Operating Principle and Functions: The series SYF roots vacuum pump is with overflow valve. The figure-of-eight rotors are counter-rotating at a consistent pace within the pump housing for suction and exhaust of gasoline. Two rotors are supported by two bearings and synchronized by a gear, which assures these two rotors in selected relative positions. These are close to to one another and also to the housing devoid of real contacting, so lubrication is needless inside the operating housing. The thoroughly balanced working components and large precision bevel wheels ensue the pump be operated stably and continuously under the ailment of high-pressure big difference. Dynamic seal element utilizes our patent technologies and imported oil seals, the vibration level of shaft around the shaft seals is controlled to much less than 0.02mm. A gravity valve is put in among the suction and exhaust part of the pump. The perform in the gravity valve is as follows, once the stress variation among the suction and exhaust aspect is in excess of the bodyweight in the valve, the valve opens instantly, which helps make the stress big difference normally hold within a fixed controllable value, the value could be the allowable highest strain difference to be sure the pump work commonly and so that the truth is, the roots vacuum pump with overflow valve is often a sort of overload self-protective pump. Series SYF roots vacuum pump with overflow valve has considerably greater velocity at somewhat lower inlet strain and it is possessed overload self-protective function. Because it is really a pump of dry clearance seal building, if a particular pumping speed rate 15 and an ultimate vacuum must be obtained, it really is important to supply a decrease inlet strain for decreasing the back flow, consequently, a pump needs to be backed in use, roots vacuum pump really should be started off quickly just after its inlet stress reaches a permissible value for economization. It truly is permit to pick distinct types of pump since the backing pump for factual prerequisites, this kind of as oil seal pump and liquid ring vacuum pump. When pumping the gas containing substantial quantity of vapor, the liquid ring vacuum pump is the suitable backing pump.