Types of fire and methods of extinguishment

There are five types of fire

Class A -  solid fire
Class B - liquid fire
Class C - gaseous fire gas
Class D - metal fire
Class E - electrical fire
Class k - kitchen fire

Class A - solid fire
Solid combustible materials ( e. g - wood, paper, plastics, clothes, etc)

Class B - liquid fire

 Liquid materials ( e.g - petrol, diesel ,                        kerosene, etc)


Class C - gas fire

 (  e.g  LPG. CNG, methene, ether, methyl , propene,)


Class D - Metal fire
 (  e. g - magnesium, sodium,potassium and sodium-potassium alloys. zirconium,uranium, titanium, and powdered aluminum)


Class  E - Electrical fire

failure or malfunction within the electrical components of equipment or machinery can cause electrical fires. Electrical fires originate in electric wires, cables, circuit breakers, and within electrical components.


Class F -kitch fire

Kitchen vegetables oil, and other materials burn it is covered in class K  kitchen fire.



Method for extinguishment of fire

1. Cooling             ( Reduce temperature of fuel)
2. smothering.     ( cut contact of O2 from fuel)
3. Starvation.       (isolate the fuel)
4. Chain braking Requirements for combustion 

.*For combustion of any substance any three part of tetrahedron is required 

*If one is eliminate from combustion the fire can be controlled

* chain braking system is used when O2 (oxygen) dose not required for continue combustion.


Extinguisher ( first aid fire control alliance) 

1. Water Extinguishers

Overview:
Water extinguishers are the most common fire extinguisher type for class A fire risk. Most premises will require either water or foam extinguishers.

Label Colour:
- Bright Red

Use for:
- Organic materials such as:
o Paper and cardboard
o Fabrics and textiles
o Wood and coal

Do not use for:
- Fires involving electrical equipment
- Kitchen fires
- Flammable gas and liquids

How water extinguishers work:
The water has a cooling effect on the fuel, causing it to burn much more slowly until the flames are eventually extinguished.

2. Foam Extinguishers

Overview:
Foam extinguishers are most common type of fire extinguisher for Class B fires, but also work on Class A fires as they are water-based.

Label Colour:
- Cream

Use for:
- Organic materials such as:
o Paper and cardboard
o Fabrics and textiles
o Wood and coal
Plus:
- Flammable liquids, like paint and petrol

Do not use for:
- Kitchen fires
- Fires involving electrical equipment
- Flammable metals

How foam extinguishers work:
As with water extinguishers, foam extinguishers have a cooling effect on the fuel. On burning liquids, the foaming agent creates a barrier between the flame and the fuel, extinguishing the fire.

3. Dry Powder Extinguishers

Overview:
Standard dry powder extinguishers are also called 'ABC' extinguishers because they tackle class A, B and C fires, however they are not recommended for use in enclosed spaces. This is because the powder can be easily inhaled, and also the residue is very difficult to clean up after. ABC powder extinguishers can also be used on some electrical fires. Specialist dry powder extinguishers are used for flammable metals.

Label Colour:
- Blue

Use for:
- Organic materials such as:
o Paper and cardboard
o Fabrics and textiles
o Wood and coal
Plus:
- Flammable liquids, like paint and petrol
Plus:
- Flammable gases, like liquid petroleum gas (LPG) and acetylene
Plus:
- Fires involving electrical equipment up to 1000v

Specialist dry powder extinguishers are only used on flammable metals, such as titanium and magnesium.

Do not use for:
- Fires involving cooking oil
- Fires involving electrical equipment over 1000v
- or in enclosed spaces, such as offices or residential properties

How dry powder extinguishers work:
Dry powder extinguishers smother fires by forming a barrier between the fuel and the source of oxygen.

4. Carbon Dioxide (CO2) Extinguishers

Overview:
CO2 extinguishers are predominantly used for electrical fire risks and are usually the main fire extinguisher type provided in computer server rooms. They also put out Class B fires (flammable liquids, such as paint and petroleum).

Label Colour:
- Black

Use for:
- Flammable liquids, like paint and petrol
- Electrical fires

Do not use for:
- Kitchen fires – especially chip-pan fires
- Combustible materials like paper, wood or textiles
- Flammable metals

How CO2 extinguishers work:
CO2 extinguishers suffocate fires by displacing the oxygen the fire needs to burn.

5. Wet Chemical Extinguishers

Overview:
Wet chemical extinguishers are designed for use on Class F fires, involving cooking oils and fats.  They can also be used on Class A fires although it is more usual to have a foam or water extinguisher for this type of fire risk.

Label Colour:
- Yellow

Use for:
- Cooking oil/fat fires
- Organic materials such as:
o Paper and cardboard
o Fabrics and textiles
o Wood and coal

Do not use for:
- Flammable liquid or gas fires
- Electrical fires
- Flammable metals

How wet chemical extinguishers work:
Wet chemical extinguishers create a layer of foam on the surface of the burning oil or fat, preventing oxygen from fuelling the fire any further. The spray also has a cooling effect.

Construction of extinguisher 

1. stored pressure type extinguisher 

  

Except DCP ( dry chemical powder) every extinguisher made in those type. 

Because DCP need expelling agent ( gas)  that's why DCP made in gas cartridge type only. 

Opration 

Short formula for Opration of extinguisher 

P A S S

 ( Pull, Aim, Squeeze, Sweep). 

 Stored pressure fire extinguishers contain the extinguisher agent (water, powder, foam, CO2, etc.) and the pressurising gas (dry air or oxygen-free nitrogen) in the same cylinder.Stored pressure fire extinguishers contain the extinguisher agent (water, powder, foam, CO2, etc.) and the pressurising gas (dry air or oxygen-free nitrogen) in the same cylinder.

1. Before moving the extinguisher, check that the safety pin/clip and tamper seal are in place (Fig. 1) and that the extinguisher has not been operated (if this is not the case, then make the fire extinguisher safe before going any further by fitting a safety pin and tamper seal)
2. Check the extinguisher service label, if the extended service is not due then proceed.
3. Visually inspect the fire extinguisher body for external corrosion or damage that could impair the safe operation of the extinguisher, in particular check the head cap. If this is made from plastic, check for UV degradation.
4. Ensure that the manufacturer's extinguisher labelling is in good condition, legible and printed in English.
5. Weigh the extinguisher ensuring that it meets the weight recorded on the service label (Investigation and recharge is required if a weight loss exceeds 10%).
6. Verify the pressure gauge indicator is in the green zone of the gauge (Fig. 2). Verify that the gauge is in working order by carrying out a gauge test with a pump gauge tester or pin test. (This step is not applicable for CO2 fire extinguishers)
7. Remove the discharge hose from the extinguisher head cap, check the hose and nozzle for damage and ensure that the hose is clear from obstruction (Fig. 3). Remove the hose 'O' ring and replace if applicable.
8. Break the tamper seal by withdrawing the safety pin/clip. In the case of a metal pin; check that it is in good condition. Refit/replace the safety pin/clip and then secure in place with a tamper seal.
9. Replace any 'O' rings where components have been disassembled.
10. Wipe down the extinguisher exterior with a cloth.
11. Fill in the details required on the service label (date, weight, engineer initials and next service date).
12. If applicable, ensure that the wall mountings are secure before mounting the extinguisher back in position
13. If there is a sign above the extinguisher check that it is appropriate and is in good condition

Stored pressure fire extinguishers contain the extinguisher agent (water, powder, foam, CO2, etc.) and the pressurising gas (dry air or oxygen-free nitrogen) in the same cylinder.

1. Before moving the extinguisher, check that the safety pin/clip and tamper seal are in place (Fig. 1) and that the extinguisher has not been operated (if this is not the case, then make the fire extinguisher safe before going any further by fitting a safety pin and tamper seal)
2. Check the extinguisher service label, if the extended service is not due then proceed.
3. Visually inspect the fire extinguisher body for external corrosion or damage that could impair the safe operation of the extinguisher, in particular check the head cap. If this is made from plastic, check for UV degradation.
4. Ensure that the manufacturer's extinguisher labelling is in good condition, legible and printed in English.
5. Weigh the extinguisher ensuring that it meets the weight recorded on the service label (Investigation and recharge is required if a weight loss exceeds 10%).
6. Verify the pressure gauge indicator is in the green zone of the gauge (Fig. 2). Verify that the gauge is in working order by carrying out a gauge test with a pump gauge tester or pin test. (This step is not applicable for CO2 fire extinguishers)
7. Remove the discharge hose from the extinguisher head cap, check the hose and nozzle for damage and ensure that the hose is clear from obstruction (Fig. 3). Remove the hose 'O' ring and replace if applicable.
8. Break the tamper seal by withdrawing the safety pin/clip. In the case of a metal pin; check that it is in good condition. Refit/replace the safety pin/clip and then secure in place with a tamper seal.
9. Replace any 'O' rings where components have been disassembled.
10. Wipe down the extinguisher exterior with a cloth.
11. Fill in the details required on the service label (date, weight, engineer initials and next service date).
12. If applicable, ensure that the wall mountings are secure before mounting the extinguisher back in position
13. If there is a sign above the extinguisher check that it is appropriate and is in good condition

2.Gas cartridge type extinguisher

Note - many time it is one time usable 

1. Insure that pressure gauge pin direction in green zone. 

2. See expiry date, if extinguisher expire then don't use it.

3. Conform that it is suitable for fire according class of fire. 

4. Remove from wall and put it down, maintaining     distance 6 meter from fire. 

5. Remove safety pin.                                                             

6. Hold outlet pip in left hand.                                             

7. Press the handle and aim on fire.                                  

8. Sweep on fire.