Low expansion foam
with up to 8 times expansion is produced from protein foam concentrates,
|•||with up to 20 times expansion is produced from synthetic foam concentrates,
"wet" foam with fine bubbles of relatively high weight and small volume. Low expansion foam has a good flow ability, is resistant to flames and heat, gas tight and prevents re-ignition. Depending on the foam concentrate and induction rate low expansion foam adheres well to vertical objects. Its fire extinguishing effect mainly is due to its separating and cooling properties and - if it is an AFFF - additionally to film formation.
Low expansion foam is produced in low expansion foam branch pipes, foam monitors or in stationary/mobile foam installations. Screens or downstream upgrading sections, e.g. discharge knees, which may be installed, have the effect that the water/foam concentrate mixture is expanded even better with the air drawn in and a more "stiff" foam with finer bubbles is thus produced.
is used for extinguishing fires of liquids and solid materials due to its exceptionally good flowability. The foam distributes itself over the entire surface of the fire within a very short time and provides an air-tight seal.
When fighting fires of solid materials, its good adhesiveness even on vertical surfaces and bulky incendiary matter has a particularly favourable effect. Special application methods, for example, CAFS, support this effect. Used as a preventive measure, low expansion foam suppresses the emission of flammable gases. The flammable material remains covered by a gas-tight, insulating and cooling foam layer for a long period. Thanks to its relatively high weight, a wide projection range can be attained with low expansion foam which makes a fire fighting operation possible from a safe distance.
Aqueous film forming foam concentrates such as STHAMEX-AFFF, MOUSSOL-APS, FOAMOUSSE-FFFP can be used in both expanded and non-aspirated form as an aqueous solution, for example, an airports, in petrol depots, in plastics processing and recycling industries, an ships as well as in the on- and off-shore sectors. These foam concentrates are also suitable for use in sprinkler and deluge Systems. The foam's high water releasing capacity supports the formation of an aqueous film and thus improves the flowability. The low surface tension of the foam solution increases the wetting effect when extinguishing fires of solid materials.