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. Drain valve
• B. Outside-stem and yoke valve
• C. Check valve
• D. Stop or cock valve

Answer: (B)

The main idea is choosing a valve that serves as the primary shutoff for an automatic sprinkler system and clearly shows its position. An outside-stem and yoke valve fits this role because it’s a full-opening shutoff designed for sprinkler systems, and its rising stem is visible from outside the piping. That visible indication makes it easy for inspectors and operators to know whether the valve is open or closed, which is essential for safe maintenance and testing. It’s also readily padlockable and lockout-friendly, helping prevent unauthorized operation. Drain valves are for draining water from sections of the line, not for controlling the flow to the system. Check valves prevent reverse flow but don’t provide a means to shut the system off. Stop or cock valves are general shutoffs, but they typically don’t offer the same reliable, positive position indication and rugged design favored for the main control valve in sprinkler systems.

The main idea is choosing a valve that serves as the primary shutoff for an automatic sprinkler system and clearly shows its position. An outside-stem and yoke valve fits this role because it’s a full-opening shutoff designed for sprinkler systems, and its rising stem is visible from outside the piping. That visible indication makes it easy for inspectors and operators to know whether the valve is open or closed, which is essential for safe maintenance and testing. It’s also readily padlockable and lockout-friendly, helping prevent unauthorized operation.

Drain valves are for draining water from sections of the line, not for controlling the flow to the system. Check valves prevent reverse flow but don’t provide a means to shut the system off. Stop or cock valves are general shutoffs, but they typically don’t offer the same reliable, positive position indication and rugged design favored for the main control valve in sprinkler systems.