A metering dosing pump (also known as a chemical dosing pump or proportioning pump) is a type of positive displacement pump designed to inject a precise and controlled volume of fluid, such as a chemical, into a stream of water, gas, or steam over a set period. The primary function of these pumps is to ensure high accuracy and repeatability in the delivery rate, which is crucial for processes that require strict chemical concentrations, such as water treatment, chemical manufacturing, and pharmaceuticals. Metering dosing pumps operate by a reciprocating motion, which draws in a specific volume of liquid during the suction stroke and then forces that exact amount out during the discharge stroke. Key working principles: Positive Displacement: They capture a fixed, predetermined volume of fluid in a chamber and physically push it out with each cycle. This makes their flow rate largely independent of the discharge pressure, a major advantage over centrifugal pumps. Stroke Control: The flow rate is typically adjusted by controlling two parameters: Stroke Length: Changing how far the internal component (piston or diaphragm) moves, which directly changes the volume of fluid displaced per stroke. Stroke Frequency/Speed: Changing how often the strokes occur over time. Check Valves: One-way check valves on the inlet (suction) and outlet (discharge) ensure the fluid flows in the correct direction and prevent backflow. What kind of fluid are you looking to dose?