Types of Fire Extinguisher
Each fire extinguisher has its own symbolic notation, that is a special geometric symbol to make it easier for you to identify the extinguisher type. They also have some additional information necessary in case of this or that class of fire fighting.
- Class A fire extinguishers, for example, have the green triangle on them and also the special numerical rating, showing the amount of water this extinguisher holds and the amount of fire it is able to extinguish.
- Class B fire extinguishers are marked with the red square and have the numerical rating indicating the approximate area of fire (in square feet) it is able to extinguish.
- Class C fire extinguishers are marked with the blue circle, but they don’t have any numerical rating. As a rule they contain the non-conductive extinguishing agent, because they are often used for electrical fire fighting.
- Class D fire extinguishers have the yellow decagon on them and are mostly regarded as the part of chemical laboratory firefighting equipment. They also don’t have any numerical rating on them.
There are also class K fire extinguishers, marked with the black hexagon. They are intended for the fighting the fire, caused by any cooking oils, fats or trans-fats combustion and are highly recommended for restaurant or cafeteria kitchens.
Classification of fire extinguisher by Contents nature based
There is also another fire extinguisher classification based on their contents nature. According to this classification there are water, foam, dry-powder and CO2 fire extinguishers.
- Water or APW (Air pressurized water) fire extinguishers is as a rule recommended for class A fire fighting and are effective in the case of wood, paper or plastic ignition. Their operating principle is based on the reducing the temperature of the burning materials below their ignition temperature. High air pressure with water, are mostly used this type fire extinguishers.
- Dry powder fire extinguishers as a rule contain some powder based agent, able to break the chemical chain reaction, sustaining the fire. There are monoammonium phosphate (“tri-class” or “multipurpose”) units, belonging to this group, that are recommended for use in case of class A, B, and C fires, sodium bicarbonate fire extinguishers, that prevent the oxygen reaching into the fire, discharging the carbon dioxide and use on class B and C fires, or potassium bicarbonate (also famous as aka Purple-K) extinguishers, popular in oil and gas industry for their powerful effect in case of a class B or C fires.
- Carbon dioxide (CO2) and other clean agents containing fire extinguishers operate almost on the same principle that the dry-powder extinguishers do. They inhibit the chemical chain reaction, sustaining the fire, but have one great advantage here – they don’t leave any residue after the discharge, what makes them invaluable as the part of firefighting equipment for offices. The fire extinguishers of this type as a rule contain halo (a gaseous agent, inhibiting the chemical reaction of fire and effective in case of a class B or C fires) or CO2, able to reduce the oxygen around the fire area. They can also contain the mixtures of inert gases, like Inergen and Argonite.
Now we are studying fire extinguisher types but firstly be knowing types of fire.
Types of Fire
If we speak about the nature of fire, we must always keep in mind that it is the chemical reaction that is possible in the case when fuel and oxygen are brought together with the heat, sufficient for the combustion process. This dangerous combination is able to cause fire. If you remove one of these dangerous components, the process of combustion is no more possible and fire ends. This is the basic principle for the competent fire fighting, as well as for the right fire extinguisher choice.
The fires are subdivided into 4 main classes: A, B, C or D (on the basis of the nature of combustible or inflammable materials that caused the fire in this or that case).
- As a rule, class A fires are the fires of solid materials of organic nature (such as wood, paper, cardboard, furniture and most plastics).
- The class B fires are, as a rule, fires of the flammable or combustible liquids, such as petrol, oil, paint, kerosene, grease, cooking fats and any others.
- The class C fires are the fires of the inflammable gases, like propane, butane, acetylene and so on.
- And, finally, class D fires are fires of burning metals like aluminum, magnesium, titanium, potassium or sodium.
As for electrical fires, they mostly refer to the class C, as they include the combustion of electrical equipment, such as appliances, wiring, circuit breakers and outlets, though they can also be of A, B or D type.
So, if you know the type of fire possible in these or those premises, it is for sure easier for you to choose the appropriate fire extinguisher.
Fire Extinguisher Inspection and Maintenance
The fire extinguisher container has a limited period of exploitation notwithstanding the fact of non-usage. The fire extinguisher content is prone to lose inside pressure, inner sides of it are able to experience corrosion or rust in case of containing liquid, and if having constant high pressure, container seams may lose their hermetization.
The container seals may be damaged by incorrect storage conditions or under stand-by mode storage, valves have a feature to jam and after that the fire extinguisher becomes a fire safety knocked apparatus as a part of the fittings and fixed asset of a certain building.
Annual Maintenance of Fire Extinguishers
Fire extinguishers in annual basis (or more frequently, if the extinguisher is used in an environment with high fire risk or corrosion) shall be held by a competent person, who is obliged to inspect or check every single extinguisher and provide data for what amount of them needs to be replaced, execute pressuring and if there are those achieved the limit of their operational life.
All Office are should be inspected on a monthly basis
Under inspection, we mean simple visual investigation and check, and we believe this easy procedure will not take much of your time, as it should be done once a month, but it can save lives and money, and it should be the responsibility of every employee.
- Every fire extinguisher should stand properly at respective aria or wall brackets along with free access to it. One should be assured that every fire extinguisher hanging/standing brackets is secured and firmly; the Signage is not damaged and clearly seen by the staff; this is necessary for the staff to see the extinguisher in case of emergency. In the event of any damage, leak of unclear Signage it should be replaced at once.
- The pressure gauge should be checked. The needle of the gauge should remain in green zone. If it is in red zone, there are two ways: either to re-pressurize the extinguisher, or substitute it with a new one.
- All seals on fire extinguisher should not be damaged or torn; safety pin is in its proper place and secured by special evident seal or OK mark. In case of cleaning, one should carefully remove the dust from nozzle, valves, gauge areas (you can also use vacuum cleaners), or if the area is oriented to be particularly dusty or dirty, provide special fire extinguisher covers.
- Every fire extinguisher should be checked for any dents, rust places, or leak. If you noticed any of it, replace the fire extinguisher immediately, and remove the old one safely. In case if the extinguisher is seriously damaged, we strongly advise you NOT to replace it yourself as the container may explode. Call in a specialist who will do the job safely.
- Labeling should be clearly visible. Some manuals say about shaking small powder extinguishers to prevent inside from turning into cake mess. In reality you should just hold the unit upside down close to your ear and hear the falling of loose powder. You shouldn’t try it with large containers.
- And the last, but not least. You should check for the location near extinguisher and be assured nothing prevents you from urgent access to it in case of emergency.
Recycling of Fire Extinguishers
Several companies dealing with extinguisher maintenance, work with refilling and renovating companies as the majority of extinguisher details can be recycled. All extinguisher bodies are inspected, and if there is sound, it is used again, if not – it is hacked in two, or scrapped to escape further usage.
Thanks to http://www.allfireextinguishertypes.com/