1, the pump process.
The pump flow, head and other basic parameters should be reasonably determined according to the process requirements. It is generally believed that the normal wear and tear of the pump and changes in rotational speed may lead to a decrease in head. Therefore, in the selection of the pump, the pump head can have 2% ~
5% of the margin, but not more than 10%. the basic principle is to ensure that the pump operates in a high range of efficiency. In addition, by calculating the cavitation margin of the device, you can obtain information about the inlet state of the corrosion-resistant pump.
2, the corrosiveness of the medium and the choice of materials.
There are many types of chemical media with different properties, which require accurate characteristic parameters, especially corrosivity, concentration, volatility, vaporization pressure, viscosity, density and so on. These properties are closely related to the choice of materials, not only metal materials, non-metallic materials and media.
3, medium temperature.
Temperature has a great impact on the chemical pump structure selection, such as corrosion-resistant pump body support, cooling (or insulation) system design, etc., these are closely related to the temperature of the medium being transported.
4, spindle seal and its auxiliary system selection.
According to the actual case analysis, the failure of the unit by the spindle seal caused by a high proportion of some occasions can reach thirty ~ forty percent, so the choice of spindle seal is very important.