| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the impossibility of draining even in a freezing environment. <P>SOLUTION: The drainage level of a water storage tank 5 for collecting and storing water in a gas piping is made variable, and water in the storage tank 5 is allowed to be drained from a drain outlet at a different drainage level according to a condition. For instance, a drain valve 6 installed in the storage tank 5 is used as a first drain means, and when drainage by the drain valve 6 is impossible, a relief valve 7 having a drainage level higher than that of the drain valve 6 is used as a second drain means to carry out drainage by the relief valve 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
