A thermostatic expansion valve (TEV) is a critical component in refrigeration and air conditioning systems. It regulates the flow of refrigerant into the evaporator. The TEV monitors the temperature at the evaporator's exit and reacts to the level of superheat. Superheat is defined as the difference between the refrigerant vapor's current temperature and its saturation temperature. Ensuring correct superheat levels is vital to prevent liquid refrigerant from entering the compressor, which could lead to damage. The TEV automatically modifies the flow to maintain the target superheat. Its sole sensing input is superheat, not load, ambient temperature, or pressure independently.