Fire - Types - Extinguishers

Module-1,Part-3:

TABLE OF CONTENT:

Fire & their Types.
Factors Depends on Fire.
Extinguishing a Fire.
Fire Extinguisher & their Types.
Procedutre in the event of Fire.
Operation of the Extinguisher.

Fire:

Fire is the burning of combustible material, like burning of wood, paper, oil gas etc.

Factors depend on fire:

· Fuel: Any substance, liquid, solid or gas will burn, if there is oxygen and high enough temperatures.

· Heat: Every fuel will begin to burn at a certain temperature. It varies and depends on the fuel. Solids and liquids give off vapor when heated, and it is this vapor which ignites. Some liquids do not have to be heated as they give off vapor at normal room temperature say 15⁰C, eg. petrol.

· Oxygen: Usually exists in sufficient quantity in air to keep a fire burning.

Types of fire:

Type of fire	Combustible material	Fire Extinguisher used
Class-A	Wood, Cloth, Paper etc.	cooling with water
Class-B	Flammable liquids (Petrol, Diesel, Kerosene etc.)	CO₂, Dry powder
Class-C	Flammable gas (Methane or LPG)	Dry powder
Class-D	Electrical fire or Metal fire (burning of sodium)	Halon, Carbon dioxide, dry powder and vaporizing liquid (CTC) extinguishers

Extinguishing of fire:

Isolating or removing any of these factors from the combination will extinguish the fire. There are three basic ways of achieving this.

·         Starving the fire of fuel removes this element.
·         Smothering - ie. isolate the fire from the supply of oxygen by blanketing it with foam, sand etc.
·         Cooling - use water to lower the temperature.

Fire Extinguisher:

A portable device that discharges a jet of water, foam, gas or dry powder to extinguish fire.

Types of fire Extinguisher:

i. Water-filled extinguishers

Ø This type of fire extinguisher is used for Class-A fire.

Ø When the water is sprayed the water converts into steam (Due to heat) & consumes the heat and cools the place.

Ø There are two types • Gas cartridge type • Stored pressure type.

Ø This must not be used in case of Class-D fire.

Ø All water extinguisher have a RED label.

ii. Foam extinguishers

Ø This type of fire extinguisher is used for Class-A fire.

Ø Foam covers the fire or fuel like blanket and prevents air or vapor to get in & out.

Ø This must not be used in case of Class-D fire.

Ø All foam extinguisher have a CREAM label.

iii. Dry powder extinguishers

Ø This type of fire extinguisher is used for Class-A, Class-B, Class-C, Class-D fire.

Ø Dry powder creates a barrier between Oxygen & fuel.

Ø This must not be used in closed space or room.

Ø All dry powder extinguisher have a BLUE label.

iv. Carbon dioxide (CO₂) extinguishers

Ø This type of fire extinguisher is used for Class-A, Class-B, Class-C, Class-D fire.

Ø CO₂ replaces the oxygen from the place of fire and starves the fire from oxygen.

Ø This must not be used in closed space or room.

Ø All CO₂ extinguisher have a BLACK label.

v. Halon extinguishers

Ø This type of fire extinguisher is used for Class-A, Class-B, Class-C, Class-D fire.

Ø Halon extinguishers filled with carbon-tetrachloride and Bromochlorodifluoro methane (BCF). They may be either gas cartridge or stored pressure type.

Ø Halon extinguishers work by Cutting off the supply of oxygen.

Ø This must not be used in closed space or room.

Procedure in the event of a fire:

Raise an alarm.
Turn off all machinery and power (gas and electricity).
Close the doors and windows, but do not lock or bolt them. This will limit the oxygen fed to the fire and prevent its spreading.
Try to deal with the fire if you can do so safely. Do not risk getting trapped.
Anybody not involved in fighting the fire should leave calmly using the emergency exits and go to the designated assembly point.

Operation of the extinguisher :( Remember P.A.S.S.)

Ø P for Pull (Pull the safety pin from the handle (Pin located at the top of the fire extinguisher))

Ø A for Aim (Aim the extinguisher nozzle or hose at the base of the fire (this will remove the source of fuel fire))

Ø S for Squeeze (Squeeze the handle lever slowly to discharge the agent)

Ø S for Sweep (Sweep side to side approximately 15 cm over the fuel fire until the fire is put off)

ALSO READ:

Module-1, Part-1: Introductionto ITI Electrician Trade

Module-1, Part-2: Organizationof ITI’s-safety Rules-Safety Sign-Hazards

Module-1, Part-3: Fire-Types-Extinguisher

Module-1, Part-4: RescueOperation-First aid Treatment-Artificial Respiration

Module-1, Part-5: Guidelines for cleanness & maintenance-Standardization-5’S

Module-1, Part-6: Disposalof waste Material- PPE