What is a pump’s performance curve

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What is a pump’s performance curve? What aspects are included? What is its function? The curve that shows the relationship between the main performance parameters is generally referred to as the pump’s performance curve or characteristic curve. Essentially, the pump performance curve represents the external manifestation of the behavior of the liquid within the pump, and it is determined through experimental measurements. The characteristic curves include: the flow rate – head curve (Q – H), the flow rate – efficiency curve (Q – η), the flow rate – power curve (Q – N), and the flow rate – NPSH curve (Q – NPSHr). The purpose of these curves is to allow, for any given flow rate of the pump, the determination of corresponding values for head, power, efficiency, and NPSH. This set of parameters is referred to as the operating conditions, or simply the operating point. The operating condition at which a centrifugal pump achieves its highest efficiency is known as the optimal operating point, and this point is usually also the design operating point. The rated parameters of a conventional centrifugal pump coincide with or are very close to the design operating point and the optimal operating point. Operating within the efficient range in practice not only saves energy but also ensures the proper functioning of the pump; therefore, it is quite important to understand the performance parameters of the pump.