The semi-hermetic reciprocating compressor units can only be installed in refrigeration systems. After proper installation, they can be put into operation. They are widely used in cold storage, refrigerated transportation, frozen processing, display cabinets, and kitchen refrigerators, among other fields. They can accommodate a broader pressure range and refrigeration capacity requirements; they have high thermal efficiency with less electricity consumption per unit, especially the presence of gas valves makes it more apparent when operating away from the designed conditions; they have low material requirements, often using common steel materials, which are easier to process and more cost-effective; they are technically mature with extensive experience in production and use; the system is relatively simple.