|モデル||究極の圧力||Pumping Speed (L/S)||Inlet Diam (mm)||Outlet Diam (mm)||Max.permissable Diff.pressure||Diff.pressure at overflow valve||エンジンパワー（kw）|
ZJP type pressure relief valve Roots vacuum pump uses a pair of 8-shaped rotors to make the same speed reverse rotation in the pump casing to generate suction and exhaust. Each rotor is supported by two bearings. The relative positions of the two rotors are always kept regular by a pair of synchronous gears. There is a gap between the rotor and the rotor, the rotor and the pump body, and the rotor and the side cover. No friction, no lubrication required. The support of the pump rotor adopts a reliable anti-backlash structure, the rotating parts are carefully balanced, and the high-precision helical gear is adopted. Therefore , the movement is stable, the noise is low, the use is more reliable, and the long-term surgery can be performed under the high pressure difference. The dynamic sealing part adopts the patented technology of the company and adopts the imported oil seal to control the runout of the shaft seal to be ≤ 0. 02mm, so the shaft seal does not leak oil. The self-weight valve is installed between the intake and exhaust ports of the pump, and its function is that the valve automatically opens when the pressure difference between the exhaust port and the intake port exceeds the valve’s own weight. This pressure difference is the maximum pressure difference at which the pump can operate reliably. Therefore , the Roots pump with relief valve has an programmed overload prevention function.
The ZJP Roots vacuum pump has a huge pumping rate at a lower inlet pressure and is equipped with an programmed anti-overload function. However , since the structure of the pump is a dry gap seal, in order to obtain a specific pumping rate and vacuum, and reduce the backflow, the pressure of the front stage must be reduced. Therefore , the front stage vacuum pump must be hooked up in series with the front stage vacuum pump. After pumping a specific degree of vacuum, restart the Roots vacuum pump, which is more economical. According to actual needs, different vacuum pumps works extremely well as the foreline pump, such as oil seal pump and liquid ring pump. It is worth mentioning that when a liquid ring pump can be utilised as the foreline pump, it is especially suited to occasions where a huge amount of condensable gas needs to be removed.