General The resilient wedge, ductile iron gate valve features Class 125 flanged, flat 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. This valve features a pre-grooved stem for tamper switch mounting and is drilled, tapped, and plugged at location “A” for bypass. It is listed by Underwriters Laboratories of the US and Canada (UL/ULC) and FM