| 摘要 |
PURPOSE:To prevent foreign matter from entering into a butterfly valve device to restrain the affection by stream disturbance upon slight opening of an upper valve, by disposing two butterfly valves for a steam turbine in series, and by disposing a frusto-conical shape strainer having a rectifying and reinforcing rib between the butterfly valves. CONSTITUTION:Two butterfly valves 1, 2 are disposed in a steam pipe line 3 in series, and a strainer is disposed between the valves 1, 2. The strainer is in a frusto-conical shape having a rectifying and reinforcing rib 22. With this arrangement, it is possible to restrain the affection upon the downstream valve 2 by stream disturbance generated upon slight-opening of the upstream valve 1. |
