Fire Extinguishers

Fire Extinguishers

A fire extinguisher is a portable, active fire protection device used to put out or control small fires, especially in emergencies. It is not suitable for fires that are out of control or have spread significantly. Fire extinguishers come in different types, each designed for particular classes of fire.

Types of Fire Extinguishers:

• Water: Water extinguishers are designed for use on Class A fires, which involve ordinary combustibles like paper, cardboard, fabrics, textiles, wood, and coal. They work by cooling the fuel to slow down the burning process. Water extinguishers should not be used on electrical or kitchen fires, or flammable gases and liquids.
• CO2: Carbon dioxide (CO2) extinguishers are mainly used for electrical fires and Class B fires, which involve flammable liquids like paint and petroleum. They work by suffocating the fire, displacing the oxygen it needs to burn. CO2 extinguishers are not suitable for kitchen fires, combustible materials like paper, wood, or textiles, or flammable metals.
• Dry Chemical Powder: Dry chemical powder extinguishers can be used on Class A, B, and C fires. They extinguish the fire by interrupting the chemical reaction that fuels it.
• Foam: Foam extinguishers are used for fires involving flammable liquids such as petrol, diesel, paints, solvents, and fats like grease and oils. Foam can extinguish the fire and quickly forms over water-insoluble hydrocarbon fuel surfaces.
• Wet Chemical: Wet chemical extinguishers are designed for fires involving cooking oils and greases, such as animal and vegetable fats.

Fire extinguishers are typically composed of a cylindrical pressure vessel that holds a fire extinguishing agent. These cylinders are designed to withstand the pressure of the stored agent and undergo strict safety standard testing. A pressure gauge indicates the pressure level. Fire extinguishers often have a safety pin to prevent accidental discharge, a nozzle or hose to direct the extinguishing agent, and labels with instructions. There are two main types of fire extinguishers: stored-pressure and cartridge-operated. Stored-pressure extinguishers store the expellant in the same chamber as the firefighting agent and are the most common type. Cartridge-operated extinguishers have the expellant gas in a separate cartridge that is punctured before use.