A gas system protects enclosed areas and works by totally flooding the area, with the exception of with CO2 which can protect an object by local application.
Different gas agents can be used :
- inert (IG01, IG100, IG341, IG541, IG55) found in the atmosphere
- carbon dioxide
- inhibitor (chemical gases – HFC227ea, FK 5-1-12, HFC23)
How does it work ?
No matter which type of gas is used, the concentration of the extinguishing agent is maintained above a minimum for the required time. This concentration is variable depending on the risks and nature of the extinguishing agent.
An automatic extinguisher gas system is made of four parts :
- elements for fire detection (fire detection system)
- elements for fire extinction (storage and emission)
- elements for gas diffusion
- elements for evacuation signs
What happens during a fire :
- inert gases and CO2 act by smothering. They decrease oxygen content by around 12% to 13% in general.
- in some cases, CO2 discharge could also help cooling.
- inhibitor gases work to counteract the chemical reaction mechanisms that produce a flame.
When is it used ?
Low or high pressure CO2 :
- gas turbines, engine test benches, alternators, generators, oil cellars, rolling mills, paint/spray booths, electrical rooms, printing : press, rotary printing, archives.
Inert and inhibitor gases :
- electrical rooms, computer rooms, data centers, specific premises in laboratories, archives.