Fire extinguisher is a kind of active fire fighting equipment, which is usually used to put out or control small fire in emergency. It does not apply to out of control fires, such as those that have reached the ceiling, endanger the safety of users (i.e., there is no escape route, smoke, explosion risk, etc.), or require other expertise to prevent fires. Fire department. Typically, the extinguisher consists of a hand-held cylindrical pressure vessel containing reagents that can be discharged to extinguish the fire. There are also fire extinguishers made of non cylindrical pressure vessels, but they are not common.

Pressure storage fire extinguisher made of oval brand fire products

In the United States, fire extinguishers in all buildings except houses usually need to be maintained and inspected by a fire service company at least annually. Some jurisdictions require more frequent service for fire extinguishers. Service personnel place a label on the fire extinguisher to indicate the type of service performed (annual inspection, replenishment, new fire extinguisher).

British fire extinguisher with ID sign, call point and fire action sign

There are two types of fire extinguishers: accumulator type and box type. In the stored pressure unit, the fire extinguishing agent and the fire extinguishing agent are stored in the same chamber. Depending on the reagent used, different propellants are used. For dry chemical extinguishers, nitrogen is usually used. Water and foam fire extinguishers usually use air. The storage fire extinguisher is the most common type. Cartridge operated extinguishers contain exhaust gas in a separate cartridge that will be punctured prior to discharge to expose the propellant to the extinguishing agent. This type is not common, mainly used in areas such as industrial facilities, and its use is higher than the average level. Their advantages are simple and rapid replenishment, which enables the operator to discharge the fire extinguisher in a reasonable time, replenish and return to the fire. Unlike the storage pressure type, these extinguishers use compressed carbon dioxide instead of nitrogen, although nitrogen cylinders are used on low temperature (- class 60) models. In the United States, cartridge operated extinguishers have two types of dry powder and dry powder. In other parts of the world, they also have water, humectant, foam, dry powder (ABC and B.C.) and dry powder (D).

Wheeled fire extinguishers and signs in car parks

Fire extinguishers are also divided into hand-held and wheeled (also known as wheeled fire extinguishers). The hand-held fire extinguisher weighs from 0.5 to 14 kg (1.1 to 30.9 lbs), so it is easy to carry by hand. Devices mounted on trolleys usually weigh more than 23 kg (51 lb). These wheel models are most commonly used in construction sites, airport runways, heliports, and wharves and wharves.