Which type of valve is required by NFPA 11 for foam suppression systems?

Which type of valve is required by NFPA 11 for foam suppression systems?

• A. Ball valve
• B. Check valve
• C. Indicator type
• D. Gate valve

Answer: (C)

NFPA 11 requires an indicator-type valve in the foam concentrate supply path so you can visually confirm that the concentrate is being delivered and that the valve is in the open or charged position. This indication is crucial for verifying the foam system is actually ready to deploy and for quick diagnosis during testing or operation. Other valve types—ball, gate, or check valves—control flow or prevent backflow, but they don’t provide a built-in visual or mechanical indication of the valve status, so they don’t meet the NFPA 11 requirement.

NFPA 11 requires an indicator-type valve in the foam concentrate supply path so you can visually confirm that the concentrate is being delivered and that the valve is in the open or charged position. This indication is crucial for verifying the foam system is actually ready to deploy and for quick diagnosis during testing or operation. Other valve types—ball, gate, or check valves—control flow or prevent backflow, but they don’t provide a built-in visual or mechanical indication of the valve status, so they don’t meet the NFPA 11 requirement.