Chapter 25

Question 1

Why should oxygen not be used to pressurize a system for leak checking purposes?
A. It could result in an explosion.
B. The oxygen can cause pitting of parts of the system.
C. An external source of moisture-free oxygen is required.
D. The oxygen combines with any non-condensable gases present to increase the system head pressure.

Answer 1

A

Question 2

After a refrigeration system is installed, a positive pressure test is performed using
A. propane,
B. methane,
C. nitrogen,
D. oxygen.

Answer 2

C

Question 3

What personal protective equipment is required when charging a system with a refrigerant?
A. Goggles
B. Face shield
C. Rubber gloves
D. Encapsulated suit

Answer 3

A

Question 4

What are some of the non-condensable gases that can be found in a refrigeration system?
A. Air
B. Impurities in the refrigerant
C. Gases caused by a lubrication breakdown
D. All of the above

Answer 4

D

Question 5

When it’s required to add oil to an operating refrigeration compressor and an oil pump is unavailable, what alternate method could be used to add oil?
A. Throttle the suction and feed oil to the crankcase.
B. Throttle the discharge and feed oil into the suction line.
C. Throttle the suction and feed oil into the suction line.
D. Throttle the discharge and feed oil into the crankcase.

Answer 5

A