The butterfly valve controls the flow of fluid through the conduit by a single valve disc mounted on the central shaft. The disc creates a variable orifice (see Figure 1). Butterfly valves can generally be divided into three basic types: damping valves, elastomeric seat valves, and high-performance valves. Damping valve The damper butterfly valve is actually a butterfly valve without a valve seat (see Figure 2). The valve disc in the valve does not touch the inner wall of the valve body. It does not cut off the fluid; it only decelerates the fluid in the pipe or flue because there is a gap between the outer diameter of the…