What purpose does the equalizer line serve on a TXV?

The equalizer line on a thermal expansion valve (TXV) plays a crucial role in the system's functionality by conveying evaporator outlet pressure to the valve diaphragm. This connection is essential since it allows the TXV to sense the pressure of the refrigerant as it exits the evaporator coil.

By providing the outlet pressure information to the diaphragm, the equalizer line helps the TXV modulate the flow of refrigerant into the evaporator based on the actual load conditions. This ensures that the TXV can adjust to varying demands on the system, ultimately maintaining optimal performance and efficiency.

When the evaporator experiences changes in pressure — such as during varying cooling loads — the equalizer line helps the TXV respond appropriately by balancing the pressures on both sides of the diaphragm. This interaction allows for precise control of the refrigerant flow, thus enhancing the overall efficiency and effectiveness of the air conditioning system.