In which applications is a TEV with an external equalizer used?

The use of a thermal expansion valve (TEV) with an external equalizer is particularly beneficial in applications where there is a high pressure drop across the evaporator. The external equalizer allows the TEV to better sense the actual pressure at the evaporator outlet, accounting for the pressure drop that occurs as the refrigerant flows through the system.

In systems with high pressure drops, the internal pressure at the bulb of the TEV may not accurately reflect the pressure at the outlet of the evaporator. By using an external equalizer, the TEV can make more precise adjustments to the flow of refrigerant entering the evaporator, which helps maintain optimal performance and efficiency. This is crucial for preventing issues such as flooding or starvation of the evaporator coil, ensuring reliable cooling and refrigeration performance.

In contrast, lower pressure drops or high-temperature applications may not require such sensitive adjustment, which is why an external equalizer might not be necessary in those situations. The choice of using an external equalizer is primarily based on the operating conditions and system design, reinforcing its specific purpose for high pressure drop scenarios.