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. 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 splined stem/disc drive design there is no need for pins or bolts that maymore create leak paths or turbulence in the waterway Please refer to NIBCO technical data sheets, chemical resistance guides and 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