BUTTERFLY VALVE ASSEMBLY WITH IMPROVED FLOW CHARACTERISTICS

摘要

A control valve assembly that utilizes a butterfly valve having a valve body and a valve disc movable between a seated position and an open position. The contr ol valve assembly includes a flow insert positioned along the interior of the valve body and generally aligned with a first outer sealing edge of the rotatable valve dis c. The flow insert maintains close spacing to the first outer sealing edge of the valve disc as the valve disc initially moves away from the valve seat. The control valve assembly can also include a first, upstream butterfly cage and a second, downstream butterfly cage positioned on opposite sides of the valve body. The first and second butterf ly cages aid in controlling the flow of fluid past the valve disc as the valve disc moves from its seated position to its open position.