Applications & Features： 1.Low noise. 2.ZJP Overflow valve for preventing thermal overloading. 3.High pumping speed in the wide pressure rang. 4.Gas protection device for evacuating high-boiling working media. 5.Checking is convenient. 6.Insensitive to the dust and water vapour contained. 7.Low drive power. 8.They find wide application in the fields of metallurg, chemical, textile and electronics industries.