DPO PRACTICE EXAM QUESTIONS AND
ANSWERS 100% PASS 2026/2027
The main feature of a relief valve is to - ANS relieve excessive pressure within the pump
Theoretically, the max distance a pump can lift water at sea level is - ANS 33.8 feet
Available flow from hydrants is estimated by determining the perfect drop between the static
and _____ pressures. - ANS Residual
High-energy foam systems introduce: - ANS compressed air into the foam solution prior to
discharge into the hoseline.
In-line relay valves allow for: - ANS late-arriving pumpers to hook up without interrupting
operations
A____distribution system is a network of water mains. - ANS Grid
A factor to be considered when determining the rate of application for fire fighting foam is: -
ANS the type of foam concentrate used
2026/2027 ALLRIGHTS RESERVED
1
, When a centrifugal pump loses prime at a draft, check for: - ANS a clogged strainer
For business and industrial districts, water mains should be at least ___ inches. - ANS 8
Inches
A hydrant with the largest capacity will be one that is connected to a: - ANS primary feeder
What is the friction loss in 300 feet of 2-1/2" rubber lined hose flowing 350 gpm? - ANS 74
psi
What is the desired pump pressure when supplying two lines of 2-1/2 inch hose, one 200 feet
long and one 300 feet long each with a 250 gpm nozzle operating at 100 psi? - ANS 137.5 psi
Switch from pressure to volume operation when: - ANS it is expected that more than half of
the rated capacity of the pump will be required
Nozzle reaction is explained by the law of physics that states: - ANS for every action there is
an equal and opposite reaction.
The test that ensures the piping between the water tank and pump is sufficient to supply the
minimum amount of water specified by NFPA 1901 is the: - ANS tank-to-pump flow test
The actual max height to which water will be lifted when the intake gauge reads 9 inches of
mercury is ____ - ANS 10.17 feet
What is the flow from a 2 inch nozzle with ideal nozzle pressure? - ANS 1063 gpm
2026/2027 ALLRIGHTS RESERVED
2
ANSWERS 100% PASS 2026/2027
The main feature of a relief valve is to - ANS relieve excessive pressure within the pump
Theoretically, the max distance a pump can lift water at sea level is - ANS 33.8 feet
Available flow from hydrants is estimated by determining the perfect drop between the static
and _____ pressures. - ANS Residual
High-energy foam systems introduce: - ANS compressed air into the foam solution prior to
discharge into the hoseline.
In-line relay valves allow for: - ANS late-arriving pumpers to hook up without interrupting
operations
A____distribution system is a network of water mains. - ANS Grid
A factor to be considered when determining the rate of application for fire fighting foam is: -
ANS the type of foam concentrate used
2026/2027 ALLRIGHTS RESERVED
1
, When a centrifugal pump loses prime at a draft, check for: - ANS a clogged strainer
For business and industrial districts, water mains should be at least ___ inches. - ANS 8
Inches
A hydrant with the largest capacity will be one that is connected to a: - ANS primary feeder
What is the friction loss in 300 feet of 2-1/2" rubber lined hose flowing 350 gpm? - ANS 74
psi
What is the desired pump pressure when supplying two lines of 2-1/2 inch hose, one 200 feet
long and one 300 feet long each with a 250 gpm nozzle operating at 100 psi? - ANS 137.5 psi
Switch from pressure to volume operation when: - ANS it is expected that more than half of
the rated capacity of the pump will be required
Nozzle reaction is explained by the law of physics that states: - ANS for every action there is
an equal and opposite reaction.
The test that ensures the piping between the water tank and pump is sufficient to supply the
minimum amount of water specified by NFPA 1901 is the: - ANS tank-to-pump flow test
The actual max height to which water will be lifted when the intake gauge reads 9 inches of
mercury is ____ - ANS 10.17 feet
What is the flow from a 2 inch nozzle with ideal nozzle pressure? - ANS 1063 gpm
2026/2027 ALLRIGHTS RESERVED
2
