Portable Fire Extinguishers
Portable Fire Extinguishers are hand-held cylindrical pressure vehicles containing fire extinguishing agents which can be discharged to extinguish a fire. Fire Extinguishers are predominantly used to contain small fires, in emergency situations.
There are broadly two kinds of fire extinguishers. These are Stored Pressure Fire Extinguishers and Cartridge operated extinguishers. In the stored Pressure Fire Extinguishers, the expellant and the agent are stored in the same cylinder.
The different agents used in the fire extinguisher may need different propellants. While Dry chemical extinguishers usually use nitrogen or dry air as a propellant, Water and foam extinguishers generally use air.
Cartridge-operated extinguishers contain the expellant gas in a separate cartridge that is punctured before the discharge, exposing the propellant to the extinguishing agent. Unlike stored pressure types, these extinguishers utilize compressed carbon dioxide instead of nitrogen, although nitrogen cartridges are used on low temperature models.