| 摘要 |
<p>PURPOSE:To improve the heat insulating performance of a feed water pipe by mounting a vacuum double pipe, constituted in such a way as to form a vacuum space between an outer cylinder and the outer peripheral part of an inner cylinder, to the outer periphery of the inner cylinder to form a heat insulating device in an antifreezing pipe for preventing the freeze of the feed water pipe to a household. CONSTITUTION:This antifreezing pipe 1 is formed of a feed water pipe 2, a vacuum double pipe 4 and a fixing member 3. The vacuum double pipe 4 is formed of an inner cylinder 5, an outer cylinder 6 and a connecting member 8. A vacuum pump is connected to a tip pipe 7 provided at the outer cylinder 6, and after letting air out of a space part S close into the nearly vacuum state, the vacuum double pipe 4 is put in a furnace to further let air out of the space part S in the high temperature state of about 450 deg.C. The tip pipe 7 is then crushed to seal the space part (vacuum space) S. In this heating treatment, the connecting member receives reverse direction force at the heating time and cooling time, but since the connecting member 8 is provided in such a way as to have freedom to vertical deformation, the deformation and damage of a device is avoided.</p> |
