Which sprinkler system is most commonly used in buildings?

• A. Deluge
• B. Dry-pipe
• C. Wet-pipe
• D. Pre-action

Answer: (C)

The main idea here is recognizing which sprinkler system is most commonly installed in typical buildings. Wet-pipe systems are filled with water in the pipes and have sprinkler heads that release immediately when a head is activated. This simple, direct design makes them reliable, easier to maintain, and cost-effective, which is why they’re the standard choice for most buildings.

Other systems have special features for specific needs: a deluge system releases water through all heads once triggered, useful in high-hazard areas but not common for everyday occupancy; a dry-pipe system keeps pipes pressurized with air or nitrogen to prevent freezing and delays water delivery, so it’s pricier and used in colder climates or where freezing is a concern; pre-action systems require a two-step process before water is released, reducing accidental discharge but adding complexity and cost for protecting high-value contents.

So, the most common choice for buildings is the wet-pipe system because of its simplicity, immediacy, and lower cost.