What is the primary purpose of a refrigeration expansion valve?

The primary purpose of a refrigeration expansion valve is to regulate refrigerant flow into the evaporator. This component plays a crucial role in the refrigeration cycle by controlling the amount of refrigerant that enters the evaporator, which is essential for efficient heat absorption. When the refrigerant flows into the evaporator, it absorbs heat, causing the refrigerant to change from a liquid to a gas. By adjusting the flow, the expansion valve ensures that the evaporator operates effectively and maintains the desired temperature. This regulation helps prevent issues such as flooding (too much refrigerant) or starvation (too little refrigerant) within the evaporator, both of which can lead to inefficient cooling and potential damage to the system.

The other options do not accurately reflect the function of the expansion valve. Increasing refrigerant pressure is typically associated with the compressor, while decreasing temperature is a result of the evaporator process itself, not a direct function of the expansion valve. Condensing refrigerant gas into liquid primarily occurs in the condenser, not through the expansion valve. Therefore, the correct answer highlights the key role of the expansion valve in optimizing refrigerant flow and ensuring the efficiency of the refrigeration system.