OS&Y gate valve commonly used to control water flow to fire sprinkler systems. OS&Y means “outside stem and yoke” or “outside screw and yoke”. OS&Y gate valves operate by opening and closing via a gate, which lowers into or rises out of the valve. Raising the gate allows water to flow through the valve while lowering the gate cuts off the water flowing through the valve. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low friction loss.
Gate valve belongs to shutter gate. The direction of movement of the gate is perpendicular to the direction of the flow. The gate valve can only be fully opened and fully closed, and it cannot be adjusted or throttled. The gate valve is sealed by the contact between the valve seat and the gate plate.