🔍 Key Concepts

• Non-condensable gases in refrigeration systems and why they must be removed • Where air and other non‑condensables naturally collect in a low‑pressure system • The normal flow path of refrigerant: compressor → condenser → expansion device → evaporator → back to compressor

💭 Think About

• In a low‑pressure system, think about which component is at the highest pressure and temperature, and where non‑condensable gases are most likely to separate from the liquid refrigerant. • A purge‑recovery unit is designed to remove mainly air and other gases, not liquid refrigerant; which component would have a space where these gases can accumulate above the liquid? • Look at each option and ask: in this component, is there a likely "gas pocket" at the top where non‑condensables would gather and from which they can be drawn off safely?

✅ Before You Answer

• Verify which component normally contains a mixture of liquid refrigerant and non‑condensable gases with a vapor space at the top. • Check which component’s top portion is specifically designed or commonly used as a connection point for purge lines in low‑pressure systems. • Eliminate components that are normally full of liquid or are primarily suction/discharge gas flow paths without a quiet space for non‑condensables to collect.