Are gear pumps self-priming?

Gear pumps are not self-priming, which is why the answer is "No." Self-priming pumps have the ability to lift liquid from a lower level and remove air from their suction line, enabling them to start pumping without needing any additional fluid in the casing. Gear pumps, however, rely on a continuous influx of fluid to maintain operation and do not generate the necessary suction to prime themselves effectively when empty. This inability to create a vacuum means they need to be filled with liquid before they can start pumping.

This characteristic is crucial for many applications, as it necessitates proper installation and operational practices to ensure that the pump is adequately filled with liquid prior to use.