Check Valves prevent backflow by automatically closing when fluid reverses direction. Wafer checks may be installed in horizontal positions (or vertical with flow moving up). Please refer to NIBCO® technical data sheets, chemical resistance guides and catalogs for engineering and installation information. Choose NIBCO® Check Valves for the most specified, versatile and economical valve option in commercial, mechanical and industrial applications. NIBCO® Check Valves are backed by the NIBCO® 5 years 125% limited warranty.