Line pipe for the transport of deep-frozen media

Line pipe for the transport of deep-frozen media comprising:

• at least two corrugated metal tubes arranged concentrically and at a distance from one another;
• an insulation layer being arranged in the annular gap between the two metal tubes, the annular gap being evacuated;
• wherein a smooth walled metal tube is welded, vacuum tight, to the outer of said two metal tubes having an element to which a vacuum pump is connectable in a vacuum tight manner,
• wherein the element for the connecting of a vacuum pump is a closing valve provided with a valve body protruding into the interior of the smooth-walled metal tube which is welded to the same vacuum tight and which is flush with the outer surface area of the smooth-walled metal pipe,
• the valve body has a central threaded bore which is closed vacuum-tight by a screw plug during the operating conditions of the line pipe;
• and
• the valve body has threaded bores for the vacuum-tight connection of an adapter by use of screw bolts which serves to the vacuum-tight connection of a gas lock to which the vacuum pump is connectable.