Flow rate , Q
The flow rate of a pump is defined by the amount of liquid that is being discharged by the pump per unit time. Some commonly used units of flow rate are l/s, l/min, m³/h, and gal/min. The flow rate of the centrifugal pump is usually expressed on the horizontal axis, as shown in the figure. The flow rates commonly identified on a pump curve includes the “rated flow rate” and the “minimum required flow rate”.