ESCO Air Conditioning Practice Exam 2025 – Complete Study Resource

The thermostatic expansion valve is a vital component in an air conditioning system that regulates the flow of refrigerant entering the evaporator coil. The three operating pressures associated with the thermostatic expansion valve are compressor pressure, spring pressure, and sensor bulb pressure.

- Compressor pressure: This pressure is the high side or discharge pressure of the refrigerant leaving the compressor.

- Spring pressure: The spring inside the expansion valve helps control the opening and closing of the valve to regulate the flow of refrigerant.

- Sensor bulb pressure: The sensor bulb is filled with a special fluid that expands and contracts based on the temperature of the refrigerant leaving the evaporator coil. This pressure is crucial for the valve to adjust the refrigerant flow rate based on the system's cooling demands.

Understanding these three pressures allows the thermostatic expansion valve to operate efficiently and maintain optimal performance in the air conditioning system.

The other options are incorrect because they do not accurately represent the operating pressures associated with the thermostatic expansion valve.