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.