When flow testing a gear pump, if it produces 250 lpm (55 gpm) at low pressure but drops to 150 lpm (33 gpm) at normal working pressure, what is recommended?

In the scenario presented, a gear pump is tested and shows a significant drop in flow rate when moving from low pressure to normal working pressure. It produces 250 liters per minute (lpm) at low pressure but drops to 150 lpm at normal working pressure. This indicates an issue with the pump's ability to maintain its designed performance under load.

A gear pump is expected to provide consistent flow rates across various pressure conditions. The drop in flow from 250 lpm to 150 lpm signifies a loss of efficiency or capability of the pump to perform adequately at the required operational pressures. This disparity often suggests that the internal components of the pump, such as gears, bearings, or seals, may be worn or damaged, resulting in leakage or cavitation, which directly impacts performance.

In practice, if a pump cannot maintain its rated flow at normal operating conditions, it is generally recommended to replace the pump. Continuing to use a pump that doesn't meet flow specifications can lead to inadequate system performance, increased wear on other components, and potential failure of the entire hydraulic system.

The other options do not address the fundamental issue of the pump's performance directly as clearly as replacing the pump does. Testing relief valve pressures might provide insight into system pressure-related issues