As shown in the illustrated LP centrifugal chiller high efficiency purge recovery unit piping schematic, what statement is true concerning the vacuum pump? Illustration GS-RA-55 Illustration GS-RA-55: the U.S. Coast Guard has not released this illustration.

Correct Answer: Option D — The vacuum pump is designed to remove refrigerant vapor from the carbon filter tank and transfer these vapors to the evaporator to minimize the loss of refrigerant to the atmosphere.

In low pressure centrifugal chiller purge units, the vacuum pump extracts desorbed refrigerant vapors from the carbon adsorption filter tank and routes them back into the main evaporator, preventing atmospheric venting and conserving refrigerant.