Which sprinkler system includes both air pressure and detection as part of operation?

Which sprinkler system includes both air pressure and detection as part of operation?

• A. Dry Pipe Sprinkler System
• B. Preaction Sprinkler System
• C. Residential Sprinkler
• D. Alarm Device

Answer: (B)

Preaction sprinkler systems use both air pressure in the piping and a detection-trigger to release water. The pipes are kept under pressure with air (or nitrogen) and stay dry until a detection device—such as a heat or smoke detector—is triggered. When detection occurs, a valve opens and water enters the piping, filling it and releasing water to the sprinklers. This combination of a pressurized, dry system with a detection-initiated water release is what makes this option the best fit.