What mechanism do frangible bulb sprinkler heads utilize?

Frangible bulb sprinkler heads utilize a glass bulb filled with glycerin or alcohol as their activation mechanism. When exposed to heat from a fire, the liquid inside the bulb expands. This expansion exerts pressure on the glass, which eventually causes the bulb to break. Once the bulb breaks, it releases the water from the sprinkler system, allowing for effective fire suppression in the surrounding area.

This type of sprinkler head is designed to activate at a specific temperature, making it an important component in automatic sprinkler systems. The use of a frangible bulb allows for precise activation, which ensures that water is released only when necessary, reducing water damage and improving overall fire-fighting efficiency.