According to NFPA 20, how often must screens on the suction intake of an open-source water supply be inspected for debris?

According to NFPA 20, how often must screens on the suction intake of an open-source water supply be inspected for debris?

• A. Hourly
• B. Daily
• C. Periodically
• D. Monthly

Answer: (C)

Suction-screen debris on open-source water supplies is kept clear through regular preventive maintenance. NFPA 20 treats the inspection of these screens as something that should occur at periodic intervals rather than at a fixed, rigid schedule. The idea is to check the screens often enough to catch and remove debris before it blocks suction, but not so often that it becomes an impractical burden in varying field conditions. If debris is found, clean or replace the screen as needed to maintain proper flow and pump prime. Hourly and daily checks would be unnecessarily frequent for most installations, while a strict monthly interval may not fit all environments. The guidance uses periodic inspection to reflect the varying conditions of open-water sources.

Suction-screen debris on open-source water supplies is kept clear through regular preventive maintenance. NFPA 20 treats the inspection of these screens as something that should occur at periodic intervals rather than at a fixed, rigid schedule. The idea is to check the screens often enough to catch and remove debris before it blocks suction, but not so often that it becomes an impractical burden in varying field conditions. If debris is found, clean or replace the screen as needed to maintain proper flow and pump prime.

Hourly and daily checks would be unnecessarily frequent for most installations, while a strict monthly interval may not fit all environments. The guidance uses periodic inspection to reflect the varying conditions of open-water sources.