On concentric butterfly valve, the stem is centered in the middle of the disc and the disc centered in the bore. A concentric butterfly valve is a flow control device that controls the flowing medium in the system using a rotating disk. The disk remains in the passage, but due to its thinness, it provides little impediment to the flow. Concentric butterfly valves have a relatively simpler design. The valve body, seals, flap, and stem are the main components of a concentric butterfly valve.
