Which valves are used to open and close the water supply in large facilities?

Which valves are used to open and close the water supply in large facilities?

• A. Post Indicator
• B. Gate
• C. Ball
• D. Check

Answer: (A)

Shutting off a water supply in large facilities needs a valve that can be operated from the surface and clearly shows whether the line is open or closed. A post-indicator valve does exactly that: it pairs a buried shutoff with a visible indicator post. When the valve is opened or closed, a mechanical linkage moves an indicator on the post so operators can tell the status at a glance without digging. This makes rapid, reliable isolation of large underground mains practical in big facilities, where long runs of pipe and the need for quick action are common. Other valve types can open and close flow, but they don’t provide the same surface-visible status for buried lines. Check valves don’t serve to open/close the water supply at all—they prevent backflow. Ball and gate valves can control flow, but they typically don’t offer the readily visible, surface-accessible indication that post-indicator valves provide, which is crucial in large-scale water systems.

Shutting off a water supply in large facilities needs a valve that can be operated from the surface and clearly shows whether the line is open or closed. A post-indicator valve does exactly that: it pairs a buried shutoff with a visible indicator post. When the valve is opened or closed, a mechanical linkage moves an indicator on the post so operators can tell the status at a glance without digging. This makes rapid, reliable isolation of large underground mains practical in big facilities, where long runs of pipe and the need for quick action are common.

Other valve types can open and close flow, but they don’t provide the same surface-visible status for buried lines. Check valves don’t serve to open/close the water supply at all—they prevent backflow. Ball and gate valves can control flow, but they typically don’t offer the readily visible, surface-accessible indication that post-indicator valves provide, which is crucial in large-scale water systems.