Module 1

Question 1

A compressor that compresses air to only one end of a cylinder

Answer 1

Single-acting compressor

Question 2

Cooling air between compressor stages

Answer 2

Intercooling

Question 3

Cooling air after it leaves the compressor

Answer 3

Aftercooling

Question 4

Heat exchanger design where cooling water and air flow in opposite directions

Answer 4

Counterflow

Question 5

Heat exchanger design where cooling water and air flow in the same direction

Answer 5

Parallel flow

Question 6

relieving all internal pressure from the compressor

Answer 6

Unloading

Question 7

As a compressor increases the air pressure, it also reduces the air _____.

Answer 7

Volume

Question 8

What are the two classifications of air compressors when distinguished by their operating principles?

Answer 8

Positive displacement, Dynamic

Question 9

Name the two methods used to connect the compressor drive to the compressor.

Answer 9

Direct Driven, V-Belt Driven

Question 10

The movable part of a discharge valve is held in place by a(n) _____.

Answer 10

Spring

Question 11

A compressor that compresses air in more than one step is called a(n) _____ compressor.

Answer 11

Multistage

Question 12

Cooling the air between stages in a multistage compressor reduces the _____ requirements.

Answer 12

Horsepower

Question 13

Water-cooled intercoolers are usually _____ heat exchangers.

Answer 13

Shell-and-Tube

Question 14

The most efficient and commonly found flow arrangement in a water-cooled intercooler is _____.

Answer 14

Counterflow

Question 15

Cylinder-wall lubrication prevents piston rings from wearing, and _____.

Answer 15

Removes Heat

Question 16

The two basic methods used to lubricate a compressor are _____ lubrication and _____ lubrication.

Answer 16

Splash, Pressurized

Question 17

The lubrication method that is used for heavy-duty compressors is _____ lubrication.

Answer 17

Pressurized

Question 18

If oil-free air is required, compressors are used that require _____ lubrication or have only _____ lubrication.

Answer 18

No; Well-isolated bearing

Question 19

A large compressor is started only when the compressor is _____.

Answer 19

Unloaded

Question 20

Name at least two devices used to control pressure in a compressor.

Answer 20

Pressure Switch, Suction Unloader Valves, Centrifugal Pressure Release, Hydraulic unloader, Electric or Magnetic Unloader

Question 21

An alternate way of causing compressor output to vary is to change the _____ of the compressor.

Answer 21

Speed

Question 22

Name at least two advantages of reciprocating compressors.

Answer 22

Good Compression Ratios, Variety of Sizes, Low Operating Cost, and High Output in FT3/MIN/HP

Question 23

To be efficient, a positive displacement compressor must decrease the air’s _____.

Answer 23

Volume

Question 24

Dynamic compressors increase air pressure by _____.

Answer 24

Accelerating the air.

Question 25

The discharge valves of a compressor are opened by _____.

Answer 25

Compressed air.

Question 26

In which of the following ways are discharge valves closed? a. Electrical impulse b. Gravity c. Piston linkage d. Spring action

Answer 26

d. Spring action

Question 27

In multistage compressors, the required air pressure is created by compressing the air in _____.

Answer 27

Two or more unequal cylinders.

Question 28

Of what benefit is the use of an intercooler in a multistage compressor?

Answer 28

Decreases horsepower requirements.

Question 29

Air-cooled compressors are usually constructed with _____.

Answer 29

Cooling fins.

Question 30

Water or liquid intercoolers are usually patterned after which of the following? a. Automotive radiator b. Evaporative coolers c. Finned radiators d. Shell-and-tube heat exchangers

Answer 30

D. Shell-and tube heat exchangers.

Question 31

What lubrication method is used for heavy-duty compressors?

Answer 31

Pressurized

Question 32

When a compressor is relieved of all internal pressure, it is said to be _____.

Answer 32

Unloaded.