Abstract: A device for feeding one or more substances thixotroping a liquid to a container for storing said liquid, is characterized in that the device comprises a tank containing thixotroping substances, a feeding means for transportation of the thixotroping substances from the tank into the container which contains the liquid, and a pressure generating means for generating a pressure gradients in the thixotroping substances within the feeding means which is directed from the tank to the container. By means of the device according to the invention thixotroping substances can be fed into fluid within the container, in order to prevent discharging and leakage respectively under certain defined circumstances.