A control valve includes a first conduit having a first inlet and a first outlet and defining a first passage; a second conduit having a second inlet and a second outlet and defining a second passage, the second conduit extending into the first passage such that the second inlet is located within the first passage; and a valve plate disposed pivotably within the first passage, the valve plate defining a valve plate surface. Pivoting of the valve plate within the first passage varies flow from the first inlet to the first outlet and the valve plate is pivotal between a first position and a second position such that in the first position the valve plate substantially prevents fluid communication between the first passage and the second passage and such that in the second position the valve plate permits fluid communication between the first passage and the second passage.
1. A control valve comprising:
a first fluid conduit having a first fluid conduit inlet and a first fluid conduit outlet, said first fluid conduit defining a first fluid passage from said first fluid conduit inlet to said first fluid conduit outlet;
a second fluid conduit having a second fluid conduit inlet and a second fluid conduit outlet, said second fluid conduit extending into said first fluid passage such that said second fluid conduit inlet is located within said first fluid passage, and said second fluid conduit defining a second fluid passage extending from said second fluid conduit inlet to said second fluid conduit outlet; and
a valve plate disposed pivotably within said first fluid passage between said first fluid conduit inlet and said first fluid conduit outlet, said valve plate defining a valve plate surface;
wherein pivoting of said valve plate within said first fluid passage varies flow from said first fluid conduit inlet to said first fluid conduit outlet; and
wherein said valve plate is pivotal between a first position and a second position such that in said first position said valve plate surface covers said second fluid conduit inlet, thereby substantially preventing fluid communication between said first fluid passage and said second fluid passage and such that in said second position said valve plate surface does not cover said second fluid conduit inlet, thereby permitting fluid communication between said first fluid passage and said second fluid passage;
wherein said valve plate is configured to block said first fluid passage when said valve plate is pivoted to said first position, thereby substantially preventing fluid communication between said first fluid conduit inlet and said first fluid conduit outlet; and
wherein said valve plate is configured to block said first fluid passage when said valve plate is pivoted to said second position, thereby substantially preventing fluid communication between said first fluid conduit inlet and said first fluid conduit outlet.
2. A control valve as in claim 1 wherein:
said valve plate is pivotal to a third position in which said valve plate permits fluid communication between said first fluid conduit inlet and said first fluid conduit outlet and also permits fluid communication between said first fluid passage and said second fluid passage.