A wafer style butterfly valve is one of the two butterfly valve mounting schemes that Hanna Rubber Company has to offer. The wafer valve is designed to use a rubber seal to create a tight seal and prevent back flow in a system that is designed for unidirectional flow. Wafer valves are cheaper than lug valves and easier to install but once installed the wafer valve cannot be moved. Wafer valves are used to control the flow of substances such as water, chemical services, and ventilation applications.