1、 The type and performance of the selected pump meet the requirements of process parameters such as unit flow, head, pressure, temperature, medium viscosity, NPSH, suction head, etc.
2、 It must meet the requirements of medium characteristics.
1. For pumps conveying inflammable, explosive, toxic or valuable media, the shaft seal shall be reliable or leakage free pumps shall be used, such as magnetic drive pump, diaphragm pump and shield pump.
2. For pumps conveying corrosive media, it is required to use corrosion-resistant materials for components in contact with the media, such as AFB stainless steel corrosion-resistant pump and CQF engineering plastic magnetic drive pump.
3. For the pump conveying the medium containing solid particles, wear-resistant materials shall be used for the parts in contact with the medium, and clean liquid shall be used for flushing the sealing if necessary.
3、 High mechanical reliability, low noise and small vibration.
4、 In economy, the total cost of equipment cost, operation cost, maintenance cost and management cost should be considered comprehensively.
5、 Centrifugal pump has the characteristics of high speed, small volume, light weight, high efficiency, large flow, simple structure, no pulsation of infusion, stable performance, easy operation and maintenance, etc. Therefore, centrifugal pump should be selected as far as possible except for the following situations: when there is measurement requirement, metering pump should be selected.
1. When the requirements of lift are very high, the flow is very small and there is no suitable centrifugal pump with small flow and high lift, the reciprocating pump can be selected, and the vortex pump can be selected if the cavitation requirements are not high.
2. When the lift is very low and the flow is large, axial flow pump and mixed flow pump can be selected.
3. When medium viscosity is high, rotor pump or reciprocating pump (gear pump and screw pump) can be selected.
4. The air content of the medium is 75%, and the flow and viscosity are small, so the vortex pump can be selected.
5. In case of frequent start-up or inconvenient pump filling, pumps with self-priming performance shall be selected, such as self-priming centrifugal pump, self-priming vortex pump and pneumatic (electric) diaphragm pump.