Type 3

Question 1

Low pressure systems operate in _______.

Answer 1

Vacuum below atmosphere pressure

Question 2

Leaks and gaskets or fittings will cause what to enter into the system?

Answer 2

Air and moisture

Question 3

Low pressure chiller Purge Units

Answer 3

Purge units removed, noncondensibles that leak into low pressure chiller systems

Question 4

Excessive running of the purge system generally indicates what?

Answer 4

Leaking system

Question 5

What is the maximum test pressure or a low pressure centrifugal chiller with nitrogen?

Answer 5

10 psig. Exceeding could cause the rupture just to fail.

Question 6

What is the high-pressure cut out control typically set for on a recovery unit used for evacuating/recovering the refrigerant from a low pressure chiller?

Answer 6

10 psig

Question 7

After all the liquid has been removed, an average 350 ton R123 chiller at 0 psig would still have approximately _______ pounds of refrigerant in the vapor state?

Answer 7

100 pounds

Question 8

When removing refrigerant oil, it should be heated to _______ degrees as less refrigerant will be contained in the oil at higher temperature 

Answer 8

130 degrees F

Question 9

What will help make refrigerant recovery go faster in chiller type equipment?

Answer 9

Systems, water pumps, recovery, compressor and recovery condenser water should all be on during vapor or liquid removal from a low pressure refrigeration system. Raising room temperature will also result in faster recovery 

Question 10

Before disposing of a low pressure appliance, the refrigerant must be recovered or evacuated to ______mm of Hg absolute?

Answer 10

25 mm of HG