How do fire sprinklers work?

People often ask how fire sprinklers work, usually their only education has been what they have seen in the movies so i thought i would write this short article to help educate those who wish to know.

Firstly, when a fire has started the heat and smoke rise upwards. When this heat and smoke hit the ceiling it spreads across the ceiling causing what is commonly known as a ceiling jet.
Fire sprinkler heads are positioned either on the ceiling or high up on the walls of a room . They act as plugs for the water in the pipe work, the pipe work connects all the heads to the water supply. Fire sprinkler heads have either a glass vile filled with gases and liquid that expands under a specific heat or a fusible link that melts upon contact with a specific heat, the heat required varies depending on which type of head is used but generally around 70c.
When the heat around an individual sprinkler head reaches 70c it will actuate releasing the water over the area consumed by the fire, not every sprinkler head will start. Smoke cannot start fire sprinklers releasing water either.
Depending on what water supply is used it will either keep running ( system attached to the water main) or run until the tank runs dry (pump and tank system).
After the fire has been put out and the building is considered safe the used sprinkler head/s can be easily replaced and the system re-commissioned by a qualified installer.



Check out the video at the bottom of the page for a graphic explanation.