Which of the following is not a main type of automatic refrigeration flow control?

The condenser equalizer valve is not categorized as a main type of automatic refrigeration flow control. In refrigeration systems, the main types of automatic flow control mechanisms are designed to manage the flow of refrigerant within the system to optimize efficiency and maintain desired temperatures.

Thermostatic expansion valves and electronic expansion valves play crucial roles in adjusting the flow of refrigerant based on temperature changes and requirements. The thermostatic expansion valve operates by using a diaphragm that responds to the temperature of the refrigerant leaving the evaporator, thus optimizing the refrigerant flow to maintain proper superheat levels. On the other hand, the electronic expansion valve employs electronic controls to precisely regulate the refrigerant flow based on real-time conditions within the system.

Flow control valves, while potentially useful in various applications, are typically manual and not automatic in nature, setting them apart from the main automatic types focused on dynamic control.

In contrast, the condenser equalizer valve primarily serves to balance pressure in the condenser, which is a different function from controlling the flow of refrigerant through the system. Its role does not involve regulating or adjusting refrigerant flow in the way that the other listed components do, thereby confirming that it is not a main type of automatic refrigeration flow control.