The NIBCO® ductile iron butterfly valve is designed specifically to meet the rigorous requirements of automatic sprinkler systems. The unique EPDM molded-in seat liner with ductile iron disc provides bubble-tight shutoff at rated pressure. These valves are installed and monitored in fire protection applications where they remain in the normally closed position. A typical application would be fire pump test bypass lines. With the internal stem/disc geometric drive design there is no need formore 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 fire protection systems. NIBCO® butterfly valves are backed by the NIBCO 5-year 125% limited warranty. less