Freezing and refrigeration system debugging and precautions I. Precautions during operation of the refrigeration system: The expansion valve is one of the four major components of the refrigeration system. It is an important device for regulating and controlling the flow and pressure of the refrigerant into the evaporator. It is also the \"demarcation line\" on the high and low pressure side. Its adjustment is not only related to the normal operation of the entire refrigeration system, but also an important indicator of the operator's skill level. The adjustment of the expansion valve must be performed carefully and patiently. The adjustment of the pressure must take place through the evaporator and the temperature of the warehouse to produce boiling (evaporation), and then enter the compressor suction chamber through the pipeline to reflect on the pressure gauge, which requires a time process.