| 摘要 |
<p>A dual in-line ball valve assembly for a subsea tree intervention tool has a pair of axially-movable pistons and a rotatable linkage member pinned between each of the pistons and the independently operable ball valves. The linkage members have eccentric hubs which rotate the ball valves between open and closed positions when the pistons are axially actuated. A recess is formed in each ball valve adjacent to the central flow passage of the assembly for accommodating a lower side of tubing or wireline. The recesses prevent shearing of the tubing or wireline in two places when one of the valves moves to the closed position.</p> |
