🔍 Key Concepts
• Follow the refrigerant flow from the condenser/receiver toward the common and freeze box evaporators
• Identify where refrigerant is definitely all liquid and subcooled (downstream of the condenser/receiver but upstream of any expansion device or solenoid that causes a pressure drop
• Use the symbols in GS‑RA‑12 to distinguish between condenser (B), receiver/liquid line, and expansion valves/solenoids near components G, H, J, and K
💭 Think About
• On the common/freezer circuit, at what point does the refrigerant first experience a major pressure-reducing device (such as a TXV or solenoid)? Everything just before that point should be high‑pressure liquid.
• Compare the piping between B and each numbered valve in the answer choices. For which pair does the entire segment stay on the high‑pressure liquid line without passing through any throttling or evaporating component?
• Look for the section of line that is shared by both the common and freeze box circuits. Between which components in the choices is that shared liquid line located?
✅ Before You Answer
• Confirm which lettered component is the condenser outlet/high‑pressure liquid source (look closely at B and downstream piping).
• Identify which numbered items 23, 29, and 37 are expansion or solenoid valves located just ahead of the evaporators; subcooled liquid will be found before these devices, not after them.
• Trace the line that serves both the common and freeze box evaporators; verify that, between your chosen pair, the refrigerant remains in the high‑pressure liquid line and does not pass through any evaporator, receiver, or pressure‑reducing device.