Fire sprinklers are a fire safety system that is tied into a network of pipes containing water under pressure that will release a spray of water when a fire is detected. They utilize a device that contains a fusible substance such as Wood’s Metal, some kind of substance that will melt or which activates them when they reach a certain temperature.

These are either a fusible substance, such as Wood's Metal, a substance that will reliably melt, or a glass bulb that contains a liquid that will burst the bulb when heated to the operating point. Once activated, the pressure of the water will push a plug and allow water to flow freely through the sprinkler.

Each sprinkler in a system is activated individually so as to suppress or extinguish the fire without causing any unnecessary water damage to any unaffected areas. There are sprinkler systems know as open orifice sprinklers which are identical to normal systems; however, the heat sensitive mechanism is removed and fire detection is left to an outside source.