The document summarizes the components and operation of a fire extinguisher. It notes that fire extinguishers are usually made of special steel and painted red for easy identification. They contain water, a siphon tube, and a small gas cartridge inside the main container. The gas cartridge is connected to a valve and tube inside the container. Outside, a pin, lever, and nozzle make up the external system linked to the internal components. To use it, the pin is pulled and lever pushed down, releasing gas into the container and forcing water through the tube and out the nozzle to extinguish fires. Releasing the lever stops the gas release.

1. NGUYỄN TRẦN KHƯƠNG DUY
Writing p. 112
As far as I know, a fire extinguisher is a hermetic container which is usually made by
the special steel, so as to be safe and durable. Normally, the container is painted in red to
be recognized/to help people to recognize easily.
Under the ordinary condition, the container contains water, a siphon tube and a
cartridge of gas. Although the cartridge of gas is much smaller than the container but they
look like the same. The cartridge of gas also has a valve on the top which controls
releasing gas. The siphon tube and the cartridge of gas are fixed vertically along the
container and called the internal system.
The external system is made from three pieces of equiment including a pull pin, a
lever and a nozzle. Both systems are linked together perfectly and then kept securely at
the mouth of the container.
When people open the pin and then push down the lever, the rod opens valve
releasing gas into the main container. Following this, water is forced up the siphon tube
to release gas immediately throughout the nozzle. Conversely, if you do not want to
continue using, you should release the lever in order to stop gas.