Generalize：In the market, big capacity high pressure compressors are provided by multi-stage big piston type or multiple small piston units installed in parallel which use single-acting cylinder with high internal leakage rate,low efficiency and high energy consumption.As we all know,big piston compressor unit means higher investment cost, and associated installation and maintenance costsas well.On the other hand,numerous number of wearing and consumable parts for multiple small piston units setup leads to high failure rate and in turn causes much production down time.