| 摘要 |
PROBLEM TO BE SOLVED: To provide a butterfly valve device provided in a fluid pipe, fulfilling a desired valve closing function even when a valve element is stopped in a deviated state from a valve closing position, and facilitating replacement of a seal packing in maintenance and inspection. SOLUTION: The butterfly valve device has: a casing 2 having a circular valve opening with a center point on a flow passage axis A1; the valve element 3 formed of a circular plate drawing a circle coaxial with the valve opening; and a driving shaft 4 positioned further on the inside of the casing 2 than the valve opening and forming a rotary shaft crossing with the flow passage axis A1. A valve seat face 12 is provided on the inner peripheral face of the valve opening, and a seal face 16 is provided on the outer peripheral face of the valve element 3 connected to the valve seat face 12. The valve seat face 12 and the seal face 16 form a sliding face 25 having circular arc faces 13, 18, 19 forming an arc in the direction of the flow passage axis A1, based on a radius with an intersection between the flow passage axis A1 and the rotary shaft as the center, and the seal packing 17 is provided on the seal face 16. COPYRIGHT: (C)2011,JPO&INPIT
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