Which could be used as a control valve for an automatic sprinkler system?

Which could be used as a control valve for an automatic sprinkler system?

• A. Outside-stem and yoke valve
• B. Gate valve
• C. Ball valve
• D. Globe valve

Answer: (A)

The main skill this question tests is the ability to select a control valve whose position can be observed easily from outside the valve. For an automatic sprinkler system, it’s crucial to know at a glance whether the main shutoff is open or closed, especially during inspections or emergencies. An outside-stem and yoke valve provides a rising stem that moves with the valve and remains visible above the valve body. When the valve is opened, the stem rises, giving a direct, unmistakable indication of its position, so personnel can confirm the valve status without disassembling or guessing. This clear visual feedback is why this type of valve is preferred for control applications in sprinkler systems. Other valve types can function as isolation valves, but they don’t inherently offer the same readily observable position indicator. Gate valves and globe valves may not clearly show whether they’re fully open or fully closed from a distance, and ball valves, while quick to operate, don’t reliably provide the same level of visual confirmation and are less commonly chosen as the main control valve for larger sprinkler mains.

The main skill this question tests is the ability to select a control valve whose position can be observed easily from outside the valve. For an automatic sprinkler system, it’s crucial to know at a glance whether the main shutoff is open or closed, especially during inspections or emergencies. An outside-stem and yoke valve provides a rising stem that moves with the valve and remains visible above the valve body. When the valve is opened, the stem rises, giving a direct, unmistakable indication of its position, so personnel can confirm the valve status without disassembling or guessing. This clear visual feedback is why this type of valve is preferred for control applications in sprinkler systems.

Other valve types can function as isolation valves, but they don’t inherently offer the same readily observable position indicator. Gate valves and globe valves may not clearly show whether they’re fully open or fully closed from a distance, and ball valves, while quick to operate, don’t reliably provide the same level of visual confirmation and are less commonly chosen as the main control valve for larger sprinkler mains.