Abstract: Device for transferring liquid under simple or accelerated gravity of a tubular-type stopper device equipped with an external thread having the same diameter and pitch as the internal screw thread of a tapped drain hole of a container. The tubular-type stopper device is screwed into the container so the tapped drain hole is a leaktight bore. A bore is normally closed by a check valve equipped with an annular gasket and a return spring. The check valve is actuated in the open position by an adapter, and a removable linkage between the stopper and the adapter are provided in order to enable the adapter to be fastened to the stopper when the container is drained. Axial linkages between the check valve and its annular gasket are formed by an annular groove in the check valve and a semi-rigid tubular member snapped over a portion of the head of the check valve to retain the gasket in position.