On the basis of grasping the basic data of water pump selection, the following aspects should be paid attention to during the selection of corrosion-resistant pump:
1) Process flow. According to the requirements of the process, reasonably determine the flow and head of the pump and other parameters. Generally, the normal wear and the change of the speed of the pump may reduce the head, so the head of the pump can have a margin of 2% - 5% when selecting the pump. But the maximum can not exceed 10%. The basic principle is to ensure that the pump operates within the high efficiency range. In addition, through the process of anti-corrosion pump, the information of pump inlet condition can be obtained for the calculation of NPSH of equipment.
2) Corrosive and material of medium. Because of the complexity of chemical medium varieties and different properties, precise characteristic parameters, especially corrosive, concentration, volatility, vaporization pressure, viscosity, density, etc., are required. These properties are closely related to the selection of materials, not only metal materials, but also the interaction between non-metal materials and media.
3) The temperature of the medium. Temperature has a great influence on the structure selection of chemical pumps, such as the design of pump support, cooling (or insulation) system, which are closely related to the temperature of the transported medium.
4) Selection of main shaft seal and its auxiliary system.
According to the analysis of practical cases, the unit problems caused by the main shaft seal account for a high proportion of the total problems, which can reach more than 30% - 40% in some cases. Therefore, the selection of the main shaft seal is very important. In addition to the physical and chemical properties of the medium, the two main parameters, the pressure and the temperature of the sealing cavity, should also be selected.