For systems protecting occupiable spaces with high design concentrations, which item is included as a requirement?

• A. Heat detectors
• B. Supervised system lockout valves
• C. Visual alarms
• D. Manual pull stations

Answer: (B)

In spaces protected by high design concentrations, the release of a clean agent must be controlled and verified to prevent accidental or unauthorized discharge. The way this is achieved is by using system components that are continuously monitored for proper operation, specifically supervised system lockout valves. These valves are wired so their position is continuously supervised and reported to the control system. If a valve is not in the correct state or if its supervision circuit detects a fault, the system will alert and, importantly, can prevent release until the issue is resolved. This level of oversight reduces the risk of unintended discharge in a space where a high agent concentration could pose serious hazards to occupants.

Other elements, like heat detectors, visual alarms, or manual pull stations, are common and important for detection and notification, but they do not constitute the specific control requirement emphasized for high design concentration spaces—the ongoing supervision of the release valves themselves ensures intentional, verifiable actuation.