Disadvantages: limited to class A fires only. leaves a small amount of residue after the fire has been extinguished. water is an electrical conductor, making the extinguisher unsuitable if the class of fire has an electrical supply, or for use near live electrical equipment.
What are disadvantages of foam fire extinguisher?
Disadvantages: The liquid in the extinguisher will damage electrical equipment such as computers (although these may of course have already been damaged by the fire itself)
What is the disadvantage of water fire extinguishers?
It is dangerous to use water for fires involving flammable liquids and energized electrical equipment as the application of water spreads the fire and serves as a conductor of electricity. The use of the extinguishers must be limited to extinguishing ordinary combustibles.
What is a disadvantage of using dry powder extinguishers?
Reduces visibility when discharged, so consideration required when placing near escape routes, stairwells, etc. May aggravate respiratory conditions when discharged. Limited cooling properties. While Powder is safe for use on electrical fires, it can cause corrosion.
How does foam and water extinguish fire?
Unlike other extinguishing agents – water, dry chemical, CO2, etc., a stable aqueous foam can extinguish a flammable or combustible liquid fire by the combined mechanisms of cooling, separating the flame/ignition source from the product surface, suppressing vapors and smothering.
What is a disadvantage of dry chemical fire extinguishers that are not multipurpose?
Disadvantages: Obscures vision. More irritating than ordinary dry chemical. Nozzle pressure may cause burning liquids to splash.
What is foam extinguisher?
05 Jul 2015. 9 LITRES FOAM FIRE EXTINGUISHERS (Chemical Foam) Foam is an effective smothering agent, used for liquid fires mainly. It acts by flowing over the liquid fuel oil surface and isolating the fire from the air, also prevents re-ignition due to the foam stability.
When should you not use a foam fire extinguisher?
Foam extinguishers are also safe for use on flammable liquid fires. They CANNOT be used on electrical fires or flammable metal fires as this extinguisher could end up exacerbating the fire.
Can foam extinguisher used electrical fires?
Foam extinguishers build up of foam on the surface of the burning liquid, cutting off the oxygen supply to the fire and cooling the hot liquid. Electrical fires: If your foam extinguisher is tested to 35000 Volt (35kV) you can use the extinguishers on live electrical fires. However, keep a safety distance of 1m.
Can foam extinguishers be used on metal fires?
This type of fire extinguisher should not be used for fires caused by flammable metals, kitchen fires and fires that involve electrical equipment. These extinguishers work by creating a cooling effect on the fuel that is responsible for causing the fire.