Corrosion Protection provides protection for which part of the system?

• A. Above-ground steel frames
• B. Sprinkler heads against heat
• C. Underground pipes against rust
• D. Fittings against leaks

Answer: (C)

Corrosion protection in a low-rise residential sprinkler system is focused on the metal surfaces that are buried in the ground. Underground piping is exposed to soil moisture, minerals, and other conditions that can cause rust and corrosion, so the protection is applied to prevent leaks and failures in those buried pipes. The other components—above-ground steel frames, sprinkler heads, and fittings—aren’t the parts specifically protected by this requirement in NFPA 13R, since they aren’t in contact with soil in the same way. Keeping underground piping from rusting helps ensure the system remains reliable after installation and throughout its service life.