What is a fire extinguisher?
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The above if adhered and employed properly with good quickness it would be a game changer.
Fire extinguisher is an equipment comes under the portable type fire protection system. These equipment comes with a variety of its kind with different applications. A fire extinguisher are user friendly and once acknowledged about the method of employment it may prove as a major element in the salvage and saving human lives.
Operation hesitancy:-
Nowadays it has been observed that people sometimes due to their deficiency of the practical knowledge they find themselves lingering on the backseat of the life experience. Similar case happens with these equipments as well, despite being the most easiest thing to operate due to lack of knowledge people just don't have the reflexes to achieve the target in the case of an emergency and which may manifold into a massive incident.
PASS System:-
•The name of the system is made up of the initial letters based on the respective activities.
•It is the method of operating an extinguisher viz.,
P- PULL THE PIN.
A- AIM THE TARGET.
S- SQUEEZE THE GRIP NOZZLE.
S- SWEEP IT FROM SIDE TO SIDE.
Why is it so important to store?
Following points consist of the conspicuous reasons why is it so necessary to have an extinguisher:-
•The primarily save lives and property by extinguishing fire.
•They are portable and can be carried upto the desired place.
•They are cheaper.
•They are certainly light weight(based on the type and nature of the area.)
•They comes under the legislative restrictions.
•Prevents any lumpsum burst in the expenses.
•Prevents the compensation cost.
Disadvantages:-
•They lasts just for few seconds or minutes.
•They aren't meant to employ on the major fires.
•They (if not well maintained) won't be haing the calibre to operate or dispense the inherent media.
•May operate due to carelessness.
EXPELLANTS FOR FIRE EXTINGUISHERS
•Expellant
What is an expellant? It is an inert gas that provides the internal pressure in a fire extinguisher to expel the extinguishing medium e.g. Dry chemical powder, water, foam. The expellant for a stored pressure (STP) fire extinguisher is the gas inside the unit that pressurises the extinguisher. The expellant gas pressure is recorded on the STP units gauge. The cartridge operated type fire extinguisher has the expellant gas inside a cartridge which is released manually into the extinguisher when pressure is required to expel the extinguishing medium.
• Burst Pressure.
Low pressure fire extinguishers have a bursting pressure of not less than (55 Bars) 5500Kpa
•Stored Pressure Fire Extinguishers.
Nitrogen (N2) is extensively used for pressuring STP fire extinguishers as it is a dry gas and will not contaminate a dry powder extinguishing medium. It is also the cheapest of all the acceptable gases dictated by SANS1910.
N2 is transported in very high pressure cylinders (200 Bar) 20000Kpa and a pressure reducing regulator must be used to pressurise an STP fire extinguisher to its specified Internal pressure (normally 14Bars in S.A.) 1400Kpa.
Only fully trained servicemen shall pressurise an STP extinguisher with an N2 pressurising rig.
•Cartridge Operated Type Fire
Extinguishers.
CO2 gas is used to pressurise the cartridge of a cartridge type fire extinguisher but the CO2 gas will
only be manually discharged into the extinguisher when required, thus having no contact with the extinguishing medium until discharge of the medium is desired.
CO2 must not be used to pressurise an STP extinguisher for the following reasons:
1. CO2 is a wet gas even if the cylinder has no syphon tube and the pressure only is used. It will still contaminate dry powder.
2. Using this method means you are not using a pressure regulating device (required by SANS 1475 part one)
3. CO2 has a operating pressure varing from approx 47 Bars to 67 Bars(4700Kpa to 6700Kpa),
dpending on the CO2 cylinder temperature. (see burst pressure of a low pressure vessel)
CO2 is a wet gas and Dry Chemical Powder (DCP) is hydroscopic (attracts moisture), this causes the DCP to go lumpy or hard. An STP, DCP fire xtinguisher will then fail to operate successfully.
It can further be catogerized as:-
The following types of portable fire extinguisher are commonly found in workplaces (note that the classes of fires used here refer to the UK classification system outlined earlier):
· ~Water – suitable for Class A fires. Works by cooling the fire. Standard water extinguishers are not suitable for use on Classes B, D or F fires or live electrical equipment (risk of shock). Certain specialised water extinguishers are available for use on Class B and F fires.
· ~Carbon dioxide – suitable for Class B fires, especially fires involving live electrical equipment. Works by smothering the fire. Not suitable for use on Class D fires. Must be used with care because the body of the extinguisher gets very cold during use and can cause a freeze burn injury.
(Tap to see) Profound info about the foam.
· ~Foam – suitable for Class A and B fires. Works by smothering the fire, or by preventing combustible vapours from mixing with air.
(Tap to see) How to use a foam type extinguisher?
· ~Dry powder – suitable for all classes and use on live electrical equipment. Works by smothering the fire. Can be very messy.
(Tap for see) How dry chemical fire extinguisher works?
Colour coding of the fire extinguisher:-
1. Water (White)
Water is usually the first thing you think of for putting out fires. And water fire extinguishers are probably the most common. This fire extinguisher is red with white writing and label. It mostly works by cooling the fire to extinguish it.
This type of fire extinguisher is simple to use. However, water fire extinguishers are only suitable for class A fires, which are fires involving solids. Like burning wood, paper, plastics etc.
Water Mist
A recent development in the types of fire extinguishers is water mist. Also red with white labelling, this type of fire extinguisher looks similar to water extinguishers but has some different uses.
In addition to class A, water mist can also be used for class F (cooking fats and oils) fires. Because the fine mist doesn't conduct electricity, they can also be used on electrical (E) fires! Water mist extinguishers can also be used on class B (liquid) and C (gas fires).
2. Foam (Cream)
Foam fire extinguishers are red with a cream label. Foam extinguishers primarily work by smothering fires and starving the fire of the oxygen it needs to burn.
Like water extinguishers, they can be used on class A fires. Foam extinguishers are also used on class B fires. These are fires involving liquids, like petrol and paints.
3. Powder (Blue)
Dry powder fire extinguishers are red with a blue label. Like foam, the non-combustible powder smothers the fire. Unlike foam extinguishers, this type of extinguisher doesn't contain water so can be used on live electrical equipment.
Powder extinguishers can be used on class B (liquid), class C (gases), and class E (or electrical fires). They also have some limited use on class A fires. While a useful multi-purpose iextinguisher, power does have some downsides. Powder extinguishers are very messy when used. The use of this extinguisher can fill the air with powder causing visibility issues, and inhalation of powder. And, while it can be used on electrical equipment, power will enter equipment and can cause damage.
4. Carbon Dioxide (Black)
Carbon dioxide (CO2) extinguishers are red with a black label. You may also notice the nozzle on this type of extinguisher is a large cone shape. The carbon dioxide in this type of extinguisher replaces the oxygen in the air surrounding the fire, preventing combustion.
Carbon dioxide extinguishers are best used for electric (E) fires. They don't contain water and won't damage surrounding equipment like powder extinguishers. They can also be used on small class B (liquid) fires, but cooling effects on the liquid are limited and the fire may re-ignite after it has been extinguished.
√Refilling and hydrotesting:-
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