Working Principle and Functions: The series SYF roots vacuum pump is with overflow valve. The figure-of-eight rotors are counter-rotating at a continual pace within the pump housing for suction and exhaust of gasoline. Two rotors are supported by two bearings and synchronized by a gear, which ensures these two rotors in particular relative positions. They may be close to to one another and to the housing without having real contacting, so lubrication is pointless inside the doing work housing. The cautiously balanced operating elements and higher precision bevel wheels ensue the pump be operated stably and continuously underneath the problem of high-pressure big difference. Dynamic seal portion makes use of our patent technologies and imported oil seals, the vibration level of shaft on the shaft seals is controlled to much less than 0.02mm. A gravity valve is put in between the suction and exhaust a part of the pump. The perform on the gravity valve is as follows, when the stress variation among the suction and exhaust portion is more than the fat on the valve, the valve opens instantly, which helps make the strain variation normally keep inside a fixed controllable worth, the worth is definitely the allowable highest pressure big difference to make certain the pump do the job normally and in order that in truth, the roots vacuum pump with overflow valve is a type of overload self-protective pump. Series SYF roots vacuum pump with overflow valve has substantially larger pace at reasonably reduced inlet strain and it really is possessed overload self-protective perform. As it is usually a pump of dry clearance seal building, if a particular pumping velocity charge 15 and an greatest vacuum must be obtained, it is actually required to supply a lower inlet strain for lowering the back movement, thus, a pump have to be backed in use, roots vacuum pump really should be started quickly immediately after its inlet stress reaches a permissible value for economization. It is actually permit to select distinctive sorts of pump since the backing pump for factual needs, this kind of as oil seal pump and liquid ring vacuum pump. When pumping the fuel containing substantial level of vapor, the liquid ring vacuum pump would be the suitable backing pump.