摘要 |
<p>The invention comprises a rotary valve having first and second inlet/outlet flow passages, as well as one or more (preferably between 6 and 8) flow ports. The valve has a plurality of positions simultaneously interconnecting the first and second flow passage to selected flow ports. In a preferred embodiment, the valve has a housing and the flow ports are disposed on outer peripheral walls of the housing. The valve may further include an internal rotary plug that is rotatable about a longitudinal axis to move between the positions, and containing openings to connect the flow passages to the flow ports. The plug may be divided into two chambers in the valve which may or may not be moved independently of each other. The valve may further include a movable seal between the housing and the internal plug member which is retractable to permit freer movement of the plug.</p> |