What is a primary feature of a "deluge" sprinkler system?

A primary feature of a deluge sprinkler system is that all spray heads open simultaneously. This design is crucial for deluge systems, which are typically used in high-hazard environments where rapid fire spread is a concern, such as in the protection of flammable liquids or materials. When a fire is detected, the deluge system releases water from all of its nozzles, creating a large volume of water to suppress the fire effectively.

This simultaneous activation is different from other sprinkler systems, such as wet pipe systems, where individual sprinkler heads activate based on heat detection. The activation of all heads at once allows for extensive coverage and can quickly cool the area, suppress flames, and help prevent fire spread.

The other options do not accurately capture the essence of a deluge sprinkler system. For instance, while deluge systems do not operate automatically in the traditional sense (like a closed-head system where individual heads react), they are typically activated through a fire alarm or detection system that initiates the flow of water to all heads. A closed nozzle design is characteristic of various other systems, but deluge systems feature open nozzles to allow for simultaneous discharge. Lastly, deluge systems are predominantly employed in commercial and industrial applications due to their effectiveness in handling severe