| 摘要 |
PROBLEM TO BE SOLVED: To provide a butterfly valve which secures high seal performance while reducing rubber lining portions to the minimum, preventing the wear and damage of a valve seat portion, and suppressing an adverse effect to water quality, can prevent the generation of cavitation, and is easy in manufacturing.SOLUTION: In the butterfly valve rotatably arranged with a disc-shaped valve body 5 in a valve box 2 via a valve rod 3, a winding forming part 10 is arranged in a position outside an external periphery of the valve body 5. An external peripheral groove 11 and a penetration hole 12 penetrating the external peripheral groove 11 are formed at the winding forming part 10, a rubber winding part 15 is formed by integrally winding rubber 8 filled into the external peripheral groove 11 and the penetration hole 12 to an external peripheral face 10a of the winding forming part 10, and an external peripheral portion of the rubber 8 filled into the external peripheral groove 11 is made to function as a water stop valve seat part 20. |
