Fire extinguishers are our silent heroes when it comes to fire protection. But what exactly is inside these handy devices that can save lives in an emergency? In this article, we take a look at the structure of a fire extinguisher.
he general structure of a fire extinguisher
A fire extinguisher basically consists of the following components:
- Tank: The cylindrical tank of a fire extinguisher is typically made of red sheet steel.
- Extinguishing agent: The heart of every fire extinguisher is the extinguishing agent. Depending on the type of fire, different extinguishing agents are used, including water, foam, powder or carbon dioxide.
- Safety pin or bar: The safety pin is intended to prevent the accidental discharge of extinguishing agent. It must be pulled out before the extinguisher is used.
- Riser pipe: The riser pipe guides the extinguishing agent to the extinguishing hose and the extinguishing nozzle.
- Extinguishing hose & nozzle
The differences in fire extinguisher design
The fire extinguisher design also differs depending on the type. In a rechargeable fire extinguisher, the propellant gas and the extinguishing agent are stored separately. A rechargeable fire extinguisher also has the following components:
- Propellant bottle: The propellant bottle contains the propellant (gas), which is only released when the rechargeable extinguisher is activated.
- Lever or firing head fitting: This is used to activate the rechargeable extinguisher so that the propellant bottle is pierced and the propellant gas is released.
- Extinguishing gun: The extinguishing gun can be used to control the discharge of the extinguishing agent.
Good to know: There are also rechargeable fire extinguishers that hold the extinguishing agent (foam) in a separate cartridge.
The extinguishing agent is therefore only mixed with the water in the container when the extinguisher is activated. This makes maintenance and disposal easier and more environmentally friendly.
In contrast, the propellant gas and the extinguishing agent are stored together in the container of a permanent pressure fire extinguisher. The extinguisher is constantly under pressure, so it is immediately ready for use without the fire extinguisher having to be activated.
A permanent pressure fire extinguisher also has the following components.
- Pressure lever: This is used to discharge and dose the extinguishing agent.
- Pressure gauge: A pressure gauge is attached to the fire extinguisher to monitor the pressure in the container. This allows the user to see whether the fire extinguisher still has sufficient pressure for use.
CO2 fire extinguisher setup
The design of CO2 fire extinguishers differs from classic rechargeable and permanent pressure fire extinguishers, which use foam, powder or water. With CO2 fire extinguishers, the extinguishing agent also serves as a propellant gas.
In addition, CO2 fire extinguishers are equipped with a funnel-shaped nozzle or a snow pipe instead of an extinguishing hose with an extinguishing nozzle or gun.