February 08 2021 0Comment
Foam Systems Diagram

Special Hazard Fire Suppression Systems


Special hazard fire suppression systems can provide highly effective and reliable
protection when water-based systems are just not enough. Whether it be industrial,
military, commercial, pharmaceutical, data centers, highly flammable materials
or protection of priceless commodities, a special hazard fire protection may be
your alternative solution to protecting your assets. These systems require precision, specialized understanding and careful engineering to meet industry
standards and perform properly and effectively when needed most.

Foam systems are specifically engineered and designed for the intended use of
spaces where flammable and combustible liquids are present and where traditional
water-based systems are not adequate. At the basic level, the foam system consists
of a bladder tank, proportioner and a foam concentrate that when mixed with water
and air, produces a foam that is less dense than the liquid it serves to protect. When the foam is introduced to water soluble fuel, it forms a polymeric membrane, which creates a blanket that will separate the fuel from oxygen at the surface level and assist in smothering the fire while creating a barrier to the vapors.

Foam systems fall into three categories; Low Expansion, Medium
Expansion, and High Expansion foams:

• Low Expansion Foam
expands up to 20 times its liquid size and has a good flowability rate for long distance use. With strong adhesion properties along with its density, this makes it the least susceptible in high wind conditions compared to medium and high expansion foams and are effective for uses in outdoor locations such as helipads and ships. It is able to wet down solid surfaces while still protecting as it creates
a dense foam layer that has cooling properties as well as vapor suppression ability.

• Medium Expansion Foam
will expand from 20 to 200 times. With most of the same properties as low expansion foam, medium expansion foam can build up a larger blanket more so than low expansion foam however is less dense, making it more susceptible to high wind conditions in an outdoor application.

• High Expansion Foam
has an expansion rate that is greater than 200 times its liquid form and is generated with more air infusion and less water. These large bubbles build quickly forming a deep layer of fire fighting foam. These applications are solely used indoors in aircraft hangers, warehouses or contained rooms as they are very susceptible to windy conditions.

Important Note:
The industry is beginning to shift in regards to the use of AFFF foam in
foam systems due to their use of PFAS which include flourosurfactants.
On a state by state basis, the sale and use of AFFF is becoming restricted
in its usage and/or prohibited from purchase. It will not be long before
all of the older C8 long chain foam systems must be replaced with
fluorine free foams. It may not be as simple as a 1 for 1 exchange of
these chemicals in your existing foam systems and may require a
complete replacement of tanks, proportioners and other related equipment.