| 摘要 |
PURPOSE:To easily achieve primary sealing of a butterfly valve by forming an annular projection made of a sealing material around a valve rod of a butterfly valve member and a circumferential projection of a sealing material extending along the outer periphery of the valve member in connection with the above projection. CONSTITUTION:A butterfly valve member 10 is covered on the outer peripheral surface thereof with a sealing material 11. An annular projection 13 of the sealing material 11 is formed around a valve rod 12 of the valve member 10, and a circumferential projection 14 is formed around the outer periphery of the valve member in connection with the projection 13. Both of the projections 13, 14 are determined to have the same height, so that positive sealing is obtained around the valve rod either on opening or closing of the valve, preventing leakage of fluid through the valve rod portion. |
