ZJ/ZJP Series Roots Vacuum Pump

The greatest advantage of roots vacuum is high exhaust speed under low inlet pressure. However, the pump must be connected with a backing pump vacuum pump since the roots pump cannot work until the backing pump vacuumizes the pumped system to the allowed inlet pressure of the roots vacuum pump. Moreover, the roots vacuum pump cannot tolerate large pressure difference; Otherwise, the pump will be damaged by overload and overheat. Therefore, a suitable backing pump and safety devices are indispensable for the roots vacuum pump.
The backing pump can be vacuum pump like slide valve pump, rotary vane pump, water ring pump or oil ring pump. The water ring pump is quite ideal for gas with a great deal of perfect dynamic balance generated by discharge flange and suction flange which meet the international standards. High exhaust speed can be obtained in medium vacuum, thus running cost is lowered. The gap between rotators and between the pump body and rotators is strictly controlled to avoid frictions between moving parts in the pump cavity. All the flange parts are sealed by O rings instead of flat organic silicon rubber, making maintenance more convenient. Service life of the pump is greatly prolonged by well-chosen bearings and satisfactory lubrication. No lubricant exists in the pump cavity to ensure the dryness.