Sometimes there is also a gauge which indicates whether or not the extinguisher is fully charged. The inside is mostly filled with water, foam, or powder. As well, on the inside there is a cartridge containing carbon dioxide gas at high pressure. The cartridge is connected to a siphon tube which goes from the bottom of the extinguisher to a hose which is connected to the nozzle. When you squeeze the handle and the lever together, you compress a spring which opens a release valve at the top of the gas cartridge.
Fire extinguishers have seven parts.
Make a chart. On the left-hand side, name each part of a fire extinguisher. On the right-hand side, describe its role in how the fire extinguisher works. Some fire extinguishers have an extra part, a gauge which indicates the internal pressure of the extinguisher. From the description in the reading, draw a fire extinguisher.