Which sprinkler system is designed to protect extra hazardous occupancies with all sprinkler heads constantly open?

The deluge system is specifically designed to protect extra hazardous occupancies by having all of its sprinkler heads open simultaneously. This type of system can deliver a large volume of water rapidly to suppress fires in environments that pose a significant risk due to the materials present. Since there are constant open heads, the deluge system is particularly useful in scenarios where a rapid and overwhelming response is needed, such as in industrial settings or facilities storing flammable substances.

In contrast, the wet pipe system contains water at the sprinkler heads and only activates when a fire is detected. The pre-action system combines elements of both wet and dry pipe systems and typically includes a detection system that must activate before water is released, making it less immediate in response than a deluge system. Lastly, the dry pipe system holds pressurized air in the pipes, which upon activation by heat or smoke, releases the air, allowing water to flow into the system. This system is primarily used in locations prone to freezing temperatures, not necessarily for high-hazard areas.