A type of sprinkler system that, upon fire detection, has a valve that opens and permits water to flow out of all the sprinklers at once is:

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

Answer: (C)

Deluge systems are designed so that when the system is activated, water is released to every sprinkler head at once because all heads are open. This means rapid, wide-area protection since there’s no individual head being held back by a valve or seal.

This differs from wet-pipe systems, where piping is filled with water and water discharges only from the sprinkler head(s) that reach their heat-sensitive trigger. Dry-pipe systems keep the piping filled with air and introduce water into the lines after the system is activated, but the sprinkler heads remain closed until heated. Pre-action systems require a two-step process: a detection event or trigger must occur before water is released into the sprinkler lines.