| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of a noise when a ball valve is opened. SOLUTION: While a ball valve 17 is provided rotatively between the inlet 12 and the outlet 13 of a valve main body 11, a different pressure control mechanism 21 to control the different pressure at the front part and the rear part of the ball valve 17 at a limit value is provided in the upstream from the ball valve 17. By controlling the different pressure on the front side and the rear side of the ball valve 17 by the different pressure control mechanism 21, a severe turbulance generated by the ball valve 17 is prevented, and the generation of a noise by the turbulance is suppressed.
|
