Questions and CORRECT Answers
Above 212 degrees F water converts to? - CORRECT ANSWER - Gas, water vapor, steam.
What is water measured in? - CORRECT ANSWER - Pounds per cubic foot.
What does water weigh for fire protection purposes? - CORRECT ANSWER - 62.4 lb/ft3 or
8.3 lb/gal
How does water extinguish fire? - CORRECT ANSWER - Cooling or absorbing heat or
smothering.
Water can smother fires in combustible liquids with a specific gravity? - CORRECT
ANSWER - Higher than 1 (heavier than water)
What are the advantages of water? - CORRECT ANSWER - -Water absorbs heat better.
-It takes large amounts of heat to convert water to steam.
-greater surface area the more heat absorbed.
- at 212 degrees F water converts to steam 1700 times its volume.
- water is inexpensive and readily available.
What are the disadvantages of water? - CORRECT ANSWER - -Higher surface tension
-Water may react with fuels, combustible metals, sodium metal and tritely aluminum
-radiant heat can pass thru water
-below 32 degrees F water freezes
- water conducts electricity
- water is heavy
,What is pressure? - CORRECT ANSWER - Force per unit area exerted by a liquid or gas in
PSI or kilopascal (kPa)
What is force? - CORRECT ANSWER - Simple measure of weight in pounds
A column of water 2.304' high... - CORRECT ANSWER - exerts 1 psi at base
How many principles determine action or pressure on fluids? - CORRECT ANSWER -6
principles
What principle states that the fluid pressure is perpendicular to any surface? - CORRECT
ANSWER - 1st principle
What principle states that the fluid pressure at a point in fluid at rest is the same in all directions?
- CORRECT ANSWER - 2nd principle
What principle states that pressure in a confined fluid is transmitted in all directions? -
CORRECT ANSWER - 3rd principle
What principle states that the pressure of a liquid in an open vessel is proportional to its depth? -
CORRECT ANSWER - 4th principle
What principle states that the pressure of a liquid in an open vessel is proportional to the density
if the liquid? - CORRECT ANSWER - 5th principle
How much more dense is mercury than water? - CORRECT ANSWER - 13.55
What principe states that the pressure of a liquid at the bottom of a vessel is independent of the
shape of the vessel? - CORRECT ANSWER - 6th principle
,What is atmospheric pressure at sea level? - CORRECT ANSWER - 14.7 psi
How tall is mercury with a pressure of 1 psi? - CORRECT ANSWER - 2.04"
What is pressure less than atmospheric pressure? - CORRECT ANSWER - vacuum
What is absolute zero? - CORRECT ANSWER - perfect vacuum
What is the height of water supply above the discharge opening? - CORRECT ANSWER -
Head pressure
For every 1' increase in elevation, how many psi are gained? - CORRECT ANSWER - .434
psi
What is pressure stored as energy available to force water through pipes, fitting, hoses and
adapters? - CORRECT ANSWER - static pressure
What is pressure in a system before water flows from a hydrant? - CORRECT ANSWER -
static pressure
What is pressure in a system during normal consumption? - CORRECT ANSWER - normal
operating pressure
What is the difference between static pressure and normal pressure cause by flowing water? -
CORRECT ANSWER - friction
What is the portion of pressure not used for friction loss? - CORRECT ANSWER - Residual
pressure
, What is water flowing from a discharge forward velocity? - CORRECT ANSWER - Flow
pressure
What must you use in order to measure flow pressure? - CORRECT ANSWER - Smooth bore
and a pitot tube.
What is the height of a point above sea level or some other reference point? - CORRECT
ANSWER - Elevation
What is the geographic position of a location or object in relation to sea level? - CORRECT
ANSWER - Altitude
What is the gain or loss of pressure in a hose line due to a change in the elevation? - CORRECT
ANSWER - elevation pressure
What happens to atmospheric pressure as the height above sea level increases? - CORRECT
ANSWER - Atmospheric pressure drops
Above sea level, atmospheric pressure decreases __________ for every __________ feet -
CORRECT ANSWER - .5 psi, 1000'
What is loss of pressure by water moving through a pipe? - CORRECT ANSWER - friction
loss
What causes friction loss in fire hose? - CORRECT ANSWER - -movement of water
molecules
-the lining of fire hose/ delaminating hose
-couplings
-sharp bends/ kinks
-change in his size or orifice by adapters