Comprehensive Study Guide & Practice Test
Q&A | 2025/2026 Latest Update | Fire Service
Promotion Prep
62.5 lbs - correct answerWhat does one cubic foot of water weigh?
1.728 cubic inches - correct answerWhat does One cubic foot of water contain in
inches?
7.5 gallons - correct answerWhat does One cubic foot of water contain in gallons?
8.35 lbs - correct answerWhat does One gallon of water weigh?
231 cubic inches - correct answerWhat does One gallon of water contain in inches?
.434 psi - correct answerWhat is One foot of water exert as a back pressure?
2.304 feet - correct answerHow high will One psi elevate water?
14.7 psi - correct answerWhat is atmospheric pressure at sea level?
34 feet - correct answerWhat is the maximum lift for drafting? (Theoretically)
1.13 feet of lift - correct answerHow high does One inch (1") mercury (inches in
vacuum) lift?
10 psi - correct answerWhat is the recommended minimum psi that should be
maintained on the compound gauge when taking water from a hydrant?
Stored or potential energy that is available to force water through pipes and fittings, fire
hose, and adapters. - correct answerWhat is Static pressure?
That part of the total pressure that is not used to overcome friction or gravity while
forcing water through fire hose, pipe, fittings, and adapters. - correct answerResidual
Pressure
Take Static pressure and subtracting residual pressure which gets you your drop. Take
your drop and multiply it by (2)² for second line, (3)² for third line, (4)² for forth line, (5)²
,for fifth line. so long as after you multiply drop and the multiplayer for the number line
and still have 10 psi left based off static pressure you can have that many lines if you
have less than 10 psi you can not operate that number of lines. - correct answerHow to
calculate psi loss for each additional line off hydrant and know how many lines can be
taken off hydrant?
Example: Static pressure: 65 psi Residual pressure : 60 psi
Drop: 5 psi
2nd line: 2²=4: 4x5= 20
3rd line: 3²=9: 9x5= 45
4th line: 4²=16: 16x5= 80 This line can't be done because it is over 65 psi - correct
answerExamples of how to calculate psi loss for each additional line off hydrant
1. 2 Hour: 100% @ 150 psi
2. 1/2 hour: 70% @ 200 psi
3. 1/2 hour: 50% @ 250 psi
4. 10 minutes: 100% @ 165 psi (overload or spurt test) - correct answerWhat are all the
steps in Certification Test (pre-service tests)?
100% @ 165 psi (done in certification test for 10 minutes) - correct answerWhat is a
Spurt or Overload test?
1. 20 minutes: 100% @ 150 psi
2. 10 minutes: 70 % @ 200 psi
3. 10 minutes: 50% @ 250 psi
Optional: 100% @ 165 psi (overload or spurt test) - correct answerWhat are all the
steps in a Service Test?
100% capacity @ 150 psi net pump pressure
70% capacity @ 200 psi net pump pressure
50% capacity @ 250 psi net pump pressure - correct answerWhat are Pump Tests?
Net Pump Pressure (NEP) is the measurement of the total work performed by the
pump:
a. To lift water into the pump (drafting)
b. To discharge water from the pump
NEP= Suction Side Work(drafting) + Discharge Side Work - correct answerWhat is Net
Engine/Pump Pressure (NEP)?
Examples:
Discharge gauge reads 165 psi but you are getting supplied by hydrant @ 65 psi on
your intake gauge. So the net pressure would only be 100 psi.
Now your are drafting and Intake gauge reads 20" mercury (-20) and Discharge reads
120 psi. So your net pump pressure is 140 - correct answerExamples of figuring out Net
Engine/Pump Pressure (NEP)
, Pump Discharge Pressure (PDP) is:
PDP= Net pump pressure(NEP) - Suction Side Work - correct answerWhat is Pump
Discharge Pressure?
Suction Side Work(psi)= Lift (ft)+Intake Hose FL(Friction Loss) (psi) Divided by 2.3 -
correct answerHow do you figure out Suction Side Work ?
100 psi - correct answerWhat is Fog nozzle pressure for Hand held nozzle and Master
Stream?
Hand Held : 50 psi
Master Stream: 80 psi - correct answerWhat is Smooth Bore nozzle pressures for Hand
held nozzle and Master Stream?
"For every action there is an equal and opposite reaction" - correct answerWhat is
Newton's Third Law of motion pertaining to Nozzle Reaction?
As water leaks a nozzle under pressure, it causes a reactionary force in the opposite
direction. - correct answerWhat is Nozzle Reaction?
The formula used for calculation of nozzle reaction is : NR= 1.57D²P - correct
answerWhat is the Nozzle Reaction formula?
For fog nozzles and master stream smooth bore tips, fire ground nozzle reaction
calculations can be computed at approximately 1/2 the flow (measured in lbs.). - correct
answerWhat is fire ground Nozzle Reaction calculations?
1. Air Resistance
2. Gravity - correct answerWhat are the two variables that affect the reach of fire
streams?
30-34 degrees - correct answerWhat angle does a stream get the greatest horizontal
reach?
60-75 degrees - correct answerWhat angle does a stream get the maximum effective
vertical reach?
10% to 15% - correct answerWhat percent can head and tail winds affect the reach of a
stream?
1"= 200 GPM
1-1/8"= 250 GPM
1-1/4"= 300 GPM
50 PSI FL for nozzle - correct answerWhat is Hand Lines Solid Stream GPM for tips?
1-1/4"= 400 GPM