USCG Exam PracticeRefrigeration and air conditioning
Liquid refrigerant returning to the compressor suction is called slugging or liquid floodback. What is the principal danger of this condition?
- A. It causes the suction pressure to rise above the high-pressure cutout setpoint
- ✓ It can break valves, connecting rods, or the crankcase because liquid cannot be compressedCorrect
- C. It washes lubricating oil out of the crankcase, causing immediate bearing failure
- D. It freezes at the suction valve, blocking refrigerant flow and starving the evaporator
Why B is correct
NAVEDTRA 14075 §6-2 states that liquid refrigerant cannot be compressed and can break valves, rods, or the crankcase — described as a serious casualty. While oil dilution is a related concern, the primary mechanical danger cited is the incompressibility of liquid causing physical damage to compressor components.
Cited:NAVEDTRA 14075 §6-2