The validity period of fire extinguishers is 5 to 10 years.
Water-based fire extinguishers are common water fire extinguishers and are generally suitable for extinguishing fires involving combustible materials such as wood and paper. Water fire extinguishers cool and extinguish fires by spraying water. Water-based fire extinguishers are generally valid for 5 years and need to be replaced after expiration. In addition, it is also very important to regularly check the pressure of the water fire extinguisher to ensure that it is operating properly.
Dry powder fire extinguishers are the most common type of fire extinguishers and are often used to extinguish fires involving combustible materials such as wood, paper, and grease. It inhibits the growth of fire by releasing dry powder to form a chemical reaction. Dry powder fire extinguishers are generally valid for 6 years and need to be replaced after expiration.
CO2 fire extinguishers are mainly used to extinguish fire sources such as electrical equipment and engines that are not easily in contact with water. CO2 fire extinguishers extinguish fires by releasing carbon dioxide, which can quickly reduce the oxygen concentration in the space to extinguish the source of the fire. CO2 fire extinguishers are generally valid for 10 years, but they also need to be visually inspected and pressure tested every year to ensure they are working properly.
The origin of fire extinguishers
In ancient times, fire extinguishing equipment was very simple, nothing more than hooks, axes, shovels, buckets and the like. The first truly dedicated fire extinguisher was invented by Manby, a British captain and Norfolk native, in 1816. It was just one or two barrels filled with more than 1 liter of water and filled with compressed air.
By the mid-19th century, French doctor Gallier invented the portable chemical fire extinguisher. Mix sodium bicarbonate and water in the barrel, and use a glass bottle to hold sulfuric acid in the mouth of the barrel. When used, the striker breaks the bottle, mixing the chemical substances, producing carbon dioxide, and forcing the water out of the barrel.
In 1905, Professor Laurent of Russia invented a foam fire extinguishing agent in St. Petersburg. He mixed aluminum sulfate and sodium bicarbonate solution and added a stabilizer. After spraying, a foam containing carbon dioxide was generated, which floated on the fire. Burning oil, paint or gasoline can effectively isolate oxygen and suffocate the flame.
In 1909, Davidson of New York obtained a patent for using carbon dioxide to press out carbon tetrachloride from a fire extinguisher. The liquid would immediately turn into a non-flammable heavier gas to suffocate the flame. Since then, dry powder fire extinguishers, liquid carbon dioxide fire extinguishers and other small fire extinguishers have appeared.