The content of the article
- Types of fire extinguishers
- Terms and conditions of use
- How a fire extinguisher works
- Procedure for using a fire extinguisher
- Powder Fire Extinguisher Rules
- Carbon dioxide fire extinguisher instruction manual
- Air foam application
The main fire extinguishing and fire safety tool of any facility is a fire extinguisher. When a small fire occurs, it is easier to cope with the problem that has arisen on your own, especially since it is not always advisable to cause a fire brigade due to the smoke of one electrical appliance. Regardless of the reaction of firefighters, there is always a risk that by the time of their arrival a fire can cause significant damage. To feel confident when a fire hazard occurs, check out the existing types of fire extinguishers.
Types of fire extinguishers
In the narrow sense of the word, a fire extinguisher is a container that contains the active substance necessary to isolate the ignition source from the catalyst of the combustion process, i.e. oxygen. When choosing a suitable fire extinguishing device, you need to evaluate what potential sources of ignition are in your home, office, or other facility. Based on this, you need to make a specific choice, for example, an air-foam device is not suitable for extinguishing electrical appliances.
The principle of operation for all types of fire extinguishers is similar: when the valve is opened, due to the pressure difference inside and outside the cylinder, a jet is formed that extinguishes the flame. 90% of the devices are presented in the form of cylinders that are equipped with a trigger mechanism and a nozzle specially designed to form a jet from the substance that is contained inside. Keep such a device in the office, car or other place should always be, because his help at the right time can be invaluable. Fire extinguishers are classified according to several criteria:
- Way to move. In some cases, a conventional portable device, which is a fire extinguisher weighing no more than 20 kg, is not enough to eliminate a fire hazard. They are relevant for small offices, rooms. There are still mobile and stationary models. The first have a mass of 20 to 450 kg – they are relevant for subways, gas stations, etc. The second, in fact, are similar to an automatic fire extinguishing system.
- The principle of operation. On this basis, manual and automatic devices can be distinguished. The latter work independently without human intervention – it is recommended to install them in places of increased danger and where the person simply does not have time to react to a fire. Systems of this type include the fire extinguishing device itself and a special sensor that responds to smoke.
- Type of trigger device. In this case, pistol devices are distinguished that are equipped with a valve, squib or start-up, depending on pressure.
- The presence of additional equipment. Some models of fire extinguishers can be equipped with an additional can of catalyst.
The main sign by which fire extinguishers are classified is their composition. The characteristics and features of the device depend on it to a greater extent. In this case, carbon dioxide, powder, water and air-foam models are distinguished. More about their features:
- Water. Water or various solutions based on it are the cheapest (almost free) type of extinguishing agent. Often the capacity of extinguishers designed for liquid contents is filled with finely divided water and special extinguishing agents. They can be used to localize or eliminate Class A fires – burning solid materials, substances. They are not suitable for extinguishing electrical appliances, substances that enter into exothermic chemical reactions with water, and very hot, straightened items.
- Carbon dioxide. Carbon dioxide (carbon dioxide) is one of the most effective types of extinguishing agent, which cools the combustion zone and phlegmatizes (dilutes) the gas. This type of device is necessary to eliminate fires of electrical appliances with an operating voltage of not more than 1000 V and automobile engines. In addition, it is suitable for extinguishing flammable liquids and some other materials and substances. Car owners often face a carbon dioxide fire extinguisher, as the presence of such a device is a necessity for vehicles. It is forbidden to use to eliminate the ignition of those substances that burn in the absence of oxygen. Carbon dioxide is not suitable for extinguishing a burning person..
- Airy foam. This type of device is used to extinguish flammable and flammable liquids, solid materials. The nozzle design provides the supply of air-mechanical foam of low and medium multiplicity. The efficiency of using this device increases significantly when using fluorinated film-forming foaming agents as a charge. The disadvantages are the possible freezing of the contents of the tank at sub-zero temperatures, high corrosion activity and unsuitability for extinguishing equipment that is energized. In addition, such a fire extinguisher is not suitable for extinguishing molten, highly heated substances and those that react with water.
- Powder They are useful when igniting electrical appliances, installations with an operating voltage of up to 1000 V, solids. Do not extinguish liquid and gas without a powder device. It is the most versatile in the operating temperature range and scope. Some powder fire extinguishers can be used in moderate climatic conditions at a temperature of -40 ° C to + 50 ° C. They are not designed to extinguish a fire of alkaline earth and alkali metals and other materials, the combustion of which can be maintained without air.
Terms and conditions of use
There are certain rules for the operation of fire extinguishers, which must be observed regardless of what type of fire extinguishing device is used. Adhering to them, you can make the use of this device more effective and safe for yourself. More details:
- Direct the bell directly at the fire and do not extinguish, being at a great distance from the fire. The optimum distance is the one that corresponds to the minimum length of the jet – you can find it on the label.
- Do not forget about the check or valve that each cylinder is equipped with..
- Consider weather conditions. The wind should blow in the back, but strong currents of air will only fan the fire. In this case, it is advisable to work with several fire extinguishers from different sides..
- The fight against fire must begin from the near edge of the fire. As it calms down, you can move on..
- Do not rush during flame extinguishing. Extinguish without sharp jerks, gradually.
- When eliminating a fire in electrical installations, maintain a safe distance of about 1 m..
- When extinguishing objects that are under electric shock, extinguishing agent must be supplied in parts. At the same time, observe a break of 5 seconds.
- Extinguish oil formulations from below..
- When using a carbon dioxide fire extinguisher, it is recommended to wear gloves to avoid all kinds of injuries..
- Use all the fire extinguishing devices that you only have. It is advisable to use them at the same time if there are free hands.
- Monitor the condition, storage conditions and expiration date of the device so that it is not inoperative at the right time.
Storage methods for a fire extinguisher depend on the size of the container. Small devices can be hung on the wall using special mounts. For large tanks, whole fire cabinets are designed. During the placement of the fire extinguishing device, an initial inspection should be carried out to identify defects. Do not forget that the fire extinguisher bottle must have a certificate of conformity and a passport. In addition, such a device needs protection from external factors that may affect operability. These include:
- dampness in the room;
- thermal radiation;
- vibrations that can damage the container;
- low temperature in the room (place foam and water devices in heated places);
- exposure to direct sunlight.
How a fire extinguisher works
The basis of such a device is a durable metal cylinder. When you press the lever located in the upper part of the cylinder, the extinguishing agent is released outward under high pressure – almost the same as from an aerosol can. Structurally, the classic version consists of:
- cases with a tube;
- a hose;
- trigger mechanism;
- pressure gauge;
- Schroeder valve;
- plastic coasters.
A plastic siphon tube of the device leads from the bottom of the storage with the extinguishing agent to the nozzle. A spring-loaded valve closes the passage to this same nozzle, and in the upper part of the body there is a small container that is filled with compressed gas – for example, liquefied carbon dioxide. The function of the valve is to keep compressed gas from escaping.
When the lever is pressed, it exerts pressure on the drive rod, which actuates a spring-loaded valve to open the passage to the nozzle. At the bottom of the drive rod there is a sharp tip piercing a can of compressed gas. The latter, when exiting, displaces a fire extinguishing agent with a high pressure from the device’s balloon. The nozzle, as a rule, should be directed to the fuel, and not to the flame, not forgetting to move the jet.
Procedure for using a fire extinguisher
Each type of device for extinguishing fires has its own characteristics and nuances in use, but in general, we can distinguish a common sequence of actions for most options. General instructions for the use of fire extinguishers:
- Each extinguishing container is equipped with a seal or receipt. Before use, they must be removed..
- Then point the device hose to the fire. The approximate distance of the substance is about 3 meters.
- To provoke an extinguishing agent, press the special lever.
- A few seconds after the pressure is applied, the fire extinguisher will be fully operational, and you can begin to extinguish the fire.
Powder Fire Extinguisher Rules
A powder-filled fire extinguisher is suitable for extinguishing almost all fire classes. It can be of two types: pumped in and with a built-in pressure source. The advantage of both types lies in the ability to control the intensity of the jet and dose the powder. In the case of the pumped device, the powder under the influence of an inert gas (air, carbon dioxide or nitrogen) is fed into the hose, from where it enters the source of ignition and isolates its source from oxygen. Due to this, combustion will gradually stop. Instruction:
- Direct the nozzle of the hose of the container with extinguishing powder to a burning surface.
- Tear off the seal and pull out the check.
- Press the lever and begin to eliminate the source of ignition.
The peculiarity of the second type of powder device is the presence of an additional gas cylinder that creates pressure. The principle of its use is to use the energy of the generated gas to aerate the emission of powder. When the lever is pressed, the gas generator is triggered, due to which the working gas is released. In order to create the necessary pressure in the housing, it is necessary to wait at least 5 seconds. Rules for using this type of fire extinguisher:
- Tear and pull out a check.
- Raise the main lever to failure.
- Hit the button on the gas bottle.
- Point the hose nozzle to the fire.
- Press the main lever.
Carbon dioxide fire extinguisher instruction manual
A carbon dioxide fire extinguisher works according to this principle: CO2 rises to the bell during the opening of the valve – at the same time it immediately passes from liquefied form to solid. This process is accompanied by a sharp drop in temperature to -70 ° C. Upon contact, carbon dioxide blocks the fire’s access to oxygen, isolating the source of ignition from it. The combustion reaction without oxygen, as you know, is impossible. Rules for using a carbon dioxide fire extinguisher:
- Tear the seal.
- Pull out a check.
- Point the bell to the fire.
- Press the lever and proceed to eliminate the flame.
Check out the instructions for using a mobile carbon dioxide fire extinguisher, which is one of the most popular among this category. Actions with him are as follows:
- Gently unwind the rubber hose first.
- Then take a comfortable position to eliminate the fire..
- Remove the seal and turn the lever towards you to failure.
- Point the bell at the fire and proceed to eliminate it.
Air foam application
A feature of such a fire extinguishing device is the presence of a can of gas and nozzles. The first serves as a source of overpressure. Under the action of gas, the foaming agent inside the cylinder rushes to the nozzle, where it mixes with air, as a result of which foam is formed to eliminate the fire. Instructions for the use of fire extinguishers of this type are as follows:
- Tear off the seal and pull out the check.
- Point the cylinder nozzle at the fire.
- Press the button or lever for the optional spray can.
- Press the main lever and proceed to localize the fire.