Priming in centrifugal pumps is the process of filling the pump casing with the fluid to be pumped, removing any air from the casing, and creating a seal between the impeller and the casing. Priming is necessary for centrifugal pumps because most of them are not self-priming, meaning that the pump casing must be filled with liquid before the pump is started, or the pump will not be able to function. If the pump casing becomes filled with vapors or gases, the pump impeller becomes gas-bound and incapable of pumping. Priming is done to put the pump into working order by filling or charging it with water.

Priming is important because a poorly primed pump can result in reduced efficiency, increased energy consumption, and even damage to the pump itself. On the other hand, a properly primed pump can operate more efficiently, with lower energy consumption and longer lifespan. Different pumps and different system setups require different steps to prime, so it is important to refer to the pump manual for more information.

In summary, priming in centrifugal pumps is the process of filling the pump casing with the fluid to be pumped, removing any air from the casing, and creating a seal between the impeller and the casing. It is necessary for centrifugal pumps to function properly and to avoid damage to the pump. Priming is important for pump efficiency and longevity, and the steps to prime a pump may vary depending on the pump and system setup.