🔍 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.