FDNY A35 Exam Questions and Answers
(Updated Verified Answers)
• Air compressors are used to? -✓✓Power industrial equipment and construction tools.
• Air Compressors enable? -✓✓The efficient repair of all types of vehicles and facilitate
their safe operation.
• Air compressors are important in? -✓✓Manufacturing and are central to product
development and creation.
• A FDNY permit is required if a compressor is? -✓✓Used to compress any
nonflammable, corrosive or oxidizing gas, including air to a pressure exceeding 100 psi.
(Outdoor air compressing does not require a permit unless it is a fair or festival)
• What does an air compressor do? -✓✓It takes the air in a room and forces it into a
container under pressure.
• Compressed air is used to power? -✓✓Pneumatic wrenches and lifts in automobile
service stations. Heavy machinery and paint spray booths in industrial plants.
• What are the different types of air compressors? -✓✓Reciprocating, centrifugal, rotary
and scroll compressors.
• What is the difference between air compressor types? -✓✓How they compress air.
• What is the most used air compressor? -✓✓Reciprocating.
• What are air compressors sometimes called? -✓✓Air pumps.
• How can air compressors be powered? -✓✓Electric motors, internal combustion
engines, and steam turbines.
• What is the most common power source for an air compressor? -✓✓An Electric motor.
• Flammable gases and air compressors. -✓✓In places like service stations or
workshops there may be a build up of flammable gases, which are heavier than air and
fall to the floor before spreading outward. These gases are easily ignited by sparks and
high temperatures including the heat generated by an air compressor.
• How high must an air compressor be and why? -✓✓- Must be at least 5 feet above the
ground.
, - A raised air compressor is less likely to ignite flammable gases.
• How do air compressors work? -✓✓They take the air from a room where it is
compressed in the compression chamber, when the air reaches a certain pressure it is
moved to the air receiver (air tank). The more air forced into the container, the greater
the pressure. Compressed air can be discharged from the container at a controlled rate.
• How is the air compressor powered? -✓✓The air compressor is powered by an electric
motor (or one of the other power sources) which activates a series of drive belts that
power the moving parts of the unit. (The belts are similar to the ones that drive power
steering and alternator)
• What is the compression chamber? -✓✓The compression chamber is a piston inside a
cylinder which compresses the air.
• How does the compression chamber work? -✓✓The piston moves downward and
draws air into the cylinder through the intake valve, which automatically opens when it
moves down. When the piston reaches the bottom of the cylinder it moves upward
compressing the air and automatically closing the intake valve so no air escapes.
• How does the Air Receiver work? -✓✓After the upward stroke of the piston
compresses the air to a certain level of pressure it forces open a discharge valve, which
releases the compressed air into the Air Receiver.
• Is the discharged valve spring loaded? -✓✓Yes
• 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
(Updated Verified Answers)
• Air compressors are used to? -✓✓Power industrial equipment and construction tools.
• Air Compressors enable? -✓✓The efficient repair of all types of vehicles and facilitate
their safe operation.
• Air compressors are important in? -✓✓Manufacturing and are central to product
development and creation.
• A FDNY permit is required if a compressor is? -✓✓Used to compress any
nonflammable, corrosive or oxidizing gas, including air to a pressure exceeding 100 psi.
(Outdoor air compressing does not require a permit unless it is a fair or festival)
• What does an air compressor do? -✓✓It takes the air in a room and forces it into a
container under pressure.
• Compressed air is used to power? -✓✓Pneumatic wrenches and lifts in automobile
service stations. Heavy machinery and paint spray booths in industrial plants.
• What are the different types of air compressors? -✓✓Reciprocating, centrifugal, rotary
and scroll compressors.
• What is the difference between air compressor types? -✓✓How they compress air.
• What is the most used air compressor? -✓✓Reciprocating.
• What are air compressors sometimes called? -✓✓Air pumps.
• How can air compressors be powered? -✓✓Electric motors, internal combustion
engines, and steam turbines.
• What is the most common power source for an air compressor? -✓✓An Electric motor.
• Flammable gases and air compressors. -✓✓In places like service stations or
workshops there may be a build up of flammable gases, which are heavier than air and
fall to the floor before spreading outward. These gases are easily ignited by sparks and
high temperatures including the heat generated by an air compressor.
• How high must an air compressor be and why? -✓✓- Must be at least 5 feet above the
ground.
, - A raised air compressor is less likely to ignite flammable gases.
• How do air compressors work? -✓✓They take the air from a room where it is
compressed in the compression chamber, when the air reaches a certain pressure it is
moved to the air receiver (air tank). The more air forced into the container, the greater
the pressure. Compressed air can be discharged from the container at a controlled rate.
• How is the air compressor powered? -✓✓The air compressor is powered by an electric
motor (or one of the other power sources) which activates a series of drive belts that
power the moving parts of the unit. (The belts are similar to the ones that drive power
steering and alternator)
• What is the compression chamber? -✓✓The compression chamber is a piston inside a
cylinder which compresses the air.
• How does the compression chamber work? -✓✓The piston moves downward and
draws air into the cylinder through the intake valve, which automatically opens when it
moves down. When the piston reaches the bottom of the cylinder it moves upward
compressing the air and automatically closing the intake valve so no air escapes.
• How does the Air Receiver work? -✓✓After the upward stroke of the piston
compresses the air to a certain level of pressure it forces open a discharge valve, which
releases the compressed air into the Air Receiver.
• Is the discharged valve spring loaded? -✓✓Yes
• 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
