A fire extinguisher is a device used to extinguish a small fire. It consists of a cylinder in which a limited quantity of extinguishing agent is put under pressure. There are also fire extinguishers with a pressure cartridge that must first be activated (punched in) by means of hitting a red button at the top of the fire extinguisher. The extinguishing agent can be sprayed onto the fire through an opening.
A fire extinguisher is suitable for one or more fire classes. A fire extinguisher roughly consists of a pressure vessel, a fire-extinguishing agent and a propellant. Without propellant in the pressure vessel, the extinguishing agent cannot come out of the extinguisher.
Some extinguishers therefore have a pressure gauge on top of the extinguisher. This shows whether the pressure of the propellant is still sufficient to activate the extinguisher.
There are roughly two types of fire extinguishers, depending on their function:
- Pressure-stored extinguishers with a pressure gauge.
- Cartridge-operated extinguishers that are not under permanent pressure with an internal or external pressure cartridge (must be put under pressure by the user with an impact button). These extinguishers do not have a pressure gauge.
There are different types of fire-extinguishing agents, each with its own characteristic properties.