October 05, 2025

The proper choice of metering pump should pay attention to several elements

What information do you need to properly select a metering pump? 1. The type of liquid being measured, including its flow rate. 2. The main characteristics of the liquid, such as chemical corrosiveness, viscosity, and specific gravity. 3. The system's back pressure, which affects the pumpâ€™s performance. 4. The suction height that the pump must handle. 5. Additional features required, such as analog control, pulse control, flow monitoring, or timer functions. What are the main advantages of an electromagnetically driven metering pump? Electromagnetically driven metering pumps have only one moving partâ€”the armature shaft. This simplicity reduces wear and tear, making them more reliable and easier to maintain. These pumps are ideal for low-flow and low-pressure applications and can compensate for voltage fluctuations effectively. They are also known for their precision and long service life. What are the benefits of adjusting the frequency versus the stroke length in a metering pump? By calibrating the pump, you know the exact dosage per stroke. The total dosage is calculated by multiplying the dosage per stroke by the frequency (dosing = dosage per stroke Ã— frequency). When frequency is adjusted, the total dosage changes proportionally (e.g., 50% frequency = 50% dosage). With external pulse or analog control, the dosage can be smoothly adjusted from minimum to maximum within seconds. Compared to motor-driven stroke length adjustments, this method is more cost-effective and offers greater flexibility. How do you use the performance curve of a metering pump? 1. Locate the performance curve that matches your selected metering pump model. 2. Identify the current back pressure in the system and mark it on the curve. 3. Determine the correction factor by aligning the back pressure value (in bar) with the curve and reading the corresponding correction factor on the left side. 4. Divide the required dosage by the correction factor to get the actual dosage in mL/min or L/h. 5. Place the calculated value on the dosage scale. 6. Use a ruler to find the appropriate stroke length and frequency settings for optimal performance. This process ensures accurate dosing even under varying operating conditions, helping you achieve consistent and reliable results.