NFPA 24

Covers — installation of private fire-service mains and appurtenances: underground pipe materials, depth of cover, thrust restraint, valves, hydrants, and flushing/hydrostatic testing supplying fire-protection systems.

Does NOT cover (exclusions) — sprinkler systems → NFPA 13; standpipes → NFPA 14; fire pumps → NFPA 20; public water mains → the water utility/AWWA.

NFPA 24 covers the private buried fire mains between the supply and the building systems.

NFPA 24 sets installation requirements for private fire mains:

• Pipe & Depth — buried pipe materials and required cover.
• Restraint — thrust restraint at bends, tees, and hydrants.
• Valves & Hydrants — isolation valves and hydrant installation.
• Flushing & Testing — flushing to remove debris and hydrostatic/leakage testing.

NFPA 24 governs private fire-service mains — the usually-buried piping, valves, and hydrants on private property that carry water from the supply to the building fire-protection systems. It covers pipe materials, depth of cover, thrust restraint at fittings, valves and hydrants, and the flushing and hydrostatic testing that verify the mains are clean and leak-tight.

It is the link between the public/private water supply and the systems designed to NFPA 13/14, fed as needed by an NFPA 20 fire pump. Because the mains are buried, restraint and testing before backfill are critical.

Engineering Note: Flush the mains thoroughly before connecting to the sprinkler/standpipe systems — construction debris left in a buried fire main can lodge in sprinkler orifices or valves and disable protection at the worst possible moment.