What is a pump curve and why is it important in selecting an irrigation pump?

• A. A graph of head versus flow; helps select a pump that meets system TDH and desired flow without overloading.
• B. A schedule of maintenance intervals for pumps.
• C. A schematic diagram of pump components.
• D. A chart of energy usage vs runtime.

Answer: (B)

A pump curve shows how much head (pressure) a pump can develop at different flow rates for a specific pump setup. It’s essential because you’re trying to match the pump’s performance to the system’s needs, namely the total dynamic head (TDH) and the desired flow. The operating point—the real-world flow the pump will deliver—is found where the pump curve intersects the system curve. You want that point to meet your target flow while the pump operates efficiently and without being overloaded. If you pick a pump that provides too much head for the needed flow, efficiency falls and energy use rises; if the pump is too small, it won’t reach the desired flow and will strain the pump. The other options describe maintenance schedules, component diagrams, or energy-usage charts, which don’t convey how a pump performs across different flows.