Module 3

Question 1

the amount of water vapor suspended in the air at any time, compared with the amount of water vapor the air could hold if it were completely saturated

Answer 1

Relative humidity (RH)

Question 2

the temperature at which water vapor condenses as it is cooled

Answer 2

Dew point

Question 3

a device that causes air and water particles to separate

Answer 3

Moisture separator

Question 4

a device, usually installed between the aftercooler and the air receiver, that removes oil and moisture from the system

Answer 4

Oil scrubber

Question 5

Contaminants in air include dirt and _____.

Answer 5

Moisture

Question 6

What are the two types of preliminary filters used with compressors?

Answer 6

Wet, Dry

Question 7

Some dry filters use packed felt or cotton, and others use _____ elements.

Answer 7

Replaceable or Cartridge

Question 8

In a wet filter, dirt is collected in the oil and in the ______.

Answer 8

Filter

Question 9

The amount of water vapor contained in the air compared to what it could hold if it were completely saturated is called the _____.

Answer 9

Relative Humidity

Question 10

The temperature at which water vapor condenses as it is cooled is called its _____.

Answer 10

Dew Point

Question 11

The most common method used to remove vapor from compressed air is _____.

Answer 11

Condensation

Question 12

After coolers that are used to condense water vapor in compressed air are cooled by _____ or _____.

Answer 12

Water, air

Question 13

Water vapor in air begins to condense when the air is cooled to its _____.

Answer 13

Dew point

Question 14

Compressed air can be dried by reducing its _____.

Answer 14

Temperature

Question 15

Condensed moisture is usually removed from an aftercooler by a(n) _____ separator.

Answer 15

Mechanical

Question 16

Moisture that is not removed by a separator can be extracted by directing the air through a(n) _____.

Answer 16

Oil scrubber

Question 17

What are the two kinds of chemical air dryers used in pneumatic systems?

Answer 17

Deliquescent, adsorption

Question 18

The type of chemical that absorbs moisture in a deliquescent air dryer is called a(n) _____.

Answer 18

Desiccant

Question 19

The desiccant in an adsorption air dryer is regenerated by _____.

Answer 19

Heat

Question 20

The required size of the receiver in a compressed air system depends on the system’s requirements of _____, _____, and _____.

Answer 20

Air flow time, Air flow rate, Allowable pressure drop

Question 21

The most common contaminants in the air are dirt and _____.

Answer 21

Water vapor

Question 22

Which of the following is the most common method of removing vapor from compressed air?

a. Condensation
b. Evaporation
c. Freezing
d. Gravity separation

Answer 22

a. Condensation

Question 23

When washing a primary air filter, be sure to use _____.

Answer 23

A recommended solvent

Question 24

Which method of heat transfer is used in a shel-and-tube heat exchanger?

Answer 24

Counterflow

Question 25

What term is used to compare the amount of moisture in the air to what it could contain?

Answer 25

Relative humidity

Question 26

If all other factors are the same, the air that has the lowest dew point is the air that has the _____.

Answer 26

Least water vapor

Question 27

The amount of moisture that can be held in air decreases as the _____.

Answer 27

Pressure increases

Question 28

Most pneumatic systems remove moisture from the air stream by _____.

Answer 28

Mechanical separation

Question 29

What term best describes the condensation temperature of water vapor?

Answer 29

Dew point

Question 30

What type of air dryer uses a chemical agent that absorbs moisture from the air?

Answer 30

Deliquescent