What is OS&Y?

OS&Y stands for Outside Screw and Yoke. This design places the threaded stem outside the valve body, with the yoke supporting the stem. It allows users to visually verify whether the valve is open or closed by observing the stem’s position.

OS&Y gate valves are commonly used in fire protection systems, including sprinklers, hydrants, and standpipes, due to their reliability and clear open/close indication.