🔍 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
đź’ 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?
âś… 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.