Flushable pressure vessel

A method of filling a pressure vessel with a filling gas at a desired degree of purity, the pressure vessel comprising:

• an inner vessel produced from an inner vessel material having a cylindrical middle part having a cylinder axis and having first and second terminal caps that seal the cylindrical middle part so as to provide a storage volume in the pressure vessel;
• an outer layer applied on the inner vessel in order to reinforce said inner vessel;
• a valve connection piece on the second terminal cap;
• 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, the flushing lance having a first end facing the first terminal cap, which lies opposite the valve connection piece in the storage volume;
• and
• an additional weight arranged on the first end of the flushing lance,
• the method comprising:
• filling the pressure vessel with the filling gas for a gas exchange with the storage volume by way of the flushing lance that protrudes into the storage volume and is provided with a perforation along its entire length up to the first end of the flushing lance;
• performing the gas exchange up to the opposite terminal cap, in that the flushing lance extends far enough to the first terminal cap;
• subsequently pumping out a resultant mixed gas filling that is located in the pressure vessel through the flushing lance to the exterior of the pressure vessel;
• and
• repeating the filling the pressure vessel, the performing the gas exchange, and the pumping out of the resultant mixed gas filling until the gas filling in the pressure vessel corresponds to the filling gas at the desired degree of purity.

A method of producing a pressure vessel, the method comprising:

• providing an inner vessel produced from an inner vessel material having a cylindrical middle part with a cylinder axis and having first and second terminal caps that seal the cylindrical middle part so as to provide a storage volume, the inner vessel comprising an outer layer that is applied thereto in order to reinforce the inner vessel, wherein a valve connection piece is provided on the second terminal cap so as to receive a valve in order to seal the storage volume;
• guiding a hollow flushing lance that is open to the outside through the valve connection piece, wherein the flushing lance is configured so as to protrude 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 first terminal cap, which lies opposite the valve connection piece in the storage volume for a gas exchange with the storage volume, wherein an additional weight is arranged on the first end of the flushing lance, and wherein the flushing lance extends so far to the first terminal cap that the gas exchange is performed throughout the perforation of the flushing lance up to the first terminal cap;
• and
• fixing the flushing lance to the valve connection piece so that the flushing lance is held by the valve connection piece in a sealing manner with respect to the valve connection piece.