expansion ratio ≥ 200
CharacteristicsExtremely high foam volume and low weight. High-expansion foam contains a very high proportion of air and is, therefore, a particularly ‘dry’ foam consisting of large bubbles. It cannot be projected, due to its large volume and low weight. Extinguishing performance relies mainly on the separation, insulation and repression effects. These extinguishing effects are encouraged by a relatively high foam deterioration rate where minute water droplets are released, which, in turn, evaporate immediately due to the high combustion temperatures. The volume of water expands by a factor of 1700 when vaporised into steam, cooling the surrounding air accordingly. High-expansion foam is produced using high-expansion foam generators.ApplicationHigh-expansion foam develops its full fire extinguishing potential in enclosed spaces. Due to the extremely high expansion rate, even large areas, such as aeroplane hangars or warehouses, may be completely flooded within a short time. The water content of the foam is so low that water damage is largely avoidable. When used preventatively, high-expansion foam displaces flammable gas, providing effective protection from flames and heat exposure.