We do not want to introduce water that may turn to steam and burn the occupants. So we try to use a combination of Positive pressure and interior attack to give the occupants the best chance of survival.
Why do they wait to put water on a fire?
Water puts out fire by creating a barrier between the fuel source and the oxygen source (it also has a cooling effect which has to do with the energy required to convert liquid water into water vapor). … Since grease floats on water, the water cannot block the fuel (grease) from the oxidizer (air).
Do you spray water at the fire?
Water does not extinguish Class B fires and can spread the flammable liquid, making it worse. You must only put out these fires with powder, foam, or carbon dioxide extinguishers to cut off the fire’s oxygen supply.
What do firefighters spray on water?
Firefighting foam is used instead of water for certain types of fires. There are two types of firefighting foam: Class A and Class B. Class A is used on ordinary combustibles to reduce the surface tension of the water, which better saturates the fuel, and Class B is used on flammable liquid fires.
Why is water spray more effective than a straight stream of water for fire suppression?
Many thousands of separate droplets injected into the hot fire gases will absorb more energy, more quickly than a straight stream that penetrates straight through with only the water on the outside of the stream exposed.
Do firefighters actually go into burning buildings?
Most fire departments have rules in place of when crews can enter burning buildings or not. But most of the time these rules become null in void when a possible victim is inside with a suspected survivable space.
What fire Cannot be put out by water?
APWs are designed for Class A (wood, paper, cloth) fires only. Never use water to extinguish flammable liquid fires. Water is extremely ineffective at extinguishing this type of fire, and you may, in fact, spread the fire if you try to use water on it. Never use water to extinguish an electrical fire.
Does salt put out fire?
Salt will smother the fire almost as well as covering it with a lid, while baking soda chemically extinguishes it. … Avoid using flour or baking powder, which can explode in the flames instead of snuffing them out.
Does water put out alcohol fire?
Common causes for these fires include gasoline, alcohol, and oil. … Water does not extinguish Class B fires and can spread the flammable liquid, making it worse. You must only put out these fires with powder, foam, or carbon dioxide extinguishers to cut off the fire’s oxygen supply.
Can fire trucks suck up water?
The large black pipes on the side of the engine are the hard suction lines. The primary function of any pumper/tanker fire engine is to carry water in a water tank or suck water in from an outside source, such as a fire hydrant, drop tank, swimming pool or lake. …
Do fire engines fill up in rivers?
Most structural (type 1 and 2) fire engines have tanks that can carry at least 500 gallons and frequently as much as 1,000 gallons of water.
Why do firefighters start fires?
Firefighters set backfires to stop the spread or change the direction of a wildfire. This is done by burning the fuel (grass, brush, trees, etc.) in front of a wildfire so it has nothing to burn when it reaches that point. Firefighters use a variety of tools to accomplish this.
Why do firefighters use a mist of water instead of a heavy stream?
It has the added benefit of shielding firefighters; the cloud of mist is very effective at absorbing radiated heat that can otherwise make it impossible to get close to a major fire.
What is the primary way that water extinguishes fire?
The primary way water extinguishes fire is by: absorbing heat. The energy required to raise the temperature of a substance by one degree is called: Specific Heat.
What does the E stand for in the acronym Slice RS?
C – Cool from a safe distance. E – Extinguish. R – Rescue. S – Salvage.