Compressors can be divided into low-pressure compressors according to different exhaust pressures, and the exhaust pressure is less than1.0 MPa; ; Medium pressure compressor, the exhaust pressure is 65438±0.0 MPa ~ 65438±00 MPa;; High pressure compressor? Exhaust pressure10 MPa ~100 MPa; Ultra-high pressure compressor? The exhaust pressure is greater than 100MPa and so on. Low-pressure compressors are single-stage, and medium-pressure, high-pressure and ultra-high-pressure compressors are multi-stage, with the maximum number reaching 8 stages. At present, a polyethylene ultra-high pressure compressor with a pressure of 343MPa has been manufactured abroad. According to the different compression media, general compressors can also be called: air compressor, oxygen compressor, nitrogen compressor, hydrogen compressor, etc.