Why is water a good extinguisher

Another factor affecting the density of the water is the level of impurities in the water. Again for simplicity, it can be assumed that water is incompressible due to the insignificant changes in density under a large change in pressure. Another important relative measurement is specific gravity Sg. The specific gravity is defined as the ratio of the density of the substance to the density of another.

In this case, pressure and temperature must be taken into effect. Particularly with gases, the weight density changes significantly with pressure and temperature. Values of the specific gravities of some common substances are shown in the table bellow. Water freezes and boils at 0 o C and o C respectively at standard pressure and temperature, that is at sea level and atmospheric pressure.

The boiling and freezing points are affected by pressure as expected. But when water boils, it expands to times its previous size as mentioned earlier. This is important as the expansion of water as it freezes causes undrained automatic fire sprinkler piping in improperly heated buildings to break, and underground piping not buried deep enough to rupture. Water as an fire extinguishing agent Hydraulic calculation for fire protection engineers.

Finally, we said earlier that if you get enough heat then the water molecule can break down into hydrogen and oxygen and while this is unlikely to happen within the confines of your home or office — metal fires involving metals such as Potassium, Sodium, Magnesium, etc.

This makes for a very explosive combination, indeed, as the hydrogen gas produced will ignite violently in the presence of oxygen. Check out what happens when water is put on a flammable metal in this case magnesium :. Use a class D fire extinguisher, like this one, instead. While ordinary fires of solid material are often easily extinguished with water, electrical fires, oil or liquid fires, and metal fires should never be tackled with water.

You are at a high risk of harming yourself, property, and others if you do so. Does it Work? Does Cost Money? The Price of Emergency Calls. Can It Start a Fire? Skip to content As an Amazon Associate, I earn from qualifying purchases at no added cost to you. Is Fire Alive? Conclusion Related Articles:. How does water put out fire?

What will happen if you put water on an electrical fire? Don't use water to put out a grease fire! Firefighter shows what happens. This has been used as a concern for not using fog nozzles to generate steam. To avoid any possible injury from steam generation at structure fires, the following three prerequisites are essential:. Above all, training fires need to be extinguished before attempting a real-world fire attack on a structure that could produce volumes of steam.

When all of this is in place, structural fire suppression effectiveness will significantly improve and the actual use of water to extinguish fires will be reduced for the communities that employ effective fire suppression which reduces water consumption records. The above numbers clearly indicate the inefficiency of applying water by straight stream method, although this method may be necessary for coping with deepseated fires and for overhauling fires.

Water that is not used effectively in fire extinguishment often results in more water damage to the property than the fire itself. Two fast-growing developments in structural fire suppression may have a significant impact on water demand needs for specific occupies and for initial fire attack in the near future. First, is the use of water mist technology for special-hazard fire problems and for protecting one- and twofamily homes. Second, is both the introduction of Class A Foams and the technology to apply these foams for the reported dramatic improvement of confining and extinguishing developing structure fires to the room or area of origin.

Each of these approaches to improved structural fire suppression is examined separately. Skip to main content. Search for:. To avoid any possible injury from steam generation at structure fires, the following three prerequisites are essential: 1 Fire suppression personnel needs to be trained to stay close to the ground or floor level where the attack is initiated since the steam will rise to the highest point of the enclosure.