The York 022-10642-002 16.65" Butterfly Valve is intended to be used in HVAC systems. More specifically on the valves operating within a pipe, butterfly valves function with the aid of a rotating disc. In this arrangement, the disc lays parallel to the flow when fully open and is perpendicular when in the closed position. Partial rotation also enables the flow to be regulated. Some advantages of this particular valve include enhanced flow regulation which results in the efficiency of the system. It also helps in reducing the pressure drop across the valve which leads to increased energy performance. Also, it can be easily assembled and maintained, which means that it has low time for maintenance in HVAC systems.