Ch. 16 Fire Streams Flashcards
What is the minimum acceptable flow for interior structural fire attack?
150 gpm
What is the minimum acceptable hand line flow for operations in commercial occupancies?
250 gpm
Define critical flow rate
The flow at which the engine company can win the battle and kill the fire.
How many Btu’s does it take to raise 1 lb of water 1 degree Fahrenheit?
One
What temperature does water turn to steam?
212 degreed fahrenheit.
How many Btu’s does water absorb when it turns to steam?
970 Btu’s
This is called Latent Heat of Vaporization
What does Btu stand for?
British thermal units.
What is the formula for calculating how many Btu’s a given supply of water will absorb when applied to fire?
(Temperature of water - 212 degrees (the point at which water turns to steam)) + 970
This is how many Btu’s one pound of water will absorb. Then we must multiply this by 8.33 because 1 gallon of water weighs 8.33 lbs.
Then we must multiply this number by the number of gallons that are being put on the fire.
How much does water expand when it turns to steam?
1700 times it’s original volume
Nozzle reaction is measured in pounds of force and is a function of two factors. What are those factors?
Flow rate Nozzle pressure (NP)
What does increasing flow rate or nozzle pressure or increasing both do?
Increases Reaction Force (RF)
What is considered to be too much reaction force for a hand line?
More than 75 lbs of reaction force (RF).
What is considered a sign of an ineffective stream?
RF less than 45 lbs.
What are the factors of hose line handling characteristics?
Flow rate
Hose size
Friction loss
Pump discharge pressure
What three things do nozzles do?
Control flow, create shape, and provide reach.
