What occurs if the discharge pressure is too low?

When the discharge pressure is too low, the pump may draw in insufficient fluid from the source, which can lead to a condition known as cavitation. Cavitation occurs when vapor bubbles form in the liquid being pumped due to low pressure; these bubbles collapse violently when they reach a higher pressure area within the pump. This collapse can cause significant physical damage to the internal components of the pump, such as impellers and casing, leading to decreased performance or even total failure of the pump.

The other options, while related to pump operation, do not accurately describe the consequences of low discharge pressure. For example, if discharge pressure is low, the flow rate generally does not increase; instead, it may become erratic or drop. Pump efficiency would likely decrease rather than improve, as the system would not operate within its optimal design parameters. Similarly, while engine efficiency can be affected by multiple factors, low discharge pressure does not inherently lead to a decrease in engine efficiency, as this is more related to fluid dynamics and pump performance.