At one time or another, every technician has run into a refrigeration system that is not functioning properly. The question then becomes how to diagnose and determine if the problem is the thermostatic expansion valve — also known as the TXV.
Understanding the purpose of the TXV makes the diagnostic process easier. While the compressor is the heart of the system, causing the refrigerant to circulate, the TXV allows the system to work by creating the pressure difference between the high- and low-pressure sides of the refrigeration system.