Single-stage pump is mainly composed of the pump body, pump cover, motor and other components, installed in the single-stage pump body pump shaft, bearing, impeller, mechanical seal and mechanical seal gland, characterized in that , Which also includes a pair of couplings located between the motor output shaft and the pump shaft and a guide bearing mounted on the housing to assist in supporting the pump shaft; a multistage pump is a simple series connection of many single-stage pumps, combine it all toghther. His output pressure can be large. Is a centrifugal pump, but also rely on the rotation of the impeller to obtain centrifugal force, thus the material. Until the density of the gas reaches the working range of the mechanical vacuum pump and is withdrawn to gradually obtain a high vacuum. Multi-stage pump is based on changes in the volume of the pump to achieve suction, compression and exhaust, so it is a variable volume centrifugal pump. The difference between single-stage pump and multi-stage pump Because multi-stage pump is a sublimation version of a single stage pump, there are many similarities between the two. However, in practice, the difference exists between the two. The difference between the two is as follows: 1, single-stage pump is only one impeller pump, the highest lift is only 125 meters; 2, multi-stage pump refers to the pump with two or more impellers, the maximum lift can be more than 125 meters; multi-stage pump in the single Pump head needs to be equipped with two-stage motor, the impeller can be increased by increasing the number of four motor, which can improve pump life and reduce unit noise, but the multi-stage pump repair relative single-stage pump is difficult a little. 3, the pump actually needs less than 125 meters head, according to pump room area, pump price (multi-stage pump generally higher than the single-stage pump price), and other factors considering the choice of single-stage pump or multi-stage pump. 4, with technological advances, single-stage impeller pump can improve the pump lift by increasing the pump speed, instead of multi-stage pump, but the price is a little expensive. In summary, the single-stage pump is only an impeller ion pump, and multi-stage pump is more than two impeller ion pump, single-stage pump head is only 125 meters, multi-stage pump head can exceed 125 meters, The price of a single-stage pump will be higher than that of a multi-stage pump. All in all, different places have different requirements for their choices, but as long as we understand the difference, it is easier to choose the product. Related articles: Centrifugal pump features Centrifugal pump performance parameters