| 摘要 |
<p>A ball valve is provided in which the outer housing (1) can be left in a pipeline during servicing and a sub-assembly can be removed as a unit from the top of the outer housing (1). The sub-assembly comprises an inner housing (8) in which a ball member (17) is journalled for rotation, and annular adaptors (13) for interposition between the ball member (17) and diametrically opposite openings (3) in the outer housing (1). The adaptors (13) are such that they can be easily withdrawn outwardly from the withdrawn sub-assembly to reveal the ball member (17) for inspection without having to remove the ball member (17) itself. The adaptors (13) are also wedge-shaped so that when the sub-assembly is refitted in the outer housing (1) the adaptors (13) automatically come into sealing engagement with the ball member (17) and the outer housing (1).</p> |
