Flushable pressure vessel

A pressure vessel, comprising an inner vessel produced from an inner vessel material having a cylindrical middle part with a cylinder axis and having two terminal caps that seal the cylindrical middle part so as to provide a storage volume in the pressure vessel, an outer layer which is applied on the inner vessel in order to reinforce said inner vessel, a valve connection piece that is arranged on one of the terminal caps so as to fill and empty the storage volume with a filling gas at a desired degree of purity, and a hollow flushing lance that is open to the outside and is guided through the valve connection piece and held therein in a sealing manner with respect to the valve connection piece, wherein the flushing lance protrudes into the storage volume and is provided with a perforation along its entire length up to a first end of the flushing lance facing the terminal cap that lies opposite the valve connection piece in the storage volume for a gas exchange with the storage volume, wherein the flushing lance extends so far to the terminal cap, which lies opposite the valve connection piece, that the gas exchange takes place throughout the perforation of the flushing lance up to the opposite terminal cap, the flushing lance being produced at least in the area within the storage volume from a dimensionally stable material, wherein the first end of the flushing lance is arranged free-floating in the storage volume of the pressure vessel,

• characterized in that
• an additional weight is arranged on the first end of the flushing lance.