AS series 2-stage semi-hermetic refrigeration compressor is designed based on AR, AV, AW and AZ series compressors, and adopting 2-stage compressing technology and the interstage cooler. Its motor nominal power is 7.5HP-40HP, and the copressoring discharge pressure at I/II stage respectively are: 27/13.5、33/16.5、40/20、51/35、71/35.5、86/43、103/51.5、128/42.5、153/51 . The series has the characteristics of low load power, low discharge temperature, high efficient of cubage ect. , which greatly improves the compressors operating in the condition of low evaporating temperature. The series compressors use refrigerant 22, and they are capable of operating stably and chronically in the evaporating temperature of -50 centigrade . They may widly apply to air conditon, heat pump, and other industrial refrigerating system.