Question 184Refrigeration & AC - Assistant Engineer

The correct answer is A) thermal expansion valve. The thermal expansion valve is the device responsible for maintaining constant superheat at the evaporator coil outlet of a refrigeration system. It does this by automatically adjusting the flow of refrigerant into the evaporator coil based on the temperature and pressure conditions, ensuring that the refrigerant is completely evaporated before it enters the compressor. The other options are incorrect because: B) the king valve is used to isolate the refrigerant system, C) the low-pressure cutout switch is a safety device that shuts off the compressor if the suction pressure drops too low, and D) the solenoid valve is used to control the flow of refrigerant, but does not specifically maintain superheat.