The NIBCO? ductile iron gate valve provides full flow with minimal pressure drop. With its ductility, the valve displays higher physical properties than standard grey cast iron. The alloy iron gate valve features PN25 face end connections for easy installation and accessibility. Outside screw and yoke (OS&Y) gate valves are recommended when positive shutoff and a quick visual indicator of open/closed position is required. The OS&Y configuration protects the stem threads from contact with the media.