🔍 Key Concepts

• In a vapor-compression refrigeration cycle, the highest refrigerant temperature occurs immediately after the refrigerant leaves the compressor discharge as high‑pressure superheated vapor. • Follow the flow direction arrows on the piping to see where discharge gas goes from compressor A toward the condenser B and any intermediate components (like vessel F). • Compare the roles of the valves in the suction line, liquid line from the condenser, and hot-gas discharge line to decide which one must see the hottest refrigerant.

💭 Think About

• Starting at compressor A, trace the refrigerant path in the direction of flow: which numbered valve is the first one that the discharge gas passes through before entering any condenser or cooling surface? • Look at each option (9, 16, 18, 20) and ask yourself: is this valve in a suction (low-temperature) line, a condensed liquid (cooled) line, or in the hot-gas discharge (hottest) line? • How would the refrigerant temperature change as it moves from the compressor discharge, through the condenser, then through the receiver/liquid line and finally back to the evaporators? Where along that path would the temperature peak?

✅ Before You Answer

• Verify which valve is located on the compressor discharge line (high pressure, superheated vapor) rather than on the suction or liquid lines. • Confirm the direction of flow arrows around valves 9, 16, 18, and 20 to see where in the cycle each valve sits. • Make sure the valve you choose is positioned upstream of the condenser B and downstream of compressor A, before any heat-rejection or cooling occurs.