Why is it better to locate a pump below the level of the fluid?

Locating a pump below the level of the fluid is advantageous primarily because it allows for greater pressure head to be available at the pump's inlet. This arrangement increases the hydrostatic pressure acting on the fluid, which helps ensure that there is a consistent and adequate flow of fluid into the pump. When the pump is positioned below the fluid level, gravity aids in drawing the fluid into the pump, minimizing the risk of cavitation, where vapor bubbles form and collapse in the fluid stream, which can damage the pump and reduce efficiency.

In contrast, positioning a pump above the fluid level would require the pump to create a vacuum to lift the fluid, which demands more energy and can lead to issues with air entrapment and cavitation. By ensuring that the pump is below the fluid level, it relies on gravity to assist in fluid movement, leading to more reliable pump operation and better overall performance.