What can occur when pumping at a low residual pressure while being supplied by other apparatus?

When pumping at a low residual pressure while being supplied by other apparatus, cavitation of the pump can occur. Cavitation happens when the pressure within the pump drops below the vapor pressure of the liquid being pumped, leading to the formation of vapor bubbles. These bubbles can collapse violently when they move into higher-pressure areas of the pump, resulting in potential damage to the impeller and other internal components.

In situations where other apparatus are supplying water, their flow characteristics and the interaction with the pump can lead to fluctuations in system pressure. If the residual pressure is too low, the pump may struggle to maintain adequate suction pressure, thereby increasing the likelihood of cavitation. This is particularly critical because cavitation not only affects the efficiency and performance of the pump but can also lead to costly repairs and downtime.

Understanding the implications of low residual pressure and its influence on pump operation is essential for effective fire engineering practices, as maintaining proper flow and pressure is vital for ensuring the reliability of firefighting operations.