What is a pre-action system?

What is a pre-action system?

• A. A system that requires an initial event or detection trigger before water enters the pipes
• B. A system that fills piping automatically upon power loss
• C. A system that has no water in pipes unless physically activated
• D. A standard dry-pipe system

Answer: (A)

Pre-action systems require a triggering event before water enters the piping. The piping is kept dry (or only partially pressurized), and water is stored in a separate reservoir. An initial detection event—such as a heat or smoke detector—or a manual release must occur to release water into the piping. Only after that trigger is the system ready for the sprinklers to release water when they heat up, meaning water won’t flow simply because a sprinkler head is activated. This two-step approach protects areas with valuable or sensitive contents from accidental water damage.

Pre-action systems require a triggering event before water enters the piping. The piping is kept dry (or only partially pressurized), and water is stored in a separate reservoir. An initial detection event—such as a heat or smoke detector—or a manual release must occur to release water into the piping. Only after that trigger is the system ready for the sprinklers to release water when they heat up, meaning water won’t flow simply because a sprinkler head is activated. This two-step approach protects areas with valuable or sensitive contents from accidental water damage.