Looking for a fire extinguisher? Equipping your office or home with a fire extinguisher is one of the most essential steps in creating a safe and secure environment for your family and employees. Fire extinguishers are our first line of defense in case of a fire breakout.
Although it is not as effective in putting down a full-scale fire, it is highly effective in stopping a sudden breakout. In other words, an extinguisher is instrumental in putting down a fire before it wages out of control. However, buying an extinguisher is not as simple as that. Before buying one must understand the type and functioning, Here we look at one of the most common type of extinguishers — dry powder fire extinguishers.
What is a dry powder fire extinguisher?
To understand the extinguisher, we have to first understand the nature of fire. Although all fires may seem the same, in truth each fire has its own character which is decided by what starts and sustains it. Accordingly, we divide fires in different types or classes. These are:
Class A – Fires that involve solid materials like textileswood, orpaper.
Class B – Fires that involve flammable liquids,like petrol, oilsor diesel.
Class C – Fires that involve gases.
Class D – Fires that involve metals.
Class E – Fires that involveelectrical apparatus.
The classification is devised so as to decide the firefighting agent. This is because not all agents are effective against all kind of fires. For instance, while water used in Class A fires works perfectly against textiles and wood, it can be damaging in Class E fires that involve electrical apparatus. Naturally, a multi-purpose extinguisher would be ideal and the dry powder fire extinguisher comes the closest to that.
A dry powder fire extinguisher uses dry chemical to put out a fire. It is used in Class A, B and C fires. Although it is also effective Class E fires, it is not ideally suited to it. This is because it leaves a residue which is not desirable when dealing with electrical apparatus. You can distinguish a dry powder extinguisher by it’s labeling. These extinguishers are clearly labeled.
Where is it used?
There are two types of dry powder extinguisher: ABE type and BE type. ABE type are effective against Class A, B and E fires. BE type is effective against Class B and E. These extinguishers are actually one of the most effective with the broadest range in their effectiveness. In fact, most places are covered by dry powder extinguisher, whether office, home or factory.
How does it work?
Like most extinguishers dry powder extinguishers work by taking out the oxygen from the fire triangle. Most dry powder extinguishers use a chemical known as called monoammonium phosphate. When it is used, the emitted dry powder reacts with the fire. The heat the particles to expand andinhabit the fire. In the process it pushes out the oxygen in the surrounding, effectively smothering the fire! In the BE type of extinguisher, the particles do not get enough heat to extinguish the fire.
Things to remember:
Just buying an extinguisher is not enough. There are some directions that one must always follow to ensure complete fire preparedness. These are:
- Refilling: Every time the extinguisher is used, it must be refilled or recharged. While this is true for all extinguishers, dry powder extinguisher loose the pressure very fast because the powder often gets stuck in the valve.
- Dry powder dust: The extinguisher works by smothering the fire with white powder. This also means that the whole space will be covered in this dust like powder. This means extensive clean-up afterwards!
- Beware of the machines: The dust can be harmful to machinery. Hence, it is not always recommended for electrical equipment.
- Regular servicing: A dry powder extinguisher must be serviced regularly. Without this the powder may settle at the bottom of the cylinder and become compact. This will hamper its functioning when required.
- Be fire ready: Even when you have the correct extinguisher on the premises, it is important that all your staff and family gets the proper training on how to use it.
Dry powder fire extinguishers are the most versatile type of extinguisher which can be used against Class A, B and E fires. However, before using it, it is important that one understands its usage and limitations.