| 摘要 |
<p>PURPOSE: To make compression of an extra insulated layer remain in as small a range as possible by holding the extra insulated layer by a spacer provided on a metallic pipe spirally put with an inward waveform with an interval against the metallic pipe put with the inward waveform. CONSTITUTION: An extra insulated layer 5 spirally wound constituted of an insulating material and a reflective material and constituted of layers alternately and vertically provided is provided in a ring clearance 8 of two metallic pipes 1, 6 concentrically put with a waveform. This extra insulated layer 5 is held with a clearance against the metallic pipe 1 pu with this inward waveform by a spacer 4 provided on the metallic pipe 1 spirally put with the inward waveform, and a winding direction of the extra insulated layer 5 is directed in the opposite direction of the winding direction of the spacer 4.</p> |
