| 摘要 |
PROBLEM TO BE SOLVED: To provide a butterfly valve which, when the valve element is deflected by a fluid pressure at the time of a closed state of the butterfly valve, prevents the occurrence of a leakage within the valve element, the leakage within the valve element being the leakage of the fluid into a gap between a valve shaft hole in the valve element and a valve shaft, and a leakage at the valve shaft, the leakage at the valve shaft being the leakage of the fluid into the shaft seal section between a through-hole in a seat ring and the valve shaft, from being caused and improves assemblability of the seat ring and the valve element to the valve body. SOLUTION: The butterfly valve includes a seat ring 2 which is fitted to the inner peripheral surface of the valve body 1, a valve shaft 3 which penetrates through the through-hole 11 in the seat ring 2 and is supported by the valve body 1, and a circular plate-like valve element 4 which has the valve shaft 3 mounted in a valve shaft hole 15 and supports the valve shaft. In this butterfly valve that is opened and closed by rotating the valve element 4 with rotation of valve shaft 3, a hollow cylindrical bush 5 is fitted in the through-hole 11 in the seat ring 2 and is fitted in a water-tight manner to a valve shaft fitting hole 16 which is provided in the valve element 4 so as not to protrude from the outer peripheral surface of the seat ring 2. COPYRIGHT: (C)2011,JPO&INPIT |
