Fire Sprinkler Systems
A fire sprinkler system is on duty 24 hours a day, 7 days a week, silently protecting you.
As the ambient temperature rises due to a fire below a specific sprinkler, liquid in a glass vessel within the sprinkler head expands increasing the pressure within the vessel.
At a temperature predetermined during the design process, the vessel bursts, releasing pressurised water from the system which is sprayed at a predetermined rate across a specific area, extinguishing the fire.
Fire sprinkler systems protect people, property and product automatically.
In buildings fully protected by sprinklers:
- 99% of fires are controlled by sprinklers alone
- 60% of fires are controlled by the spray from no more than 4 sprinklers
There are many different types of sprinkler systems:
Dry
The most common type, where the pipes in the system are kept full of water, used when there is no risk of freezing.
Wet
The pipes are always kept full of air under pressure, a control valve holds the water back. A drop-in air pressure due to a sprinkler valve opening causes the control valve to open, water fills the pipe system and is sprayed onto the fire. Used in unheated buildings where there is a risk of freezing.
Alternate
Systems that are kept full of water in summer then drained and filled with pressurised air in winter.
Pre-action
As in dry systems, the pipes are kept full of air, but the valve holding the water from entering the system is controlled by a fire detector such as a smoke detector.
Foam enhanced
These types discharge a mix of water and low expansion foam concentrate, resulting in a foam spray from the sprinkler. Foam is more effective than water in extinguishing fires involving flammable gases or flammable liquids and chemicals.
Deluge
This type differs in that all the sprinklers within the system are open, so that water is sprayed from all valves when the system is activated. The water is held back by a deluge valve, activated by a fire detection sensor, which could be smoke, heat, or optical flame detector. Used when there are special hazards, such as where the rapid-fire spread is a risk.
