1, determine the pressure: The rated pressure of the selected metering pump is slightly higher than the actual maximum pressure required, generally higher than 10 ~ 20%. Do not select the metering pump to select too high, high pressure will waste energy, increase equipment investment and operating costs.
2, determine the flow: the selected metering pump flow should be equal to or slightly greater than the process required flow. The metering pump flow rate is preferably in the range of 30 to 100% of the metering pump's rated flow range. At this time, the repetitive reproduction accuracy of the metering pump is high. Considering economy and practicality, it is recommended that the actual required flow of the metering pump is selected to be 70 to 90% of the rated flow of the metering pump.
3, determine the pump head (hydraulic end) Material: After the specific model specifications of the metering pump is determined, and then select the material of the over-current part according to the properties of the over-current medium, this step is very important, if it is improperly selected, it will cause the medium corrosion damage. Overcurrent components or media leakage contamination system.
4. Other aspects: The general working temperature of the metering pump is -30 ~ 100 °C, and the working temperature range of the special metering pump is wider (such as the high-temperature liquid metering pump with insulation jacket, its delivery temperature can reach 500 °C). For the particle size of the media, we require that it should be less than 0.1mm. For media larger than 0.1mm, we can specifically change the overcurrent structure of the pump to meet the needs. The viscosity of the medium should generally be 0 to 1000 mm/s, and the special metering pump can reach 6000 mm2/s. The flow rate of the mechanical diaphragm metering pump is the maximum flow rate measured under the rated pressure rating (clear water delivery at room temperature. When), if the pressure drops, the output flow will be higher than the calibration.