An apparatus for adding, from a gas container with a gas under an overpressure via a pressure reducing valve unit to a bottle fully or partly filled with a liquid while utilizing a two-part valve arrangement. The first part of the arrangement is related to the valve unit and a second part of the arrangement is related to the bottle. The two parts of the valve arrangement are easily coordinated with each other and easily separable. One valve part is adapted to enclose a first check valve which, when being mechanically influenced, allows gas flow from the container and into the bottle. The other valve part is adapted to enclose a second check valve which, when being pneumatically influenced, allows gas flow into the bottle.
