Question 59Refrigeration & AC - QMED

The correct answer is B) internal needle valve orifices of various sizes to accommodate different heat removal capacities. Thermostatic expansion valves are used to control the flow of refrigerant into the evaporator based on the superheat of the refrigerant. Rather than having a different valve body size for each capacity, manufacturers use a few standard valve body sizes and incorporate different sized internal needle valve orifices. This allows them to accommodate a range of heat removal capacities without the need for an infinite variety of valve body sizes. The other options, such as adjustable superheat, flexible diaphragms, or internal equalizers, are not the primary method used by manufacturers to handle different capacities.