USCG Exam PracticeRefrigeration cycle and components
A reciprocating refrigeration compressor receives liquid refrigerant at its suction inlet instead of dry vapor. Which of the following casualties is the most likely result?
- A. The condenser tubes will scale rapidly due to elevated discharge temperature
- B. The filter-drier will become saturated and restrict refrigerant flow
- C. The high-pressure cutout will trip due to elevated head pressure
- ✓ Valves, connecting rods, or the crankcase may be damaged because liquid cannot be compressedCorrect
Why D is correct
Liquid refrigerant entering the compressor suction — called slugging or liquid floodback — cannot be compressed and can break suction or discharge valves, connecting rods, or the crankcase. This is a serious mechanical casualty. The other options describe real system faults but are not the direct result of liquid entering the compressor.
Cited:NAVEDTRA 14075 §6-2