On a pump curve, which items are plotted on the vertical axis?

• A. Capacity
• B. Temperature
• C. Head, power, and efficiency
• D. Volume

Answer: (C)

When reading a pump performance curve, you examine how the pump behaves as the flow rate changes. The horizontal axis represents flow (capacity), while the vertical axis is used to show the pump’s performance in terms of head. Along with head, the chart also includes curves for power and efficiency as functions of flow. This lets you see, at any given flow, how much head the pump develops and how much power it consumes, plus how efficiently it operates. The other options—capacity and volume—are not plotted on the vertical axis; capacity is on the horizontal axis, and temperature isn’t a standard metric shown on a basic pump curve.