What information is needed to properly select the metering pump? 1, is the measurement of liquid flow. 2, was measured the main characteristics of liquids, such as chemical corrosion, viscosity and specific gravity. 3, the system's back pressure. 4, the appropriate suction height. 5, the other options needed, such as analog control, pulse control, flow monitoring and timer. What are the main advantages of the electromagnetic drive metering pump? Electromagnetic drive metering pump has only one moving part - the armature shaft. In general, the less moving parts, the more reliable the metering pump works. Metering pump is ideal for low-flow, low-pressure workplaces, and good compensation in the supply voltage fluctuations. What are the advantages of metering pumps with fixed stroke length and varying frequency compared to metering pumps with fixed frequency and varying stroke length? With this correction, the dosing amount per stroke is known. The total dosage can therefore be calculated (dosing = dosing per stroke * frequency). The total dosage is linear with frequency (50% frequency = 50% dosing). Through external pulse or analog control, dosage can be transferred from minimum to maximum in one second. In addition, it is much less costly than motor-driven stroke length adjustment. How to use the performance curve of the metering pump? 1, Find the performance curve of the selected metering pump. 2, in the chart below indicate the current back pressure. 3, determine the correction factor, take the bar as the unit of the back pressure value, extending up to the curve, at the cross point vertically to read the correction factor value. 4. Divide the amount of dosing required by the correction factor to give the value in ml / min. Or L / h. 5, put the calculation results in the middle of the dosage scale. When placing this value on the dosing scale, a ruler can be used to find the stroke length setting and stroke frequency setting.