The NIBCO® ductile iron butterfly valve features a unique molded-in Buna-N seat liner with aluminum bronze disc, recommended for most water applications. With the internal stem/disc geometric drive design there is no need for pins or bolts that may create leak paths or turbulence in the waterway. An extended neck allows for insulation up to 2 inches. Please refer to NIBCO technical data sheets, chemical resistance guides and catalogs for engineering and installation information. Choose NIBCO® butterfly valves for the most specified, versatile and economical valve option in commercial, mechanical and industrial applications. NIBCO® butterfly valves are backed by the NIBCO 5-year 125% limited warranty.