| 摘要 |
<p>A duct system for low-temperature fluids, especially low-boiling-point gases such as helium, and for thermally isolated electrical conductors wherein an evacuated outer rigid conduit surrounds the fluid-carrying duct which consists of a foil flexible and nonsupporting at room temperature but reinforced by a helical strip. The foil preferably consists of polyethyleneterephthalate.</p> |
