioning of the gripper gripper 21 is mounted on a support 23 so as to be swivellable about an axis of rotation 22 support 23 is mounted so that it is displaceable in the lengthwise direction a plurality of compression springs 24 act on this support and press the support and pincer gripper 21 into their upper starting position gripper 21 then assumes the position designated 21 a gripper 21 has a curved shoulder 210 on which a displaceable cam 25 acts displaceable cam 25 is displaceable in the lengthwise direction cam 25 is attached to a piston rod 26 of a hydraulic cylinder 27 in its starting position 25 a cam 25 adjoins shoulder 210 of gripper 21 a which is held in this starting position by a restoring spring 28 when cam 25 travels downwards into the position designated 25 gripper 21 is forced into its other end position wherein it surrounds pipeline 2 cam 25 then lies against a projection 29 provided on support 23 when cam 25 travels further gripper 21 is thus likewise lowered positions itself against union nut 4 and presses the pipeline against receptacle 5 fig2 shows the other end of pipeline.