Foam Suppression Systems
Every facility has different needs when it comes to fire suppression. The size of the facility, the hazard area to be protected, the authority having jurisdiction, and the assets being protected all play a big role in deciding what fire suppression system to use.
A Foam Suppression System is water based with an added extinguishing agent. It can be used where flammable or combustible liquids are used, processed, manufactured or stored, and for vapor mitigation.
How Does a Foam Suppression System Work?
There are 3 different ways a Foam system will suppress a fire:
- By removing heat at a faster rate than it’s released
- By excluding oxygen and separating the fuel from the oxidizing agent
- By vapor suppression, which dilutes the vapor phase concentration of the fuel and/or oxidizing agent below that necessary for combustion.
Types of Foam Suppression Systems:
There are 3 standard types of Foam Suppression Systems, each offering a different method of suppression based on the need of the facility.
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Low Expansion Systems
Very wet and fluid foam blanket with small foam bubbles. Commonly discharged through sprinkler systems, fire hoses, monitors, spray nozzles, and foam makers. Primary applications include flammable liquid storage (typically warehouses), process or manufacturing areas, truck or rail loading racks, fuel storage tanks, rooftop helipads, and aircraft hangars.
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Medium Expansion Systems
Dense foam blanket often two-feet deep or more. Primarily used for vapor suppression in refineries, chemical manufacturing areas and containment dike protection.
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High Expansion Systems
Large foam bubbles, more damp than wet, with a foam blanket that typically anywhere from three to forty-five feet in depth. The preferred system type when total flooding of a hazard area or large area volume protection is needed. The most common applications of high expansion systems are aircraft hangars, total flooding warehouses, and Liquified Natural Gas impound basins.
Foam Suppression Inspection, Testing, & Maintenance:
- Annual inspections
- Inspection of foam concentrate tanks to ensure that they are operable
- System flow testing
- Samples of foam concentrate for laboratory submission to ensure viability
- Correct deficiencies due to failed testing or changes to hazard being protected