Question 9Refrigeration & AC - 1st Asst/Chief

The correct answer is D) head pressure regulating valve. The valve shown in the illustration is used to regulate the head pressure in the refrigeration system. The head pressure is the pressure on the high-pressure side of the refrigeration cycle, which is maintained by the compressor. The head pressure regulating valve helps to control this pressure to ensure efficient operation of the system. The other answer choices are incorrect because: A) A thermostatic expansion valve is used to control the flow of refrigerant into the evaporator, not the head pressure. B) A suction pressure regulating valve is used to control the pressure on the low-pressure side of the system, not the head pressure. C) An evaporator pressure regulating valve is also used to control the low-pressure side, not the high-pressure side.