| 摘要 |
PURPOSE:To enable to prevent reliably destruction of a heat collector resulting from freezing of the heat collector by providing a pressure release valve between a gate valve and the heat collector and by destructing a thin metal plate of the pressure release valve preferentially upon sensing of a hydraulic pressure increase. CONSTITUTION:A pressure release valve 17 is caused to be actuated at pressure of about 2-5kg/cm<2> and blind plugs 10 and 10 are caused to be removed off from a protruded pipe 5 at the pressure of about 3-7kg/cm<2> which is a little higher than a working pressure of the pressure release valve 17 by providing the pressure release valve 17 between switching valves 14 and 15 and a heat collector 4 and applying a thin copper plate 18 of about 0.05 millimeters thick to the pressure release valve 17. Then, the thin metal plate 18 of the pressure release valve 17 is destructed through an increase of hydraulic pressure preferentially, through which the heat collector is prevented reliably from destructing by freezing. |
