Abstract: Apparatus for filling successive containers with a liquid, such as a carbonated beverage, has a rotary vessel with a bottom wall which carries an annulus of tubular extensions each of which is surrounded by a metering chamber. Each extension and the associated metering chamber supports a filling unit with a twin-seat valve having a single valving element which is movable between an upper position to seal an outlet at the lower end of the extension from an adjacent inlet of the metering chamber while permitting the outlet of the metering chamber to discharge a metered quantity of liquid into a container below the filling unit, and a lower position in which the single valving element seals the outlet of the metering chamber but permits the extension to admit liquid into the metering chamber.