A fire extinguisher, flame extinguisher, or simply an extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user (i.e., no escape route, smoke, explosion hazard, etc.), or otherwise requires the expertise of a fire department. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire.
There are two main types of fire extinguishers: stored pressure and cartridge-operated. In stored pressure units, the expellant is stored in the same chamber as the firefighting agent itself. Depending on the agent used, different propellants are used. With dry chemical extinguishers, nitrogen is typically used; water and foam extinguishers typically use air. Stored pressure fire extinguishers are the most common type. Cartridge-operated extinguishers contain the expellant gas in a separate cartridge that is punctured prior to discharge, exposing the propellant to the extinguishing agent. This type is not as common, used primarily in areas such as industrial facilities,
where they receive higher-than-average use. They have the advantage of simple and prompt recharge, allowing an operator to discharge the extinguisher, recharge it, and return to the fire in a reasonable amount of time. Unlike stored pressure types, these extinguishers use compressed carbon dioxide instead of nitrogen, although nitrogen cartridges are used on low temperature (-60 rated) models. Cartridge operated extinguishers are available in dry chemical and dry powder types in the U.S. and in water, wetting agent, foam, dry chemical (classes ABC and B.C.), and dry powder (class D) types in the rest of the world.
Class E has been discontinued, but covered fires involving electrical appliances. This is no longer used on the basis that, when the power supply is turned off, an electrical fire can fall into any of the remaining five categories.
Fire extinguishers are typically fitted in buildings at an easily-accessible location, such as against a wall in a high-traffic area. They are also often fitted to motor vehicles, watercraft, and aircraft – this is required by law in many jurisdictions, for identified classes of vehicles. Under NFPA all commercial vehicles must carry at least one fire extinguisher, with size/UL rating depending on type of vehicle and cargo (i.e. fuel tankers typically must have a 9 Ltr or Kg, while most others can carry a 2 or 1 kg. The revised NFPA created criteria on the placement of “Fast Flow Extinguishers” in locations such as those storing and transporting pressurized flammable liquids and pressurized flammable gas or areas with possibility of three dimensional class B hazards are required to have “fast flow” extinguishers as required by NFPA. Our Company provides the services for the supply & installation of the fire extinguishers as NFPA and National Building Code 2005.
This technology is not new, however. In the 1800s, glass fire grenades filled with suppressant liquids were popular. These glass fire grenade bottles are sought by collectors. Some later brands, such as Red Comet, were designed for passive operation, and included a special holder
with a spring-loaded trigger that would break the glass ball when a fusible link melted. As was typical of this era, some glass extinguishers contained the toxic carbon tetrachloride.
Fire extinguisher requires regular maintenance by a competent person to operate safely and effectively, as part of fire safety legislation. Lack of maintenance can lead to an extinguisher not discharging when required, or rupturing when pressurized. Deaths have occurred, even in recent times, from corroded extinguishers exploding.
Basic Service : All types of extinguisher require a basic inspection annually to check weight, correct pressure (using a special tool, not just looking at the gauge) and for signs of damage or corrosion, cartridge extinguishers are opened up for internal inspection & check weighing of the cartridge, labels are checked for legibility, where possible dip tubes, hoses and mechanisms checked for clear free operation.
Extended Service : Water, Wet Chemical, Foam & Powder extinguishers require every five years a more detailed examination including a test discharge of the extinguisher and recharging; on stored pressure extinguishers this is the only opportunity to internally inspect for damage/corrosion. By recharging fresh agent is used as they all have a shelf life, even water goes foul inside an extinguisher; Note: extinguishers should be percentage tested according to total number of units in any given area. Some extinguishers contain pressure in excess
of 1.38 MPa (200 psi) and this internal pressure over periods of time affects each brand & make differently depending on their placement & location.
Overhaul : CO2 extinguishers, due to their high operating pressure, are subject to pressure vessel safety legislation and must be hydraulic pressure tested, inspected internally & externally and date stamped every 10 years. As it cannot be pressure tested a new valve is also fitted. If replacing any part of the extinguisher (valve, horn, etc.) with a part from another manufacturer then the extinguisher will lose its fire rating. This may invalidate insurance, as would incorrect or inadequate servicing if it were to be found.
Our Company is also engaged in refilling of Fire Extinguishers. After basic inspection, if any fire extinguisher observed to be in a condition in which it requires immediate refilling or recharging then our highly expertise team provide services in refilling of Fire extinguishers. We also have a facility to get the hydraulic testing along with the refilling of fire extinguishers.
ABC Dry Powder (Monoammonium Phosphate) for ABC type Fire Extinguishers
AFFF ((aqueous film forming foam) for Mechanical Foam or AFFF type Fire Extinguishers
AFFF used on A and B fires and for vapor suppression. The most common type in portable foam extinguishers. It contains fluoro tensides which can be accumulated in the human body. The long-term effects of this on the human body and environment are unclear at this time.
Sodium Bicarbonate Powder for DCP type Fire Extinguishers
Sodium bicarbonate, “regular” or “ordinary” used on class B and C fires, was the first of the dry chemical agents developed. In the heat of a fire, it releases a cloud of carbon dioxide that smothers the fire. That is, the gas drives oxygen away from the fire, thus stopping the chemical reaction. This agent is not generally effective on class A fires because the agent is expended and the cloud of gas dissipates quickly, and if the fuel is still sufficiently hot, the fire starts up again. While liquid and gas fires don’t usually store much heat in their fuel source, solid fires do. Sodium bicarbonate was very common in commercial kitchens before the advent of wet chemical agents, but now is falling out of favor, as it is much less effective than wet chemical agents for class K fires, less effective than Purple-K for class B fires, and is ineffective on class A fires. White or blue in color.
APW (Air Pressurized Water) for Water Co2 type fire Extinguisher APW (Air pressurized water) cools burning material by absorbing heat from burning material. Effective on Class A fires, it has the advantage of being inexpensive, harmless, and relatively easy to clean up. In the India, APW units contain 2.5 gallons (9 liters) of water in a tall, stainless steel cylinder.
Co2 for Co2 type Fire Extinguisher CO2, a clean gaseous agent which displaces oxygen. Highest rating for (20 pound) portable CO2 extinguishers is 10 B:C. Not intended for Class A fires, as the high-pressure cloud of gas can scatter burning materials. CO2 is not suitable for use on fires containing their own oxygen source, metals or cooking media. Although it can be rather successful on a person on fire, its use should be avoided where possible as it can cause frostbite and is dangerous to use as it may displace the oxygen needed for breathing, causing suffocation.
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