Operating Principle and Capabilities: The series SYF roots vacuum pump is with overflow valve. The figure-of-eight rotors are counter-rotating at a frequent speed within the pump housing for suction and exhaust of gas. Two rotors are supported by two bearings and synchronized by a gear, which guarantees these two rotors in certain relative positions. They may be close to to one another and to the housing with out real contacting, so lubrication is pointless in the functioning housing. The thoroughly balanced operating elements and high precision bevel wheels ensue the pump be operated stably and constantly beneath the ailment of high-pressure variation. Dynamic seal part makes use of our patent technology and imported oil seals, the vibration volume of shaft on the shaft seals is managed to significantly less than 0.02mm. A gravity valve is installed among the suction and exhaust part of the pump. The perform with the gravity valve is as follows, once the strain variation among the suction and exhaust component is more than the weight on the valve, the valve opens automatically, which helps make the strain big difference constantly keep within a fixed controllable value, the worth could be the allowable highest stress variation to guarantee the pump operate ordinarily and so that in truth, 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 substantially increased speed at comparatively reduced inlet stress and it can be possessed overload self-protective function. Since it is a pump of dry clearance seal development, if a specific pumping pace fee 15 and an greatest vacuum have to be obtained, it can be essential to supply a reduce inlet stress for lowering the back movement, consequently, a pump should be backed in use, roots vacuum pump needs to be commenced quickly after its inlet stress reaches a permissible worth for economization. It’s allow to select various varieties of pump as the backing pump for factual requirements, this kind of as oil seal pump and liquid ring vacuum pump. When pumping the gas containing substantial level of vapor, the liquid ring vacuum pump could be the best backing pump.