Filler

A filler including a storage tank for storing a first gas and a liquid, a supply of a second gas, a filling valve connected to the storage tank and the supply, a receptacle disposed below the filling valve and on which a vessel is placed, and means for detecting a filled volume of liquid, the filling valve comprising a liquid passage connected to the storage tank for feeding the liquid into the vessel, a liquid valve for opening and closing the liquid passage, a first gas passage connected to the storage tank for feeding the first gas into the vessel, a first gas valve for opening and closing the first gas passage, a second gas passage connected to the supply for feeding the second gas into the vessel, a second gas valve for opening and closing the second gas passage, a first gas discharge passage for providing a communication between the interior of the vessel and an exterior thereof, and a first gas discharge valve for opening and closing the first gas discharge passage, and further including a controller for receiving a signal from the means for detecting the filled volume and for closing the liquid passage when the filled volume in the vessel reaches a given value;

• characterized in that the pressure of the second gas of the supply is chosen to be equal to or higher than the pressure in the storage tank, the controller being adapted to control at least the liquid valve such that upon completion of a preliminary substitution of a vessel interior with the first gas by opening the first gas discharge valve and the first gas valve, followed by a proper substitution of the vessel interior with the second gas by opening the second gas valve and the first gas discharge valve while closing the first gas valve, and subsequently followed by a pressurization of the vessel interior to a pressure equal to or higher than the pressure in the storage tank, the controller subsequently allowing the liquid valve to be opened as the second gas valve is closed and the first gas valve is opened to fill the vessel with the liquid while discharging the gas in the vessel to the storage tank through the first gas passage, the controller closing the liquid valve to stop a filling operation when the filled volume in the vessel reaches a given value.