Fire extinguishers are indispensable fire-fighting tools that have been safeguarding various commercial, domestic, and food places since 1723. Due to the containment of special firefighting agents within the high-pressure cylinders, it efficiently films the fire flames, cuts the oxygen supply, smoothens the bursting flames, and eventually puts out the fire.
In this comprehensive blog post, we will explore different fire extinguisher types and learn which are suitable for different fire types. Stay tuned!
A] Introduction to Fire Extinguisher
Patented in 1723 by Ambrose Godfrey, the fire extinguisher is a portable device that is used to extinguish small fires. It works by spraying special agents over the burning fire which cools down the flame by cutting out the oxygen supply and smoothing the fuel property. To store these fire-fighting agents, such as carbon dioxide, water, foam, dry powder, and wet chemicals, high-pressure cylinders are used. These cylinders are built with robust materials and security measures to withstand these highly reactive agents under suitable pressure. Fire extinguisher cylinders are made from high-strength steel and come with a storage capacity of 1.5 to 220 litres along with 150 to 300 bar filling pressure.
B] Exploring the Common Types of Fire Extinguishers
1. Water Fire Extinguishers
Water fire extinguishers are the most common fire extinguishers used for putting out class-A fires which usually originate from organic matters such as coal, cloth, paper, and wood. It contains water, additives, and filming agents inside a robust cylinder. However, water fire extinguishers should not be used in electrical fires, fires that originate from petrol or paint, and fires that are flared up due to gases like methane, butane, and LPG. It is coloured red and labelled in white.
2. Foam Fire Extinguishers
Foam fire extinguishers are commonly used fire extinguishers that utilise a combination of water and Aqueous Film Forming Foam (AFFF) to put out class A and B fires. It works by sealing a flammable vapour and smoothing the fire. They are usually lighter in weight, non-toxic in nature, and don’t damage the materials except electrical equipment. However, foam fire extinguishers should not be used to extinguish cooking fires or flammable gas fires. In India, this common type of fire extinguisher is coloured in cream labels.
3. Dry Powder Fire Extinguishers
Dry powder fire extinguishers, also known as multi-purpose fire extinguishers, contain fire-fighting agents like sodium bicarbonate, potassium bicarbonate, or mono ammonium phosphate. They are widely used in putting out different types of fires except for fires inside the enclosed space. However, it is not recommended to use a dry fire extinguisher in case of cooking fires, electrical fires over 1000 volts, enclosed-space fires, or fires ignited by flammable metals (i.e., alkali metals, magnesium, titanium, zirconium, aluminium, and zinc).
4. CO2 (Carbon Dioxide) Fire Extinguishers
Carbon dioxide fire extinguishers contain high-pressure carbon dioxide liquified gas within robust firefighting cylinders. These types of fire extinguishers are usually used in putting out electrical and liquid fires. It works by cutting the oxygen supply gradually and cools down the flame. However, they are not recommended for extinguishing fires ignited by oil, grease, or chip pan. In India, they are labelled in black.
5. Wet Chemical Fire Extinguishers
Wet chemical fire extinguishers contain potassium which is stored in high-pressure cylinders to maintain the desired pressure. It is generally used to put out Class-K fires, such as kitchen fires, oil and grease fires, or animal fat fires. It works by putting the soapy-like films over the fire flame, which causes to smoothen the bursting fire. They are particularly installed within the kitchen and garbage area to mitigate the risk of fire outbursts. Wet chemical fire extinguishers are coated with yellow labels.
6. Class K Fire Extinguishers
Class K fire extinguishers contain wet chemicals like potassium carbonate, potassium acetate, or potassium citrate mixed with cooking grease. A combination of these fire-fighting agents creates oily blankets over fire flames and thus smoothens the bursting fire. These extinguishing agents are stored in highly robust cylinders to maintain their optimal pressure. These firefighting extinguishers are used to douse combustible cooking oils, fat oils, and vegetable oils. Class K fire extinguishers are coated in silver or chrome labels.
7. Clean Agent Fire Extinguishers
Clean agent fire extinguishers contain firefighting agents, such as HFC 236fa, carbon dioxide, Novec 1230, and FK-5-1-12. These clean firefighting agents are stored in a pressurised cylinder under suitable pressure. It works by reducing the oxygen supply to the fire, cooling the fire flame, and fogging the area to put out the bursting fire. They are usually used in dousing Class-A, B, C, and electrical fires. They are coated in purple labels in India.
C] Suitable Fire Extinguishers for Different Fire Types
1. Class A Fire
Class A fires, also known as ordinary fires, are those types of fire that usually ignites from combustible materials, like paper, wood, rubber, plastic, and clothes. To put out these fires, water and foam fire extinguishers are used. A sturdy and high-pressure cylinder is required to contain its firefighting agents at optimal pressure.
2. Class B Fire
A fire that ignites from flammable liquid, gas, gasoline, grease, kerosene, oil, alcohol, ether, propane, and butane is known as a Class B fire. Ignited fires from these flammable matters can efficiently be put out using dry powder, foam, and carbon dioxide fire extinguishers.
3. Class C Fire
Class C fire is a fire type that ignites from electrical equipment, such as electrical and electronic appliances, wiring, and circuit breakers. To put out a Class C fire, dry powder and carbon dioxide fire extinguishers are used.
4. Class D Fire
When a fire ignites from flammable metals, like aluminium, titanium, magnesium, lithium, zirconium, sodium, potassium, uranium, plutonium, and calcium, it is classified as a Class D fire. To extinguish these fire types, a dry powder fire extinguisher is used.
5. Class F Fire
Class F fire is a fire that involves cooking oil and fat. These flammable materials have auto-ignition properties which pose the risk of igniting itself at 340 degrees Celsius without any external firing agents. To handle or douse the Class F fire, a wet chemical fire extinguisher is used.
6. Class K Fire
Class K fire is a fire that involves flammable cooking oil, fat, and grease. The occurrence of Class K fire is mostly seen within the area of commercial kitchens, restaurants, bakeries, and food trucks. Class K and wet chemical fire extinguishers are used to put out the Class-K fires.
Conclusion
From households to giant commercial places, fire extinguishers are serving their life-saving role in many areas. However, it is essential to use suitable fire extinguishers by assessing the flammable or combustible materials that are being used within the vicinity. In addition, check the robustness and fitting measures of the fire extinguisher’s cylinders to ensure they work properly at the time of use.
Rama Cylinders is one of the world’s largest NGV cylinders manufacturers, offering extremely robust and highly secured cylinders for firefighting applications. From houses to offices and Industrial plants, we have delivered countless numbers of cylinders (capacity of 1.5 to 220 litres along with 150 to 300 bar filling pressure) for firefighting applications to our domestic as well as international clients. We specialise in customising cylinders as per the requirements. Contact us for information.