How Fire Extinguisher Work

Fire extinguishers parts consist of tube, pressure gauge, nozle, safety pin, handle and high pressure gas canister at the top inside the tube. The tube filled with water or a smothering material, such as CO2.
When you pull the safety pin and squeeze the handle, the handle pushes on an actuating rod which presses the valve down to open a passage to the nozzle. The compressed gas inside a canister is released, applying a downward pressure on the fire-extinguishing material (water or smothering material). This pushes the material out the nozzle with high amounts of pressure.

Water Extinguishers
Water extinguishers are filled with regular tap water and pressurized with oxygen. The best way to remove heat is to dump water on the fire but, depending on the type of fire, this is not always the best option.

Dry Chemical Extinguishers
Dry chemical extinguishers are filled with either foam or powder, usually sodium bicarbonate (baking soda) or potassium bicarbonate, and pressurized with nitrogen. Baking soda is effective because it decomposes at 158 degrees Fahrenheit and releases carbon dioxide (which smothers oxygen) once it decomposes. Dry chemical extinguishers interrupt the chemical reaction of the fire by coating the fuel with a thin layer of powder or foam, separating the fuel from the surrounding oxygen.
Warning: when used indoors, powder can obscure vision or damage goods and machinery. It is also very messy.

Carbon Dioxide (CO2) extinguishers
CO2 extinguishers contain carbon dioxide, a non-flammable gas, and are highly pressurized. The pressure is so great that it is not uncommon for bits of dry ice to shoot out. CO2 is heavier than oxygen so these extinguishers work by displacing or taking away oxygen from the surrounding area. CO2 is also very cold so it also works by cooling the fuel.
Carbon Dioxide is ideal for fires involving electrical apparatus, and will also extinguish class B liquid fires, but has NO POST FIRE SECURITY and the fire could re-ignite.

How to use fire extinguisher

Before using your fire extinguisher, be sure to read the instructions before it's too late. Although there are many different types of fire extinguishers, all of them operate in a similar manner.

Even though extinguishers come in a number of shapes and sizes, they all operate in a similar manner. Here's an easy acronym for fire extinguisher use:



Pull the pin at the top of the extinguisher that keeps the handle from being accidentally pressed.

Aim the nozzle toward the base of the fire, not the flame

Squeeze the lever slowly. Stand approximately 8 feet away from the fire and squeeze the handle to discharge the extinguisher. If you release the handle, the discharge will stop.When you pull the safety pin and squeeze the lever, the lever pushes on an actuating rod which presses the valve down to open a passage to the nozzle. The compressed gas is released, applying a downward pressure on the fire-extinguishing material. This pushes the material out the nozzle with high amounts of pressure.

Sweep the nozzle back and forth at the base of the fire. After the fire appears to be out, watch it carefully since it may re-ignite!


A typical fire extinguisher contains 10 seconds of extinguishing power. This could be less if it has already been partially discharged.

Once the fire is out, don't walk away! Watch the area for a few minutes in case it re-ignites. Recharge the extinguisher immediately after use.

When we use Fire Extinguisher ?

Fire needs fuel, oxygen and heat in order to burn. In simple terms, fire extinguishers remove one of these elements by applying an agent that either cools the burning fuel, or removes or displaces the surrounding oxygen.

Fire extinguishers are filled with water or a smothering material, such as CO2. By pulling out the safety pin and depressing the lever at the top of the cylinder (the body of the extinguisher), this material is released by high amounts of pressure.

Portable fire extinguishers are valuable for immediate use on small fires. They contain a limited amount of extinguishing material and need to be properly used so that this material is not wasted. For example, when a pan initially catches fire, it may be safe to turn off the burner, place a lid on the pan, and use an extinguisher. By the time the fire has spread, however, these actions will not be adequate. Only trained firefighters can safely extinguish such fires.

Use a fire extinguisher only if:

- You have alerted other occupants and someone has called the fire department;
- The fire is small and contained to a single object, such as a wastebasket;
- You are safe from the toxic smoke produced by the fire;
- You have a means of escape identified and the fire is not between you and the escape route; and
- Your instincts tell you that it is safe to use an extinguisher.
If all of these conditions are not present, you should NOT try to use a fire extinguisher. Alert other occupants, leave the building following your home escape plan, go to the agreed upon meeting place, and call the fire department from a cell phone or a neighbor's home.

Types of Fire Extinguisher

There are 4 main types of fire extinguishers used for fighting fire:
- Water
- Foam
- Carbon dioxide
- Powder.

Fire extinguishers used to be different colours but now, in a workplace, they must all be red. To tell them apart they all have a different coloured 'flash' on them.

Type of Extinguisher Colour of Flash
Water type : Red
Foam type : Cream
Carbon Dioxide type : Black
Powder type : Blue

Different types of fires require different types of extinguishers. For example, a grease fire and an electrical fire require the use of different extinguishing agents to be effective and safely put the fire out.
With so many fire extinguishers to choose from, selecting the proper one for your home can be a daunting task. Everyone should have at least one fire extinguisher at home, but it's just as important to ensure you have the proper type of fire extinguisher. Fire protection experts recommend one for the kitchen, the garage and workshop.

Fire extinguishers are divided into four categories, based on different types of fires. Each fire extinguisher also has a numerical rating that serves as a guide for the amount of fire the extinguisher can handle. The higher the number, the more fire-fighting power. The following is a quick guide to help choose the right type of extinguisher.

Class A extinguishers are for ordinary combustible materials such as paper, wood, cardboard, and most plastics. The numerical rating on these types of extinguishers indicates the amount of water it holds and the amount of fire it can extinguish.

Class B fires involve flammable or combustible liquids such as gasoline, kerosene, grease and oil. The numerical rating for class B extinguishers indicates the approximate number of square feet of fire it can extinguish.

Class C fires involve electrical equipment, such as appliances, wiring, circuit breakers and outlets. Never use water to extinguish class C fires - the risk of electrical shock is far too great! Class C extinguishers do not have a numerical rating. The C classification means the extinguishing agent is non-conductive.

Class D fire extinguishers are commonly found in a chemical laboratory. They are for fires that involve combustible metals, such as magnesium, titanium, potassium and sodium. These types of extinguishers also have no numerical rating, nor are they given a multi-purpose rating - they are designed for class D fires only.

Fire Extinguisher

Fire is a basic necessity for survival, yet it is also the deadliest and unpredictable foe. Since the early 1800's man has looked for ways to protect home and hearth from fire related disasters and injury. It was at this time that the first fire extinguisher was patented, it was more of an explosive device that needed to be triggered by fuse to scatter the flame retarding liquid. The modern and portable ones we use was patented in 1818 to British Captain George William Manby. A fire has three elements: heat, oxygen and fuel. The heat starts it all bringing any material to the point of igniting, A fuel source supports the burning, while the oxygen sustains the fire for spreading and doing greats damage.

Since that time fire extinguishers are active safety devices that are required in the home, work place, restaurants mostly all places susceptible to fire. These are a person's first line of defense in containing fire. There are 4 types (classes) of fire extinguishers which are used for a particular type of fires. These are indicated on the cylinder as picture/labeling in the new generation extinguishers or as geometrical and letter designation in older cylinder versions.

Choosing a fire extinguishers according to its usage is best determined by the classifications.
Fire class 'A' is used for ordinary combustibles,
Fire class 'B' is used for flammable liquids and gas,
Fire class 'c' is for live electrical equipments,
Fire class 'd' is solely for combustible metals,
Fire class 'K' is for burning oils (ie. cooking oil).

Classification and fire extinguisher components are tested by Underwriter's Laboratories. This is the same body that does routine checks and evaluates a fire extinguisher according to it capability and potential ability to extinguish types of fire. Continuous checks and tests are done in UL laboratories to ensure the public' s safety and the authenticity of the extinguishers being used.

In determining such, the usage of a particular type of extinguisher is guaranteed to work. This also prevents the misuse and erroneous use of an extinguisher type which would only feed the fire.

Types Of Fire

Assigning a type or class to a fire extinguisher is based on the source of the fire. Since not all fires start from the same fuel source, Different materials or fuels create different fires and require different types of fire extingushing agents.
stopping it from spreading needs the right extinguisher for the fire. Matching both the extinguisher with the fire, one must honestly assess the fire hazards posed in the area you occupy. Having a fire extinguisher not matched with the fire type that may possibly happen in your environment is a waste of money and energy- that is if you get to try and arrest the blaze with the wrong apparatus.

There are four different types, or classes of fire.

Class A fires involve solid materials of an organic nature such as wood, paper, cloth, rubber and plastics that do not melt.

Class B fires involves liquids. They include petrol, diesel, thinners, oils, paints, wax, cooking fat and plastics that melt.

Class C fires involve electricity.

Class D fires involve flammable metals such as magnesium, aluminium, titanium, sodium and potassium.

Some fires may involve a combination of these classifications.

The classification of fire is a guide on what kind of fire extinguisher is used in varying situations.
Some types of fire extinguishing agent can be use on more than one class of fire.
Others have warnings where it would be dangerous for the operator to use a particular fire extinguishing agent.
Some fires may involve a combination of these classifications. Your fire extinguishers should have ABC ratings on them.

Fire

Every day we always use fire in our life. But most people don't understand fire. Only when we know the true nature of fire can we prepare ourselves and our families. Each year many peoples die and injured in fires, many of which could be prevented if we know the basic facts about fire. Below are some simple facts that explain the particular characteristics of fire :

1. Fire is FAST!
There is little time!
In less than 30 seconds a small flame can get completely out of control and turn into a major fire. It only takes minutes for thick black smoke to fill a house. In minutes, a house can be engulfed in flames. Most fires occur in the home when people are asleep. If you wake up to a fire, you won't have time to grab valuables because fire spreads too quickly and the smoke is too thick. There is only time to escape.

2.Fire is HOT!
Heat is more threatening than flames.
A fire's heat alone can kill. Room temperatures in a fire can be 100 degrees at floor level and rise to 600 degrees at eye level. Inhaling this super hot air will scorch your lungs. This heat can melt clothes to your skin. In five minutes a room can get so hot that everything in it ignites at once: this is called flashover.

3.Fire is DARK!
Fire isn't bright, it's pitch black.
Fire starts bright, but quickly produces black smoke and complete darkness. If you wake up to a fire you may be blinded, disoriented and unable to find your way around the home you've lived in for years.

4.Fire is DEADLY!
Smoke and toxic gases kill more people than flames do.
Fire uses up the oxygen you need and produces smoke and poisonous gases that kill. Breathing even small amounts of smoke and toxic gases can make you drowsy, disoriented and short of breath. The odorless, colorless fumes can lull you into a deep sleep before the flames reach your door. You may not wake up in time to escape.

Fire Safety Tips
In the event of a fire, remember time is the biggest enemy and every second counts!
Soon extinguishe fire with fire extinguisher before be bigger. but if you can not extinguishe you must escape first, then call for help. Develop a home fire escape plan and designate a meeting place outside. Make sure everyone in the family knows two ways to escape from every room. Practice feeling your way out with your eyes closed. Never stand up in a fire, always crawl low under the smoke and try to keep your mouth covered. Never return to a burning building for any reason; it may cost you your life.
Finally, having a working smoke alarm dramatically increases your chances of surviving a fire. And remember to practice a home escape plan frequently with your family.