What is a Pre-Action Fire Sprinkler?

Pre-action fire sprinkler systems are one of several different types of fire sprinkler systems, each with advantages and disadvantages. Varying conditions dictate which type of system is optimal.

Function

• A pre-action fire sprinkler system is designed to quickly engage the sprinklers when a fire is detected without having to keep the pipes filled with water at all times. This is done by using a separate fire detector that turns the pipe valves on before the sprinklers detect heat and engage themselves.

Benefits

• Primarily, pre-action fire sprinklers are most advantageous under conditions in which water leakage or false alarms could be particularly damaging, like in fine art galleries or computer labs. They also operate faster than traditional dry sprinkler systems.

Deluge Variation

• The Deluge sprinkler system is a variation of the pre-action fire sprinkler system that keeps the sprinklers open at all times. These are useful in situation where fire spread could be particularly damaging, like in places containing hazardous chemicals or explosives.

On-Off Variation

• The on-off fire sprinkler system is another variation of the pre-action fire sprinkler system, this one with the ability to turn itself off immediately when the fire has subsided. This is done with a thermal detector and cooling device that cools the main control panel when the fire has been extinguished.

Drawbacks

• The biggest deterrent to installing a pre-action fire sprinkler system is the cost of installation and maintenance. They are much more complex than standard fire sprinkler systems, primarily due to the fire detection system implemented, and require regular maintenance.