| 摘要 |
<p>An on-off valve having long service life. The on-off valve (70) has metal (76) having a low melting point. When a shutoff member (72) is made to contact with the surface of the low melting point metal (76) with the low melting point metal (76) being in a molten state, an inner space of the on-off valve (70) becomes a closed state in which the inner space is separated into an inner space and an outer space of the shutoff member (72). If the inner space and the outer space, originated from the inner space of the on-off valve (70), of the shutoff member (72) are connected to each other, external devices are shut off from each other in the closed state. In an open state in which the lower end of the shutoff member (72) is separated from the low melting point metal (76), the external devices are connected to each other.</p> |
