Multipurpose piping systems shall be designed and installed in accordance with which standard?

• A. NFPA 13
• B. NFPA 70
• C. IBC
• D. NFPA 13D

Answer: (D)

Multipurpose piping in residential sprinkler design is governed by NFPA 13D. This standard covers sprinklers installed in one- and two-family dwellings and manufactured homes and explicitly allows the same piping system to serve both domestic water use and the fire sprinkler system, which is why it’s the appropriate reference for these setups. In contrast, NFPA 13 applies to larger or non-residential systems and typically requires dedicated sprinkler piping separate from the domestic water supply; NFPA 70 is the electrical code; and the IBC is a broad building code, not a sprinkler-specific design standard. NFPA 13D also includes requirements such as backflow protection to safeguard the potable water supply and ensure the system functions correctly within residential conditions.