| 摘要 |
<p>A valve assembly (10) for use controlling flow of fluid into a drill pipe (42), the valve assembly (10) having a valve body (12), a valve member (20) and a valve seat (14), wherein a) the valve body (12) has a main passage b) the valve member (20) is movable between a closed position in which the valve member (20) engages with a seat face (16) of the valve seat (14) to substantially prevent flow of fluid along the main passage, and an open position in which the valve member (20) is spaced from the seat face (16), c) the valve seat (14) is a separate part to the valve body (12).</p> |
