1. Suck air from sealed equipment or system to make absolute pressure lower than atmospheric pressure. It's better for wet or corrosive air. 2. Compact and easy connection with extruder 3. Clean filter net during running. 4. Reliable check function and excellent shockproof performance. Application 1. Vacuum dehydration, air removing and the material conveying. 2. Vacuum distillation and dryness in chemical industry 3. Vacuum distillation in drink industry.