Which of the following is NOT one of the common types of automatic water-based sprinkler systems?

The common types of automatic water-based sprinkler systems include wet pipe, dry pipe, and preaction systems. Each of these designs serves a specific purpose in fire protection.

A wet pipe system contains water in the pipes at all times, allowing for immediate discharge of water when the heat from a fire activates the sprinkler head. This system is well-suited for areas where the pipes will not freeze.

A dry pipe system, on the other hand, is filled with pressurized air or nitrogen, and water is held back by a valve. When a sprinkler head is activated, the air pressure drops, allowing the valve to open and water to flow. This system is typically used in areas subject to freezing temperatures.

A preaction system combines elements of both wet and dry systems. In this design, water is not in the pipes until an initial detection system senses a fire. When the detection is triggered, the valve opens, and water fills the pipes, allowing droplets to discharge upon activation of any sprinkler head.

The term "delayed activation" does not represent a recognized common type of sprinkler system. While some systems may feature a delay mechanism to minimize false alarms or unwanted discharges, this is not categorized as a separate class of automatic water-based sprinkler systems. By