| 摘要 |
PURPOSE:To prevent the intrusion of vapor in a tank into a housing when a liquid level detecting body is repaired and checked, by a constitution, in which a float valve body, whose floating is suppressed, is lifted together with an anchor weight and the lower edge of a tube body is closed. CONSTITUTION:When a length measuring line of a liquid-level detector 15, which is moved up and down with the fluctuation of the liquid level, is cut, winches 10 are driven and an anchor weight 13 is lifted by suspending wires 12. Then a float valve body 20 is lifted at the same time and a tube body 21 is tightly closed. The lower end of the tube body 21 is extended to the lower part from the liquid surface at the normal time. Therefore, the intrusion of the vapor in a tank into a housing 2 is prevented by the float valve body 20, and the repair and check of the liquid level detector 15, which is lifted in the housing 2, can be performed safely. When the liquid level does not reach the lower end of the tube body 21, an opening part 5 is closed by the lifted anchor weight 13. |
