Compressor PHEP

Question 1

If all other factors are held constant, the volume of a dry gas decreases…

Answer 1

In direct proportion to an increase in pressure

Question 2

Absolute pressure is equal to :

Answer 2

Gauge pressure plus 14.7

Question 3

If 500 cubic inches of gas under a pressure of 15 psia is compressed to 20 cubic inches, what will the new pressure be?

Answer 3

375 psia,
Formula P1/P2 = V1/V2

Question 4

The quantity and pressure of air discharged from a centrifugal fan depends on the:

Answer 4

ALL OF THE ABOVE:
- size of the fan rotor
- speed of the fan rotor
- density of the air

Question 5

Increasing the speed of an unbalanced shaft will:

Answer 5

Move the center of gravity further from the axis of rotation thereby increasing the unbalance

Question 6

Which of the following conditions would not normally contribute to a reciprocating air compressor explosion?

Answer 6

Excessive compressed air demands

Question 7

Large reciprocating air compressors are generally unloaded while starting and stopping to:

Answer 7

Reduce the starting torque and permit more gradual stopping

Question 8

The temperature at which molecules of water vapor begin to condense upon the surface of objects as air is cooled is called the:

Answer 8

Dew Point

Question 9

High outlet compressed air temperatures could be caused by all of the following EXCEPT:

Answer 9

Low oil level

Question 10

Air receivers are installed on all reciprocating air compressors to:

Answer 10

ALL OF THE ABOVE:
- dampen pressure waves
- reduce pressure drops
- remove moisture or sludge