🔍 Key Concepts

• Behavior of refrigerant when it is restricted at the expansion valve • Normal location and pattern of frosting in a properly operating refrigeration system • How pressure and temperature change upstream vs downstream of a restriction

💭 Think About

• If the expansion valve is obstructed, what happens to refrigerant flow into the evaporator and its ability to absorb heat? • Where would you expect the largest pressure drop and temperature change to occur when there is a restriction at the valve? • Which symptom would most directly indicate that liquid refrigerant is not reaching the evaporator correctly?

✅ Before You Answer

• Compare where frosting normally appears in a healthy system versus where it would shift if the restriction is right at the valve • Think about whether a blocked valve would more likely raise or lower downstream pressure and how that affects frosting • Eliminate any option that describes a symptom that would result from too much flow rather than restricted flow