An automatic fire sprinkler system head is a valve, that when the temperature sensitive bulb reaches its predetermined fixed temperature, expands, breaks and then allows the free flow flow of water.

Sprinkler Head Operation

Fire Sprinkler Head Components

The glass bulb for an automatic fire sprinkler head is the active component that breaks when it reaches its nominal operating temperature.  There are generally two sizes of the glass bulb;

  • 3mm - Quick Response
  • 5mm - Standard Response

Due to thermal conductivity, the thinner (3mm) quick response will respond more quickly to a rise in temperature and operate more quickly than the 5mm standard response.

Fire Sprinkler Head Components


Sprinkler Head Operating Temperatures 

Automatic Fire Sprinkler Bulb Operating Temperatures
Read time: 0 mins