Which of the following correctly describes the role of an expansion valve?

The role of an expansion valve is to reduce the pressure of the refrigerant as it moves from the high-pressure side of the system to the low-pressure side. This component functions by allowing the refrigerant to expand and cool, which is essential for the refrigeration cycle. When the refrigerant passes through the expansion valve, its pressure drops significantly, leading to a drop in temperature. This process prepares the refrigerant to absorb heat efficiently in the evaporator, thereby facilitating the cooling process in the system.

In contrast, increasing the pressure of the refrigerant would lead to inefficiencies in the system and disrupt the flow. Circulating refrigerant is the role of the compressor and various other components rather than the expansion valve itself. Absorbing heat from the environment is primarily the function of the evaporator, where low-pressure refrigerant absorbs heat to cool the surrounding air. Thus, reducing the pressure of the refrigerant is the correct function attributed to the expansion valve within the refrigeration cycle.