摘要 |
A ball valve (10) is described which has a ball valve retaining mechanism which, when subject to very slight movement, allows a ball element (20) to be unloaded off a valve seat (48) during rotation, but remain in contact with the valve seat (48) so as to prevent debris ingress between the ball and the valve seat, and to instantaneously reload onto the valve seat upon the event of closure. This instantaneous and automatic redirection of the reaction load path at the occurrence of closure provides an effective seal against high pressure aggressive fluids to prevent fluid escaping beyond the valve components whilst, at the same time, allowing effective rotational movement of the valve to occur without providing rotational reliability. This solution allows conflicting load paths through the valve to be resolved, namely through the trunnion during rotation and through the valve seat during sealing.
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