As shown in the illustrated LP centrifugal chiller pressure maintenance system, what is its functional purpose? GS-RA-40 Illustration GS-RA-40: the U.S. Coast Guard has not released this illustration.

Correct Answer: Option D — prevent the entrance of air into the chiller when the chiller is idle

Low-pressure centrifugal chillers operate below atmospheric pressure when idle; the pressure maintenance system prevents ambient air and moisture from leaking into the refrigerant side, protecting against contamination and purge unit overload.