Fire consists of three essential elements:

1. Combustible Material
2. Sufficient Oxygen
3. Sufficient Heat for Ignition and Continued Burning 

Without any one of these three elements, a fire cannot exist. Removing one or more of these three elements is the basic premise behind fire suppression systems.  Water for example extracts the heat from a fire. Foam also extracts heat and / or keeps away the oxygen. Dry chemical powder interrupts the chain reaction within the flames. Extinguishing gases either displace the oxygen or react in a way to interrupt the chain reaction within the flames (depending on the type of gas).

There are three main types of fire suppression systems:

1. Fire sprinkler systems (wet, dry, pre-action, and deluge)
2. Foam fire systems
3. Waterless fire systems

Fire Sprinkler Systems
A water fire extinguishing sprinkler system is an automatic fire extinguishing or suppressing system. It consists of a secured water supply, valves, pipes (containing pressurized extinguishing agent) and sprinklers. The sprinkler heads are strategically distributed at the ceiling or other endangered places within rooms or areas which shall be protected.

The sprinklers contain a seal. These sealing elements prevent water flow until, due to fire, a design temperature is exceeded at one or more individual sprinkler heads and the sprinkler bulb bursts. Each sprinkler activates independently when the predetermined heat level is reached and distributes the water over the fire source. Since each sprinkler is independently sealed, the system only activates where the fire occurs. The sensor in the system detects the flow of water and emits an alarm signal.

Dry pipe sprinkler systems are initially filled with compressed air above the valve station. The alarm valve opens and releases water in the pipe system in case of a pressure drop due to a sprinkler head opening. This type of system is applicable for areas with frost hazard, or permanent temperatures near to or below 32∞F.

Preaction sprinkler systems - a dry pipe sprinkler system, where two actions are required to open the valve station and herewith the water way; one action is a water lock release triggered by a separate electronic detection system, the other action is the selective sprinkler release at design temperature caused by fire; these systems are for applications that are sensitive to water damage.

Fast-release dry pipe sprinkler systems have characteristics similar to the preaction systems, but provide a faster water discharge.

Water deluge systems (Water Spray Systems) contain open nozzles (instead of sealed sprinklers) strategically distributed with a pipe system connected to an alarm valve, which controls the water supply, so water is discharged over the whole protected area simultaneously. The alarm valve must be actuated by separate means, either manually or via a detection system.

Foam Fire Systems
Foam is mostly produced with water, special detergents and air (air foam), but can also be generated in a chemical way (chemical foam). A system consists generally of a water supply, a tank with foam compound (concentrate), admixing armature, air and a foaming device. Foam, which is expanded equal or less than 1 to 20 is called heavy foam and mostly used where it is necessary to quickly cover liquid surfaces or similar surfaces. Expansion ratios from 20 to 200 produce a medium foam. The application can be as the heavy foam (at places where no draft or wind forces hinder the spreading of the foam). The water contents of this foam is considerably lower and causes less damage to the protected, but not burning materials. Foam produced at expansion ratios from 200 to 1000 is high expansion foam and mostly use to fill large volumes in an acceptable short time. The water content is very low. The disadvantage is that the visibility in filled areas is virtually zero, making additional fire fighting ineffective.

Waterless Fire Systems

Wet Chemical Systems
Wet chemical systems are designed for the protection of commercial cooking areas including exhaust hoods, ducts, plenums, and cooking surfaces. The wet chemical agent is extremely effective at quick flame knockdown, fast suppression, and re-ignition prevention.

Dry Chemical Systems
The dry chemical is well known for its use in portable extinguishers.The same chemicals, with certain special additives, are used, as well, in stationary fire systems. A variety of dry chemical agents with their own fire unique extinguishing characteristics are available to use in systems. Careful matching of the extinguishing agent to the type of fire hazard requiring protection will ensure an effective fire system.

Gaseous Extinguishing Systems
Extinguishing gases work to suppress fires by either displacing the oxygen or chemically interrupting the chain reaction within the flames (depending on the type of gas). This is naturally not valid for materials containing their own oxygen in their chemical structure or materials which react with combustion without needing oxygen to maintain the heat necessary for the reaction.

There are numerous gases and gas mixtures/blendings that can be used for fire suppression. Some are more environmentally friendly than others, while some are more effective on certain types of fires than others. Illinois Fire & Safety can help you determine which fire suppression agent is best for your particular fire concern.

Illinois Fire & Safety Company is a leading designer, installation and service company for all types of fire suppression systems. Give us a call today and let our professionals evaluate your fire protection needs. 1-888-ILLFIRE.