How does a fire sprinkler system work?

A typical fire sprinkler system contains two main components: the sprinkler heads and the piping. The heads are usually installed on ceilings, and they connect to a network of pipes. The pipes either connect to a water main or storage tank via a valve, or are kept filled with water.

The sprinkler heads are either fitted with a glass bulb containing heat-sensitive liquids or gases, or with a fusible link sealed with a material that melts at a certain temperature. The moment a fire starts, it sends a burst of heat toward the ceiling. The heat either expands the contents of the bulb, breaking the glass, or melts the seals on the fusible links. This forces water through the sprinkler heads, dousing the fire.

A fire sprinkler system releases droplets big enough to penetrate the centre of the fire without evaporating--the amount of flow-through, water pressure, and size of the droplets are strictly controlled. This lowers the temperature at the fire's core--enough that it can't maintain the heat it needs, and goes out.

A fire sprinkler system is more effective than a brigade of firefighters--at least initially. That's because while it can take the fire department valuable minutes--sometimes even longer--to respond to an alarm, a fire sprinkler system can respond in seconds, putting the fire out before it has a chance to spread.

For more information about fire sprinkler systems visit NFPA.org .