What is the hydrostatic test interval for CO2 high-pressure cylinders per NFPA 12 2018?

What is the hydrostatic test interval for CO2 high-pressure cylinders per NFPA 12 2018?

• A. 7 years
• B. 3 years
• C. 5 years
• D. 1 year

Answer: (C)

A main safety measure for high‑pressure CO2 cylinders is periodic hydrostatic requalification to verify the vessel can safely withstand pressure over time. NFPA 12 2018 sets this interval at five years for CO2 high‑pressure cylinders used in fixed fire suppression systems. The hydrostatic test involves filling the cylinder with water and pressurizing it to a level higher than its service pressure to check for leaks, distortion, or wall thinning. If the cylinder passes, it’s requalified to continue service for another five years. This five‑year cycle strikes a balance between safety and practical maintenance. Intervals like one, three, or seven years aren’t the standard for this application in NFPA 12 2018.

A main safety measure for high‑pressure CO2 cylinders is periodic hydrostatic requalification to verify the vessel can safely withstand pressure over time. NFPA 12 2018 sets this interval at five years for CO2 high‑pressure cylinders used in fixed fire suppression systems. The hydrostatic test involves filling the cylinder with water and pressurizing it to a level higher than its service pressure to check for leaks, distortion, or wall thinning. If the cylinder passes, it’s requalified to continue service for another five years. This five‑year cycle strikes a balance between safety and practical maintenance. Intervals like one, three, or seven years aren’t the standard for this application in NFPA 12 2018.