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Fire extinguishing type and details

Fire extinguishing type and details:

Portable fire extinguishers are also known as chemical fire extinguishers or First Aid Fire Fighting Appliances.

These extinguishers are highly useful to prevent small fire from hecoming a big one, provided these are used when the fire is just in starting stage, say within first five minutes. These are light weight, S all in size which can be easily carried by hand.

Larger models of certain types are also available which are known as “engines”. These remounted control eyes which can be moved manually or toed to motor vehicles.

  • Water Types Extinguishers:
  • Soda Acid Extinguisher:

Sodium Bicarbonate + Sulphuric Acid ~ Sodium Sulphate + Water


The outer container is cylindrical in shape and is made of mild steel sheet of 1. 25 mm thickness. It is provided with a nozzle at the top curve. There is a perforated cage provided in such a way that it hangs at the top from a support. Inside this cage is placed a glass phial which contains77.3 ml. of sulphuric acid of 1.8333 specific gravity.

The cap of the extinguisher which is made of brass or aluminium fitted with a spring loaded plunger having a striker at the bottom.

The outer containers filled with 9 litres of solution of sodium bi carbonate (8%) in water such that the level does not exceed the marked level indicator. the outer container is also provided with two handles, one at the top and the other at the bottom. Also two hooks are provided to mount the extinguisher on a wall or to a stand. The spring loaded plungers provided with a safe type to prevent its UN-intentional pressing, and activation.


A class fires involving ordinary solid carbon substances such as wood, paper, Textiles etc.


Portable– 9 Litre.

Mobile – 50 Litre, 150 Litre.


The operations carried out in the sequence of following steps:

Step – I:

Pull out the safety clip.

Step – II:

Takeout the extinguisher from the mounting by holding the top handle with right hand and the bottom handle with the left hand.

Step – III:

Shake the extinguisher by moving left to right, right to left 3 to 4 times in horizontal position.

Step – IV:

Invert the extinguisher and hit the knob against a hard surface.

Step – V:

Holding the extinguisher in the same position direct the jet of water to the base of fire till all contents are exhausted.

Step – VI:

Keep the used extinguisher in horizontal position and mark it as “M’I”.


At the strike of the plunger the acid phíal breaks, releasing the acid to react with solution of sodium bicarbonate.

Sodium bicarbonate+ Sulphuric Acid -7 Sodium Sulphate + Water + CO2.

The CO2 gas so produced acts as an expelled of water by pressurizing the extinguisher to 6- 7 kg/cm2. It does not play any role in extinguish of fire. The jet of water shall reach up to 6 meters for the first one minute. The 95% contents of the extinguisher shall exhausting 2 minutes.


Steps to Recharge an extinguisher are as follows:-

  • Unscrew the cap.
  • Withdraw the cage
  • Thoroughly clean the container.
  • Take about 9 litres of clean warm water in a bucket and add sodium bicarbonate after opening the recharge sachet. Stir well and make sure that entire quantity of the recharges dissolved.
  • Pour this solution into the outer container through cloth strainer up to the markup level indicator.
  • Insert the acid phial into the cage and place it inside the container.
  • See that the plunger moves smoothly. Grease it lightly.
  • Slightly grease the threads of the container and tighten the cap firmly.


Physical Inspection: Open the extinguisher every three months to check holes, nozzle washer etc. Are in good condition.

Each extinguisher shall be tested by discharge once every year from the date of charging. The extinguisher shall be tested hydraulically once every 4 years at 25pressure for 5 minutes.



Every extinguisher must be clearly labelled in a permanent manner to indicate the name of the manufacturer:

  • Capacity
  • Year of manufacture
  • Method of Operation
  • The class of Fire.

Water Type Extinguishers :

These extinguishers are identical in appearance and construction to SODA ACID type of extinguishers. The only exception is that instead of acid phial these extinguishers are provided with C02 cartridge which is screwed to the cap of the extinguisher, The C02 cartridge has a sealing disc. The plunger has a piercing type nail attached to it in such a way that it will puncture the sealing disc of CO2 cartridge when pushed down.

There are two types of this extinguishers based on their posit on for operation.

Upright type:

These are provided with a dip pipe (siphon tube) attached to the outlet point with or without a discharge hose pipe.

Invertible type:

There is no dip pipe in this type of extinguishers ‘and no discharge pipe is provided.


Class a fires involving ordinary solid carbonaceous fuels.


Portable– 9 Litres

Mobile – 50 Litres, 150 Litres.


Upright type:

  • Remove the safety clip
  • Remove from the wall/stand mountings by holding the top handle with the left ‘ hand.
  • Place it on ground at 6 meter or less from the scene, of fire.
  • Hold the pipe in left hand and press the knob hard enough to puncture the C02 cartridge seal disc.
  • Direct the jet at the base of the fire by lifting the extinguisher with right hand. Move around the fire to extinguish the last clinker.
  • Use the entire contents of the extinguisher. Place the empty extinguisher in the horizontal position after use.

Invertible type:

See Soda Acid Type Extinguisher Operation.


At pressing the knob, C02 gas cartridge gets puncture. C02 gas pressurizes the extinguisher up to 6 to 7 kg/cm2 pressure. The watering the out er-vessel is thrown out through the squeeze nozzle. The throw is about 20 feet for the first minute and 95% of the total water comes out in 2 minutes.


Steps to recharge a water type extinguisher are as follows:-

  • Open the cap.
  • Clean the extinguisher and its parts thoroughly.
  • Pour clean watering the container up to maximum filling mark.
  • Replace CO2 cartridge with a new one.


  • Check one in three months /Inside & Outside of container for any corrosion or erosion.
  • Check the weight of CO2 cartridge. Replace if the loss is more than 10%.
  • The weight is marked on neck of every cartridge.
  • Check all movable parts for their free movement.
  • Check discharge performance once every year.
  • Test the container hydraulically at 25 kg /cm2 pressure and the tube if fitted, once 4 years.


Every extinguisher must be dearly labelled in a permanent manner to indicate.

  • The name of the manufacturer
  • Capacity.
  • Year of manufacture.
  • Method of Operation.
  • The class of Fire.

Stored Pressure type of water extinguishers :

The extinguisher is cylindrical in shape. It is made with 1. 25 mm thick MS Plate ether welded or mounded. A siphon tube passed through the cap which is provided with a squeeze grip type valve. This valve is provided with a safety pin. The discharge of the valve is provided with a rubber or PVC discharge tube. The discharge tube is provided with a nozzle. It is pre- pressurized with air.


Portable– 9 Litre.

Mobile – 50 Litre, 150 Litre.


  • It is meant to fight au” class fires.
  • Take the extinguisher to site of fire and place it about 6 meters away.
  • Remove safety pip.
  • Hold nozzle and press the squeeze grip with the other hand.
  • Direct the jet of water at base fire.


  • Since the extinguisher is pre-pressurized up to 7, 0 kg/em 2 water will came out as soon as the valve is pressed, the range is around 10 feet.


  • Send the extinguisher to the supplier for recharging.


  • Check one in three months/ Inside & Outside of container for any corrosion or erosion
  • Check the weight of CO, cartridge. Replace if the loss is more than 10%. The weight marked on neck of every cartridge.
  • Check all movable parts for their free movement.
  • Check discharge performance once every year.
  • Test the container hydraulically at 25 kg /cm2 pressure and the tube if fitted. Once 4 years.


Every extinguisher must be clearly label to indicate

  • The name of the manufacturer.
  • Capacity.
  • Method of Operation.
  • Year of manufacture.
  • The class of Fire.

Foam Extinguishers:

This extinguisher has a cylindrical outer container made of best sheet of steel of 1.25 mm thickness with lead coating inside. This tested at 25 kg/cm2 hydraulic pressure for 5 minutes. A partly channelled spindle passes through the centre of brass cap. The one end of the spindle carried sealing disc which closes the inner container; the other end connected to a “T” handle. When this handles pulled up it opens the seal of the inner container.

The inner containers made of sheet of copper and its capacity is 1 litre. This containers inside the outer container duly supported at the neck of the extinguisher. There are holes on the top of the inner vessel so that once the “T” handle can be lifted up and extinguisher turned upside down the contents will readily mix with the contents of the outer vessel. A nozzle is provided at the cap of the extinguisher. The handle is also provided at the cap.

The outer vessel contains 7. 8 litres of 8% solution of Sodium bicarbonate while the inner vessel contains 1 litre of 13% aluminium sulphate solution.


‘B’ Class fires involving liguid fuels such as Kerosene Oil, Benzene and Petrol etc.


Portable – 9 Litre

Mobile – 50 Litre, 150 Litre


Step – I

Remove the extinguisher from the wall/stand mounting and take it to scene of fire up to 6 meter away.

Step – II

Shake the extinguisher3 – 4 times

Step – III

Place it on the ground. Lift the T’ handle and give half turn to the left the lock pin on the shaft of handle, will sit in the grove provided for the purpose.

Step – IV

Hold the top handle with right hand and the bottom one with the left.

Step – V

Turn the extinguisher upside down,

Step -VI

Allow the jet of foam to fangentlyon the surface of the burning fuel.

Step -VII

Keep the empty extinguisher in horizontal position and write “MT” with a marker pen. Performance: At turning the extinguisher upside down aluminium update solution of the inner vessel mixes with sodium bicarbonate solution of the outer vessel, the chemical reaction takes place with the formation of multiple compounds which give foam inaction. C02 gas also generated during the reaction which pressurizes the extinguisher to 6 to7 kg/cm2 pressure. The contents of the extinguisher are pushes all it through a nozzle where atmospheric air enters and converting the contents into a rich foam.


  • Unscrew the cap.
  • Remove the inner vessel.
  • Clean the extinguisher thoroughly with water both from inside and the outside.
  • Clean the outlet nozzle. Take 7. 8 litres of watering a bucket.
  • Add Sodium bicarbonate powder packet supplied by the supplier. Stir well with a wooden rod till entire powders dissolved.
  • Pour this solution into the outer vessel.
  • Clean the inner vessel.
  • Take one litre of watering a bucket add aluminium sulphate powder as supplied by supplier. Stir well till entire powders dissolved.
  • Pour this solution into the inner vessel.
  • Gently lower the inner vessel into the outer vessel without spilling out any solution it.
  • Clean the rubber washer and place it in position.
  • Place T-Handle in the down position. Slightly grease the threads before screwing up the cap.

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