| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize quick flow start after opening operation by an operational part and a wide fluid control range by the same operational part and also improve fluid control accuracy in a ball valve. SOLUTION: In the present ball valve 10, an opening on the inflow side of the flow through hole 13 of a ball 12 is defined as a main opening 14 and an auxiliary opening 14a and an opening on the outflow side is defined as a fan-shape opening 15. In this case, when the valve is fully closed, the tip end part 15A of the fan-shape opening 15 is set to the first seal region 17A by the outflow side seal member very close to the outlet flow route, and also when the valve is fully opened, the tip end part 15A of the fan-shape opening 15 is so set as invading the second seal region 17B by the outflow side seal member across the outlet flow route.</p> |
