🔍 Key Concepts

• Contamination risks in a sealed refrigeration system • Effects of introducing air or non-condensable gases into the system • Safe methods for purging hoses and tools before connecting to the system

💭 Think About

• Which substance, if left in the pump and hoses, would be most harmful to system performance: air, nitrogen, or clean refrigeration oil? • What is the primary goal when preparing the hand pump and hoses before connecting to the refrigeration system? • Think about which choice describes a normal service procedure versus something that would be unusual or risky for the compressor crankcase.

✅ Before You Answer

• Confirm which medium is acceptable to be inside the refrigeration circuit (is dry nitrogen normally left in the system during operation?) • Check which options involve purging the pump and hoses versus purging the compressor crankcase • Verify that the chosen method avoids introducing non‑condensable gases into the system