Which sprinkler system has all heads open and releases water through all heads when the system is activated?

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

Answer: (C)

Deluge sprinkler systems flood the piping with water and keep every head open. When the system is activated, water is released to flow through every sprinkler head at once, providing immediate, full-coverage spraying. This is exactly why it’s chosen for areas where rapid, total sprinkler coverage is needed.

In contrast, other systems keep heads closed until a heat trigger or a valve release occurs, so water doesn’t come out of all heads at once. Wet-pipe has water-filled pipes but each head is individually closed until its heat-sensor activates. Dry-pipe stores air in the pipes and fills them with water only after a trigger, delaying water to the heads. Pre-action requires a secondary event to release water into the pipes before the heads spray.