What type of sprinkler heads discharges water from all heads simultaneously?

Deluge heads are designed to discharge water from all heads simultaneously when they are activated. This is a critical feature that makes them particularly effective for certain high-hazard applications, such as areas where flammable liquids are stored or in places with a significant risk of rapid fire spread. The deluge system is typically connected to a water supply and only activates when the triggering system (like a fire alarm) signals, allowing all the designated heads to release water at once, thus providing an immediate and comprehensive deluge effect to suppress a fire.

In contrast, fusible-link heads and frangible-bulb heads are types of sprinkler heads that operate based on heat activation, with each head responding independently. Automatic heads activate only in the presence of heat at that specific location, meaning they will discharge water only from those individual heads that have detected heat, rather than from all heads at once. This individual activation helps to contain the fire to a specific area, but does not provide the immediate broad coverage that deluge heads offer.