| 摘要 |
PROBLEM TO BE SOLVED: To provide an antifreezing device for header piping simple in operation, low in running cost, having little possibility of piping being restricted in consideration of draining and proving no hindrance for draining even if the number of piping is large. SOLUTION: Antifreezing treatment such as thermal insulation is applied to a riser 1 rising from an underground service pipe and to a cut-off valve 3 connected thereto. A water supply header 9 and a hot water supply header 10 are connected to the lower reaches side of the cut-off valve, and an electric suction device 16 capable of sucking both water and air is connected further to the lower reaches side through an electrically driven selector valve 15. When draining water, the water supply header 9 and the hot water supply header 10 are controlled to be opened/closed in order by the electrically driven selector valve 15, and the electric suction device 16 is operated for a fixed time to forcibly drain water in the piping.
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