For connection of pipelines which are subject to vibration, for example pipelines in vehicle exhaust systems, a liquid-tight decoupling element is used which includes a, e.g. multi-layer wound, metal hose and a tube accommodated in coaxial relationship inside or outside of the metal hose. A first axial fitting firmly secures one end of the tube. The tube is sized to protrude into a second axial fitting, regardless whether the metal hose is completely compressed or completely stretched, to allow movement of the tube in axial and torsional directions in relation to the second axial fitting.