Zhejiang L&B developed self-priming pumps, used in food processing, pharmaceutical and chemical industry. It is specifically designed for pumping materials which contain air or gas, and it can also be used for negative inhalation with pre-aspiration filtration equipment. It can be used for alcohol, oil, syrup, volatile matter, such as alcohol, acetone and other solvents, or other temperature near the boiling point materials. However, the primary purpose of this pump is for the recovery of CIP. The impeller is located between the inlet (between pump body and the venturi sleeve), which is fitted with the pump shaft for rotation. The rotation of the impeller and the arrangement of the side grooves create a negative pressure in the inlet pump, resulting in suction of the pump. At the same time, the fluid receives energy in the form of kinetic energy and pressure energy, thereby driving it through the impeller cover. Such as in the sucking room, the milk sucked out from the milk bucket, or in the automatic CIP cleaning system, as the cleaning cylinder back pump, mechanical seal for the built-in flow, drawing material temperature is not higher than 100 ℃.