Fire extinguishers are cylindrical reservoirs made of metal that contain agents suitable for firefighting in an early stage, such as water, chemical powder, carbon dioxide or foam. In addition to the product used to extinguish the fire, inside the extinguisher there is usually a small reservoir that contains a compressed substance, usually nitrogen. When the extinguisher handle is activated, nitrogen is released into the reservoir containing the extinguishing agent. As soon as the nitrogen occupies the largest reservoir, the extinguishing agent is expelled outwards through the extinguisher’s discharge hose.
