Fire sprinkler systems have been in use since 1874 and have prevented the catastrophic loss of life and property. Fire sprinkler systems include sprinkler heads that contain glycerin-based liquids. The sprinkler system identifies a fire because of rising temperatures. At temperatures between 135-165⁰F, the glycerin-based liquid inside the bulb expands breaks the glass, and the sprinkler head is activated.
Once the glass bulb breaks, the sprinkler head releases water. The type of sprinkler system you use determines how the water is stored and distributed through pipes. Wet pipe systems store water in the pipes and release the water when the trigger breaks. Dry pipe systems store water behind a valve that needs to be released before the water flows out of the sprinkler head. A pre-action sprinkler is similar to a dry pipe system, except the valve is controlled by an electronic device. There is also a deluge sprinkler system that is not activated by heat, but a fire alarm releases the water, and a valve needs to be manually closed to stop the water flow.