Centrifugal and positive displacement pumps each offer distinct advantages in slurry service, and the right choice depends on solids content, viscosity, and operating conditions. Centrifugal pumps deliver high flow rates and are widely used because of their simple hydraulics, but they require slurry-specific adaptations such as wear-resistant liners, open or semi-open impellers, and controlled operating speeds to reduce erosion. Their efficiency can decline as solids loading increases, and they typically need flooded suction to operate reliably.
Positive-displacement pumps, including air-operated double-diaphragm (AODD) models such as those from Iwaki Air, excel when slurries are highly viscous, shear-sensitive, or contain large or sharp particles. They provide consistent flow regardless of discharge pressure, offer self-priming and dry-run capabilities, and tolerate abrasive conditions well, though they generally deliver lower flow rates and require periodic diaphragm or valve maintenance. For a detailed comparison of strengths, limitations, and selection criteria, see Slurry Handling Explained: How to Choose & Operate Slurry Pumps.
