US Patent 9611947 Valve assembly and method of controlling flow of fluid

A valve assembly includes a plenum having first, second, and third air source ports, a flapper valve assembly pivotally movable between a first position, where the first air source port is closed by the flapper valve assembly and the second and third air source ports are open and in fluid communication, and a second position, where the second air source port is closed by the flapper valve assembly and the first and third air source ports are open and in fluid communication and a method of controlling fluid flow via a valve assembly.