Examples of Indicating Control Valves
Outside Stem and Yoke Valve
The outside stem and yoke valve is the most common type of indicating valve. The valve operates by raising and lowering a gate that cuts off the water flowing through the valve casing. The gate connects to a large brass threaded stem with a circular threaded handle that connects to the yoke. As the operator rotates the handle counterclockwise, the stem extends further and further out of the handle, indicating the relative degree of the gate opening. As the operator rotates the handle clockwise, the threaded stem moves back into the valve and presents a lower profile. When the stem is no longer protruding beyond the handle, the gate valve is closed.
Outside stem and yoke valve in open position
Outside stem and yoke valve in closed position
Post Indicator Valve
Located outside a building, the post indicator valve extends up from the ground over a water supply main. As a detachable hand crank operates the valve, a tag connected to the stem reveals the word “open” or “shut” in a window on the side of the valve housing. You can lock the hand crank and the valve itself in position using a padlock or chain.
Post indicator valve in open position
Wall Post Indicator Valve
The wall post indicator valve operates the same way as the post indicator valve, but it extends through the exterior wall of the building and is mounted horizontally. A wheel operates the valve, and you can see its status by the word “open” or “shut” as read through a window in the valve stem housing.
Wall post indicator valve in open position
Wall post indicator valve not maintained
The butterfly valve is hand-cranked open or shut by rotating a disc through the water stream perpendicular or parallel to the water flow. On top of the valve is a “tattle tail” that moves with the disc to indicate the position of the disc relative to the water flow. When the flag lines up parallel to the pipe, the valve opens fully. When it's perpendicular to the pipe, the valve closes fully.
Butterfly valve in open position
Butterfly valve in closed position