Unlike other extinguishing agents – water, dry chemical, CO 2 , 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 .
How does a foam fire extinguisher work?
Foam agents work well on combustible materials like wood, paper, and cloth as well as flammable oils, diesel fuel, and alcohols to name a few. They are non-toxic and extinguish the fire by forming a blanket on the surface of the burning hazard , which both cools and smothers the fire by removing the oxygen.
How does a foam spray extinguisher put out fire?
HOW FOAM EXTINGUISHES A FLAMMABLE LIQUID FIRE: Fire burns because there are four elements present. ... The foam blanket separates the flames/ignition source from the fuel surface. The foam cools the fuel and any adjacent metal surfaces. The foam blanket suppresses the release of flammable vapors that can mix with air .
How do fire extinguishers put out fires?
Most fire extinguishers work by separating the fuel from the oxygen . The oxygen comes from the air. It is the same oxygen we breathe. Since the oxygen has to be in contact with the fuel, if you can coat the fuel with something that keeps the oxygen away, the fire will go out.
What should you not use a foam fire extinguisher on?
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. Foam extinguishers are ideal for premises which have multiple fire risks including offices, factories, warehouses and hotels.
What fire should a foam extinguisher not be used on?
5. Foam Fire Extinguisher. Foam fire extinguishers are suitable for class A and the flammable liquids of class B, though not effective for gaseous fires .
Can a fire extinguisher put out any fire?
Class A extinguishers can put out fires from “ordinary combustibles” such as wood, plastic or paper. Class B can put out burning liquids such as gasoline or grease. Class C can put out electrical fires. Extinguishers marked A, B and C can put out all types .
How big of a fire can an extinguisher put out?
All extinguishers are rated as to the size of fire they are designed to handle. The rating is a number from 1 to 40 for a “Class A” fire , and 1 to 640 for a “Class B” fire. For example, a 20-B rated extinguisher can handle a flammable liquid fire twice as big as a 10-B extinguisher; the rating will appear on the label.
What can put out a fire?
- If the fire is small, cover the pan with a lid and turn off the burner.
- Throw lots of baking soda or salt on it. Never use flour, which can explode or make the fire worse.
- Smother the fire with a wet towel or other large wet cloth.
- Use a fire extinguisher.
Which extinguisher is most suitable for oil fires?
Wet Chemical fire extinguishers are the most effective against Class F fires (cooking oils and fats) e.g fats, grease and oil. Therefore they are practical in a kitchen environment.
Which of these is the best to use on an electrical fire?
The best way to put out an electrical fire is with a fire extinguisher . If you don’t have one, remember these tips. 1. You should never throw water on an electrical fire because water conducts electricity and you could be electrocuted.
Why should you not use a foam or water fire extinguisher on an electrical fire?
If possible, you should try to extinguish the flames using a carbon dioxide or dry powder fire extinguisher. ... Do not try to put out an electrical fire with a water or foam extinguisher, as both of those materials can conduct electricity and potentially make the situation more dangerous .
What are the 3 methods of extinguishing a fire?
All fires can be extinguished by cooling, smothering, starving or by interrupting the combustion process to extinguish the fire. One of the most common methods of extinguishing a fire is by cooling with water.
What is the difference between ABC and co2 fire extinguisher?
ABC Powder is a multi-purpose extinguisher medium suitable for all classes of fire, however although effective, a Powder Extinguisher will leave a residue that can damage sensitive electrical equipment. If this is a concern it may be wise to use a CO2 Extinguisher.
What are the 5 types of fire?
Fire is divided into five classes ( A, B, C, D, and K ) that are primarily based on the fuel that is burning. This classification system helps to assess hazards and determine the most effective type of extinguishing agent.
What does ABC mean in fire extinguisher?
Dry Chemical Extinguishers come in a variety of types. You may see them labeled: • “DC” short for “dry chem” • “ABC” indicating that they are designed to extinguish class A,B,and C fires , or • “BC” indicating that they are designed to extinguish class B and C fires.
