FDNY A35 EXAM QUESTIONS AND ANSWERS 100%
CORRECT
Air compressors power... - (1) industrial equipment and (2) construction tools
Examples of equipment powered by air compressor - pneumatic wrenches, lifts in auto
service stations, paint spray booths
Air compressors enable... - (1) efficient repair of all types of vehicles; and (2) facilitate
their safe operation on public thoroughfares
Permit is required for air compressor - that compresses air above 100 PSI
Types of air compressors - (1) reciprocating;
(2) centrifugal;
(3) solar; and
(4) rotary
*Difference is the way in which they compress air
How do air compressors work - take the air in a room and force it into a container
UNDER PRESSURE. The more air forced into the container, the greater the pressure.
Compressed air can be discharged from the container at a controlled rate.
Most common air compressor - Reciprocating
Air compressors are sometimes called - air pumps
Air compressors can be powered by: - (1) electric motors;
(2) internal combustion engines; or
(3) steam turbines
Explosions & air compressors - If there is a build up of flammable gases (ex: in service
stations and workshops), those gases are heavier than air and fall to the floor before
spreading outward. These gases are easily ignited by sparks and high temperatures--
which INCLUDES the heat generated by an air compressor.
To avoid explosions w/ air compressors - Raise air compressor at LEAST 5 feet above
ground level so that no flammable gases are drawn into the compressor. To meet the
height requirement you can place compressor on a shelf or bench OR the air receiver
tank may be turned and stood on end w/ the air compressor bolted to the top of the
tank.
, Power to air compressor - entire unit is driven by an electric motor. Motor activates a
series of drive belts. Belts power the moving parts of the unit--like w/ power steering and
alternator in automobile
Compression Chamber operation - Air is compressed in compression chamber which
consists of a PISTON inside a CYLINDER. Piston moves up and down.
When piston moves down -->draws air into cylinder, through INTAKE VALVE (valve
automatically opens when piston moves down).
When piston moves up-->air is compressed (intake vale automatically closes to avoid
air escaping from cylinder).
Air Reciever Operation - When air pressure reaches a certain level, it forces open a
DISCHARGE VALVE (which is spring loaded). This releases compressed air into air
reciever (aka air tank), which is what supplies compressed air when needed.
Single Stage Air Compressor - with one cylinder and one piston
Multi Stage Air Compressor - with more than one piston and cylinder.
Each cylinder will increase the pressure of the air by taking air from the discharge side
of the previous cylinder and increasing the pressure to a new level. Once it reaches the
last level, the pressurized air is discharged into the reciever.
As air is compressed it becomes - heated.
This is why in a multi stage air compressor there is an intercooler between stages of
compressor.
Exception to single stage/multi stage distinction - CAVEAT: there are air compressors
with multiple pistons and cylinders that are single stage but these are only the ones
where each cylinder discharges directly into air receiver (unlike a true multi stage air
compressor).
Storage containers - some systems force the compressed air from the receiver into
storage containers allowing it to be used later as needed.
System of Connected Air Compressors - Air forced from one compressor into another
several time to increase pressure each time and ultimately forced into a hose line or
storage container.
Used when there is a need for air under very high pressure.
Unloading Valve - safety component.
CORRECT
Air compressors power... - (1) industrial equipment and (2) construction tools
Examples of equipment powered by air compressor - pneumatic wrenches, lifts in auto
service stations, paint spray booths
Air compressors enable... - (1) efficient repair of all types of vehicles; and (2) facilitate
their safe operation on public thoroughfares
Permit is required for air compressor - that compresses air above 100 PSI
Types of air compressors - (1) reciprocating;
(2) centrifugal;
(3) solar; and
(4) rotary
*Difference is the way in which they compress air
How do air compressors work - take the air in a room and force it into a container
UNDER PRESSURE. The more air forced into the container, the greater the pressure.
Compressed air can be discharged from the container at a controlled rate.
Most common air compressor - Reciprocating
Air compressors are sometimes called - air pumps
Air compressors can be powered by: - (1) electric motors;
(2) internal combustion engines; or
(3) steam turbines
Explosions & air compressors - If there is a build up of flammable gases (ex: in service
stations and workshops), those gases are heavier than air and fall to the floor before
spreading outward. These gases are easily ignited by sparks and high temperatures--
which INCLUDES the heat generated by an air compressor.
To avoid explosions w/ air compressors - Raise air compressor at LEAST 5 feet above
ground level so that no flammable gases are drawn into the compressor. To meet the
height requirement you can place compressor on a shelf or bench OR the air receiver
tank may be turned and stood on end w/ the air compressor bolted to the top of the
tank.
, Power to air compressor - entire unit is driven by an electric motor. Motor activates a
series of drive belts. Belts power the moving parts of the unit--like w/ power steering and
alternator in automobile
Compression Chamber operation - Air is compressed in compression chamber which
consists of a PISTON inside a CYLINDER. Piston moves up and down.
When piston moves down -->draws air into cylinder, through INTAKE VALVE (valve
automatically opens when piston moves down).
When piston moves up-->air is compressed (intake vale automatically closes to avoid
air escaping from cylinder).
Air Reciever Operation - When air pressure reaches a certain level, it forces open a
DISCHARGE VALVE (which is spring loaded). This releases compressed air into air
reciever (aka air tank), which is what supplies compressed air when needed.
Single Stage Air Compressor - with one cylinder and one piston
Multi Stage Air Compressor - with more than one piston and cylinder.
Each cylinder will increase the pressure of the air by taking air from the discharge side
of the previous cylinder and increasing the pressure to a new level. Once it reaches the
last level, the pressurized air is discharged into the reciever.
As air is compressed it becomes - heated.
This is why in a multi stage air compressor there is an intercooler between stages of
compressor.
Exception to single stage/multi stage distinction - CAVEAT: there are air compressors
with multiple pistons and cylinders that are single stage but these are only the ones
where each cylinder discharges directly into air receiver (unlike a true multi stage air
compressor).
Storage containers - some systems force the compressed air from the receiver into
storage containers allowing it to be used later as needed.
System of Connected Air Compressors - Air forced from one compressor into another
several time to increase pressure each time and ultimately forced into a hose line or
storage container.
Used when there is a need for air under very high pressure.
Unloading Valve - safety component.
