Fire Extinguishers (Stored Pressure)

Additional Details

A fire 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 generated pressure. 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 are pressurized with air. Stored pressures are the most common types of fire extinguishers. Cartridge-operated extinguishers, contain the expellant gas in a separate cartridge that is punctured prior to discharge, exposing the propellant to the agent. These types as are 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 an reasonable amount of time. Unlike stored pressure types, these extinguishers utilize compressed carbon dioxide instead of nitrogen, although nitrogen cartridges are used on low temperature (-60 rated) models. Cartridge operated types are available in dry chemical and dry powder in the US and water, wetting agent, foam, and dry powder(ABC, BC, or D) in the rest of the world.