Why Is It Harder to Maintain Accuracy in Metering Pumps at Low Flow Rates?

Metering pumps are widely used in chemical dosing, water treatment, and industrial processes because they can deliver fluids with precise and controllable flow rates. However, in practical applications, many engineers notice that maintaining accuracy becomes more difficult when the pump operates at very low flow rates.

Several factors contribute to this phenomenon.

1️⃣ Small Stroke Volume

When a metering pump operates at low flow, the stroke length or stroke frequency is reduced. The amount of liquid delivered per stroke becomes very small, which means even minor mechanical variations can significantly affect the final flow accuracy.

2️⃣ Liquid Compressibility Effects

At low flow rates, the volume of liquid delivered in each stroke is minimal. Any compressibility of the fluid or pressure fluctuation in the system can cause noticeable differences between theoretical and actual flow.

3️⃣ Check Valve Response

Metering pumps rely on inlet and outlet check valves to control fluid movement. At low flow rates, the opening and closing behavior of these valves becomes more sensitive, and small delays or incomplete sealing can lead to flow instability.

4️⃣ Proper Pump Selection Matters

To maintain better accuracy, metering pumps should ideally operate within their optimal working range rather than at extremely low flow levels. Proper system design and pump selection are also essential for stable dosing performance.

Manufacturers such as Shanghai Shangcheng Pump & Valve Manufacturing Co., Ltd. provide industrial pumping solutions designed to improve reliability and performance under different operating conditions.

Learn more about related pump products here:

https://www.scpv.cn/cilibeng/