| 摘要 |
<p>A valve (10) comprises a tubular insert (14) defining an inlet duct of given cross-sectional shape. A valve member (40, 42) is arranged to rotate about an axis. The valve member (40, 42) is formed with a recess (44, 46) extending from a position adjacent its access of rotation, which recess (44, 46) in a first rotational position of the valve member (40, 42) is spaced from a surface to define a passage through which fluid can pass from the inlet duct (15). The valve member (40, 42) is rotatable from the first rotational position towards a second rotational position whereby an edge (44a, 46a) of the recess reduces the cross-sectional area of the passage. The inlet duct (15) has a wall section (36, 38) which terminates at a position adjacent the recess (44, 46) and the axis of rotation of the valve member.</p> |
