Oklahoma Service Technician Practice Exam

The primary function of an expansion valve in refrigeration systems is to regulate the flow of refrigerant into the evaporator coil. This component plays a critical role in controlling the amount of refrigerant that enters the evaporator, ensuring optimal cooling efficiency. When the refrigerant passes through the expansion valve, it experiences a pressure drop, which allows it to expand and drop in temperature before entering the evaporator coil. This cooling effect is essential for absorbing heat from the surrounding environment, thereby facilitating the refrigeration cycle.

By adjusting the flow based on the cooling demands of the system, the expansion valve contributes to maintaining the desired temperature and operational efficiency of the refrigeration system. Proper regulation ensures that the evaporator coil has the right amount of refrigerant to absorb heat effectively, preventing issues such as underfeeding or overfeeding, which could impair the system's cooling performance.