| 摘要 |
<p>PURPOSE:To improve sealing capability by forming notch portions on both end portions of a passageway of a ball and extending a circular seal portion to the inner peripheral portion of a ball seat, whereby when the passageway of the ball and a passageway of a valve body are aligned with each other, the ball and the valve body are not brought into contact with each other. CONSTITUTION:Notch portions 22 are formed on both end portions of a passageway 21 of a ball 2. A ball seat 3 comprises a circular main body 31 and a seal portion 32 extended from the circular main body 31 inwards a passageway of a valve body 1. Thus, when a passageway 21 of the ball 2 and a passageway of the valve body are aligned with each other, the notch portions are not brought into contact with the seal portion 32. Accordingly, as deformation force is not applied to the ball seat 3 at the time of opening a valve, it is possible to achieve a ball valve which can avoid leakage and has a good sealing capability by using fluororesin or the like excellent in various characteristics, while the ball seat 3 has a small range of elastic deformation.</p> |
