What type of valve is used where the valve is not buried and an operator will need to know from an inspection whether the valve is open or closed?

• A. Outside Screw and Yoke (OS&Y) valve
• B. Gate valve
• C. Globe valve
• D. Ball valve

Answer: (A)

The main idea is having a visible indication of valve position for valves that sit above ground. Outside Screw and Yoke means the stem is exposed and moves up as the valve opens. Because the stem is outside the bonnet, you can see it rise or drop, so you can tell at a glance whether the valve is open or closed just by inspecting it. This is especially important for valves that aren’t buried, where quick visual confirmation is needed. Other valve types may not provide a clear external indicator of position, since their stems can be inside the bonnet or the handle position doesn’t always map directly to open/closed status.