The NIBCO® ductile iron butterfly valve is designed specifically to meet the rigorous requirements of automatic sprinkler systems. The EPDM encapsulated ductile iron disc provides bubble-tight shutoff at rated pressure. With the internal splined stem/disc 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 andmore catalogs for engineering and installation information. Choose NIBCO® ductile iron butterfly valves for the most specified, versatile and economical valve option in commercial, mechanical and fire protection systems. NIBCO® butterfly valves are backed by the NIBCO 5-year 125% limited warranty. less