The rupture disc on a low pressure centrifugal refrigeration unit is used as an over pressure protection device and is set to relieve at 15 psig and is most likely to lift when the compressor is idle? Where is the rupture disc located?

Correct Answer: Option D — on top of chiller evaporator shell

Low-pressure centrifugal chillers use R-123 or similar refrigerants operating under a vacuum at ambient standstills. A rupture disc is installed on top of the evaporator shell to relieve pressure safely to the atmosphere if ambient warming causes excessive over-pressurization while idle.