FDNY A35 CORRECT FINAL EXAMS QUESTIONS
AND ANSWERS SURE A+
✔✔What is a single stage air compressor? - ✔✔A compressor with one cylinder and
one piston or multiple pistons and cylinders that discharge directly into the air receiver.
✔✔What is a multi-stage air compressor? - ✔✔A compressor with multiple pistons and
cylinders that take air discharged from the previous cylinder and increase the pressure
to a new level, this continues until it reaches the last cylinder where it is then discharged
into the air receiver.
✔✔When air is compressed it becomes? - ✔✔Heated.
✔✔What is an intercooler? - ✔✔A device installed on multistage compressors, between
the stages of an air compressor to cool the air as it travels between compression
stages.
✔✔Storage containers - ✔✔In some systems the compressed air from the receiver is
forced into storage containers allowing it to be used later as needed.
✔✔How do systems of several connected air compressors work? - ✔✔The air is draw
into the first compressor and then forced into the second which forces it into the next
compressor, this continues until the air passes through all the connected compressors.
Finally the air is forced into the hose line or storage container.
Each time the air passes through a compressor the pressure increases, this system is
used when very high pressure air is needed.
✔✔What is an Unloading Valve? - ✔✔A safety component that allows air to escape the
compression chamber when there is strain on the electric motor.
(The strain usually occurs when the motor is first started. Automatic in most systems
may be manual in older systems)
, ✔✔What is a Check Valve? - ✔✔A safety device that prevents the back flow of air from
the tank to the compressor head.
Must be installed between the air compressor head air line and the unloading valve air
line, or the air will escape as soon as the compressor stops and the unloading valve
opened.
✔✔What is a Pressure Gauge? - ✔✔A device that indicates the pressure inside the air
receiver, if the pressure exceeds the recommended maximum it may explode.
✔✔What is a pressure switch? - ✔✔A switch that controls the pressure.
✔✔What are pressure relief valves? - ✔✔These valves allow air to escape from the
system when the pressure is too great. The valves operate automatically and can be
operated manually by pulling on the ring attached to the pressure relief valves.
✔✔Why does the Air intake valve have a filter? - ✔✔To prevent dust from entering the
compression cylinder, if dust enters the compressor the heat inside can cause the dust
to catch fire.
✔✔What is the Filter and Moisture Separator Assembly (FMSA)? - ✔✔A device used to
take moisture out of compressed air, it is installed between the air compressor and the
air receiver. A drain cock is attached to the FMSA to drain the water and dust before it
enters the receiver.
Moisture can cause problems when using compressed air to power machinery.
✔✔What is the Automatic Control Device? - ✔✔A device attached to the air receiver
which controls the starting and stopping of the air compressor. It shuts the compressor
down when the air pressure in the receiver is sufficient, it restarts the compressor if
more pressure is needed.
✔✔What are Safety Relief Valves? - ✔✔A device used to keep the air compressor tank
from bursting should the pressure switch stop working.
✔✔What is a Constant Speed Control Switch? - ✔✔A device sometimes installed on a
system when there is a steady demand for compressed air, it allows the compressor the
run continuously at a safe speed while supplying the desired amount of air. If demand
drops the excess air is allowed to escape into the atmosphere through the pressure
release valve.
✔✔Cooling Systems. - ✔✔Cooling systems are installed in each unit. The compression
chamber and compressed air must be cooled to prevent the compressor from
overheating and causing serious damage.
AND ANSWERS SURE A+
✔✔What is a single stage air compressor? - ✔✔A compressor with one cylinder and
one piston or multiple pistons and cylinders that discharge directly into the air receiver.
✔✔What is a multi-stage air compressor? - ✔✔A compressor with multiple pistons and
cylinders that take air discharged from the previous cylinder and increase the pressure
to a new level, this continues until it reaches the last cylinder where it is then discharged
into the air receiver.
✔✔When air is compressed it becomes? - ✔✔Heated.
✔✔What is an intercooler? - ✔✔A device installed on multistage compressors, between
the stages of an air compressor to cool the air as it travels between compression
stages.
✔✔Storage containers - ✔✔In some systems the compressed air from the receiver is
forced into storage containers allowing it to be used later as needed.
✔✔How do systems of several connected air compressors work? - ✔✔The air is draw
into the first compressor and then forced into the second which forces it into the next
compressor, this continues until the air passes through all the connected compressors.
Finally the air is forced into the hose line or storage container.
Each time the air passes through a compressor the pressure increases, this system is
used when very high pressure air is needed.
✔✔What is an Unloading Valve? - ✔✔A safety component that allows air to escape the
compression chamber when there is strain on the electric motor.
(The strain usually occurs when the motor is first started. Automatic in most systems
may be manual in older systems)
, ✔✔What is a Check Valve? - ✔✔A safety device that prevents the back flow of air from
the tank to the compressor head.
Must be installed between the air compressor head air line and the unloading valve air
line, or the air will escape as soon as the compressor stops and the unloading valve
opened.
✔✔What is a Pressure Gauge? - ✔✔A device that indicates the pressure inside the air
receiver, if the pressure exceeds the recommended maximum it may explode.
✔✔What is a pressure switch? - ✔✔A switch that controls the pressure.
✔✔What are pressure relief valves? - ✔✔These valves allow air to escape from the
system when the pressure is too great. The valves operate automatically and can be
operated manually by pulling on the ring attached to the pressure relief valves.
✔✔Why does the Air intake valve have a filter? - ✔✔To prevent dust from entering the
compression cylinder, if dust enters the compressor the heat inside can cause the dust
to catch fire.
✔✔What is the Filter and Moisture Separator Assembly (FMSA)? - ✔✔A device used to
take moisture out of compressed air, it is installed between the air compressor and the
air receiver. A drain cock is attached to the FMSA to drain the water and dust before it
enters the receiver.
Moisture can cause problems when using compressed air to power machinery.
✔✔What is the Automatic Control Device? - ✔✔A device attached to the air receiver
which controls the starting and stopping of the air compressor. It shuts the compressor
down when the air pressure in the receiver is sufficient, it restarts the compressor if
more pressure is needed.
✔✔What are Safety Relief Valves? - ✔✔A device used to keep the air compressor tank
from bursting should the pressure switch stop working.
✔✔What is a Constant Speed Control Switch? - ✔✔A device sometimes installed on a
system when there is a steady demand for compressed air, it allows the compressor the
run continuously at a safe speed while supplying the desired amount of air. If demand
drops the excess air is allowed to escape into the atmosphere through the pressure
release valve.
✔✔Cooling Systems. - ✔✔Cooling systems are installed in each unit. The compression
chamber and compressed air must be cooled to prevent the compressor from
overheating and causing serious damage.
