Metering Pump vs Diaphragm Pump

A metering pump describes a duty: controlled, repeatable delivery. A diaphragm pump describes a pumping mechanism. Many metering pumps use a mechanically or hydraulically actuated diaphragm, so the terms are not opposites. Choose a metering design when repeatable chemical injection and adjustment are primary requirements. Diaphragm liquid ends provide separation between the chemical and drive, which is useful for corrosive, hazardous or leak-sensitive services. Plunger liquid ends can suit high pressure and clean liquids but require careful sealing review. For transfer rather than precision dosing, an air-operated double-diaphragm or another transfer pump may be more appropriate. Compare required accuracy, flow, pressure, suction conditions, solids, chemical compatibility and maintenance—not the name alone.