ZJ series Roots Vacuum Pumps
The Roots vacuum pump's biggest advantage is having the higher suction capacity under the lower suction pressure. But it can't be used alone and must connect a fore pump together in series. While the pumped container's pressure that pumping by the fore pump firstly is close to the Roots pump's suction pressure, the Roots pump begins to work. In general, the high pressure difference is not permitted in Roots vacuum pump, or the pump will be damaged for over loading or over hot. So it is necessary to choose a suitable fore pump for Roots pump and connect the neseccary protected equipment.
The fore pumps are usually chosen the oil seal mechnical pump or liquid ring vacuum pump. Especially while pumping the gases that contains a great deal steam, the water ring vacuum pump is the ideal product being the fore pump.