DPO Exam Questions and Answers Latest Version 2025 Already Passed
Completed product after air is introduced and it leaves the nozzle - Answers What is finished mechanical
foam?
185 psi - Answers PDP should not exceed ________ psi unless the standpipe system had been designed
to withstand higher pressures
1,700 times its original volume. - Answers At 212°F approximately how much does water expand?
Centrifugal pump - Answers What type of fire pump must be primed using an external priming device?
British thermal unit; The amount of heat required to raise the temperature of 1 pound of water 1°F -
Answers What is a BTU?
0mph - Answers Once the power take off (PTO) had been properly achieved and the pump is engaged,
the vehicle spedometer should show a speed of?
More surface area of the water is exposed to absorb heat - Answers What is the main advantage of
using a fog nozzle over a solid stream nozzle during fire attack?
grid or loop - Answers A ______ hydrant distribution system is a network of water mains which provides
circulating feed
14.7psi - Answers What is atmospheric pressure at sea level?
Entrapping water instead of air - Answers Fire gels work by?
Suddenly stopping water moving through a hose or pipe that results in an energy surge - Answers What
is Water hammer
Primary feeder - Answers Hydrant w/ the largest capacity will be one that is connected to a?
Looped line or circulating feed hydrants receive water from two directions, dead-end hydrants receive
water from only one direwction - Answers Why are looped line/circulating hydrants generally considred
better than dead-end hydrants?
350gpm - Answers What is the maximum amount of water that can safely flow from a handline nozzle?
80psi - Answers What is the nozzle pressure for a master stream operating a solid stream?
Stretch a medium size diameter supply line into the building and connect it to the standpipe hose outlet
on the first floor - Answers If a FDC is found inoperable, the way to bypass it so operations can be
performed is?
Placing one pumper at a hydrant and a second pumper connected intake to intake --- water flows from
intake to intake without going through the first pump's impeller - Answers what is a Dual-pumping
operation?
, fog stream nozzle - Answers A constant flow nozzle is what type of nozzle?
Friction loss - Answers Water flowing through hoses and appliances results in what type of pressure
loss?
Automatic fog - Answers What is the most common variable flow fog nozzle used today?
decreased capacity - Answers Water temperature greater than 90 degrees F can cause _______ in the
fire pump
dry-barrel - Answers In a ________ hydrant, a small drain valve opens as the hydrant is closed
Aircraft cargo - Answers A piercing nozzle would be used on?
100psi - Answers What is the nozzle pressure for a master stream fog nozzle?
Late arriving pumpers to hook up without interrupting relay operations - Answers In-line relay valves
allow for?
150psi - Answers When performing a capacity test, the desired net pump pressure should be ________
psi
dry standpipe system - Answers A _______ depends solely on an external water source to provide water
to firefighters during a highrise fire
Flush the pump w/ clean water - Answers What should be done after drafting contaminated water
through the pump?
More than half of the rated capacity of the pump will be required - Answers You should switch from
pressure to volume when?
Cellar, chimney, water curtain - Answers What are some examples of special purpose nozzles?
Greater reach of firestream, lighter hose lines, small uniform bubbles that are very durable - Answers
Compressed air foam system results in?
Any fire stream that is too large to be controlled without mechanical aid - Answers What is a master
stream
Foam solution flow requirements, available water pressure, type of foam - Answers Selection of a
proportioner depends on?
The pressure of a liquid on the bottom of a vessel is independent of the shape of the vessel - Answers
What is the 6th principle of pressure?
1000 gallons - Answers According to NFPA 1901, to be considered a mobile water supply apparattus the
apparatus must carry at least how many gallons of water?
Completed product after air is introduced and it leaves the nozzle - Answers What is finished mechanical
foam?
185 psi - Answers PDP should not exceed ________ psi unless the standpipe system had been designed
to withstand higher pressures
1,700 times its original volume. - Answers At 212°F approximately how much does water expand?
Centrifugal pump - Answers What type of fire pump must be primed using an external priming device?
British thermal unit; The amount of heat required to raise the temperature of 1 pound of water 1°F -
Answers What is a BTU?
0mph - Answers Once the power take off (PTO) had been properly achieved and the pump is engaged,
the vehicle spedometer should show a speed of?
More surface area of the water is exposed to absorb heat - Answers What is the main advantage of
using a fog nozzle over a solid stream nozzle during fire attack?
grid or loop - Answers A ______ hydrant distribution system is a network of water mains which provides
circulating feed
14.7psi - Answers What is atmospheric pressure at sea level?
Entrapping water instead of air - Answers Fire gels work by?
Suddenly stopping water moving through a hose or pipe that results in an energy surge - Answers What
is Water hammer
Primary feeder - Answers Hydrant w/ the largest capacity will be one that is connected to a?
Looped line or circulating feed hydrants receive water from two directions, dead-end hydrants receive
water from only one direwction - Answers Why are looped line/circulating hydrants generally considred
better than dead-end hydrants?
350gpm - Answers What is the maximum amount of water that can safely flow from a handline nozzle?
80psi - Answers What is the nozzle pressure for a master stream operating a solid stream?
Stretch a medium size diameter supply line into the building and connect it to the standpipe hose outlet
on the first floor - Answers If a FDC is found inoperable, the way to bypass it so operations can be
performed is?
Placing one pumper at a hydrant and a second pumper connected intake to intake --- water flows from
intake to intake without going through the first pump's impeller - Answers what is a Dual-pumping
operation?
, fog stream nozzle - Answers A constant flow nozzle is what type of nozzle?
Friction loss - Answers Water flowing through hoses and appliances results in what type of pressure
loss?
Automatic fog - Answers What is the most common variable flow fog nozzle used today?
decreased capacity - Answers Water temperature greater than 90 degrees F can cause _______ in the
fire pump
dry-barrel - Answers In a ________ hydrant, a small drain valve opens as the hydrant is closed
Aircraft cargo - Answers A piercing nozzle would be used on?
100psi - Answers What is the nozzle pressure for a master stream fog nozzle?
Late arriving pumpers to hook up without interrupting relay operations - Answers In-line relay valves
allow for?
150psi - Answers When performing a capacity test, the desired net pump pressure should be ________
psi
dry standpipe system - Answers A _______ depends solely on an external water source to provide water
to firefighters during a highrise fire
Flush the pump w/ clean water - Answers What should be done after drafting contaminated water
through the pump?
More than half of the rated capacity of the pump will be required - Answers You should switch from
pressure to volume when?
Cellar, chimney, water curtain - Answers What are some examples of special purpose nozzles?
Greater reach of firestream, lighter hose lines, small uniform bubbles that are very durable - Answers
Compressed air foam system results in?
Any fire stream that is too large to be controlled without mechanical aid - Answers What is a master
stream
Foam solution flow requirements, available water pressure, type of foam - Answers Selection of a
proportioner depends on?
The pressure of a liquid on the bottom of a vessel is independent of the shape of the vessel - Answers
What is the 6th principle of pressure?
1000 gallons - Answers According to NFPA 1901, to be considered a mobile water supply apparattus the
apparatus must carry at least how many gallons of water?
