| 摘要 |
PURPOSE:To perform both general flow control and small flow control, by equipping a means which opens and closes a water flow port drilled in the main valve unit of a butterfly valve by vertically moving a valve rod. CONSTITUTION:If a threaded part 11 is lifted upward by operating a handle 15, a valve rod 4 is also lifted enabling a water flow port 3 to be set to an opening condition. In this way, a butterfly valve, allowing water in a valve case 1 to flow in the water flow port 3, releases a small amount of water to a valve case 1 in an opposite side. Next if an operating handle 8 is turned, its turning effect is transmitted to a valve unit 2 through a worm gear 6 and the valve rod 4. Accordingly, the butterfly valve, gradually opening the valve unit 2 from its closing condition, enables a large amount of water to be released. |
