Question 133Refrigeration & AC - 1st Asst/Chief

The correct answer is C. The expansion valve designed to maintain a constant evaporator pressure rather than a constant evaporator superheat is the thermostatic expansion valve (TXV), which is represented by option C in the illustration. The TXV is designed to maintain a constant pressure in the evaporator by automatically adjusting the refrigerant flow based on changes in the evaporator load, which helps to optimize the system's performance. The other options, A, B, and D, represent different types of expansion valves that are designed to maintain a constant evaporator superheat rather than a constant evaporator pressure.