The hydrostatic test interval for a wet chemical extinguisher is in how many years?

• A. In 6 years
• B. In 12 years
• C. Every 3 years
• D. In 9 years

Answer: (B)

Hydrostatic testing checks the container’s ability to safely hold pressure by pairing a test liquid with a high-pressure load to reveal any hidden flaws in the cylinder. For wet chemical extinguishers, which are Class K units used in commercial kitchens, the standard requires this test every 12 years. That 12-year interval reflects the robust cylinder design and materials used for these extinguishers, as established by NFPA 10. After the test, the extinguisher is recharged and a new service date is recorded, ensuring it remains ready for use.

The other intervals don’t align with how wet chemical extinguishers are scheduled to be tested under standard practice; they pertain to different extinguisher types or maintenance timelines.