| 摘要 |
PROBLEM TO BE SOLVED: To prevent a sliding part from being influenced by a gas channel at all, to prevent the adhesion of a foreign object, and to perform positive operation even in the case of abnormality, by nearly completely blocking the part between a valve body and a flange by a second main spring bracket while a valve is opened. SOLUTION: For a gas shut-off valve, a second main spring bracket 13 that is placed outside a main spring 14 and covers the periphery of a sliding part 21 is inserted into the side of a flange 6. The main spring 14 is elastically provided between a first main spring bracket 12 that is positioned by an E ring 11 being inserted into a plunger 1 and a second main spring bracket 13, thus nearly completely blocking the part between a valve body pad 16 and the flange 6 by the second spring bracket 13 while the valve is open (has returned), and hence preventing a foreign object from adhering to the sliding part 21 without being entirely affected by a gas channel. Even in cut-off, the sliding part 21 is placed inside a recessed part 13a of the second main spring bracket 13 for preventing the adhesion of the foreign object. In this manner, the foreign object is not allowed to adhere to the sliding part 21 merely by adding the second main spring bracket 13.
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