Foam Enhanced Systems

Foam systems are generally used in applications where flammable liquids are present. Typical applications include fuel storage tanks and bund areas, petrochemical plants, aircraft hangars and facilities that store flammable or volatile liquids. The foam not only contains extinguishing agents to put out the fire but also acts as a “blanket” to exclude oxygen “feeding” the fire and to provide vapour suppression so protecting against re-ignition.

The foam system involves mixing water with a foam concentrate to a pre-determined proportion. The proportion of foam concentrate used is either 1%, 3% or 6% dependant on the application. Again, dependant upon the risk being protected, the foam solution can be applied in 3 states; low, medium and high expansion.

Low expansion – used at an expansion ratio of up to 20:1 is used where the foam needs to be directed at the fire. This is often used in conjunction with manned or remote control monitors

Medium Expansion - used at an expansion rate of between 20:1 and 200:1 and is where there is a need to extinguish large surface area fires. Typical examples are in fuel storage tank farms or fuel spill fires in bund areas.

High Expansion – used at an expansion rate of between 200:1 and 1000:1 to extinguish large volume areas. Typical examples are for use in aircraft hangars or inaccessible areas such as tunnels and mines.
 

There are various types of foam available from a basic protein foam through to Aqueous Film Forming Foam (AFFF) and Film Forming Flouroprotein (FFFP) with alcohol resistant foam being used for polar solvents.

All foam systems are designed in accordance with international standards namely:-

• BS5306 part 6.1 (low expansion foams)
• FM / UL
• NFPA11 (Low, Medium and High Expansion Foams)
• NFPA16 (Foam Enhanced Sprinkler Systems)

The standard applied is dependant on application and risk.

For any further information regarding this product please either visit our technical library or contact us.