Tap with incorporated air passageway

A tap comprising a hollow body including a liquid inlet, an air inlet, a liquid outlet, an air outlet, and a divider element dividing the interior of the body into a liquid flow passageway between the liquid inlet and the liquid outlet and an air flow passageway between the air inlet and the air outlet, a section of the air flow passageway being separated from the liquid flow passageway, the separate section having an inlet and an outlet, a valve system for controlling liquid and air flow in the passageways, and a push button connected to the body for operating the valve system, wherein the air inlet and the liquid outlet are adjacent to each other and the valve system comprises a valve element movable by pressure applied to the push button from a first position in which it closes the liquid outlet and prevents liquid flow from the tap to a second position in which liquid flows from the tap, the valve element also controlling air flow in the air flow passageway and the valve element when in the first position being adjacent to but spaced from the inlet to the separate section of the air passageway.