# Auto-Sizing Centrifugal Pumps

From v3.31 onwards, FluidFlow includes a powerful Auto-Size feature which allows engineers to automatically size a range of elements including Centrifugal Pumps. This series of examples demonstrates how these pumps can be automatically sized, based on a design flow rate or design duty pressure rise. The system used in this example has a total pipe length of 55.0 m, the pipework is 50A JIS 50mm steel and the system experiences an elevation change of 10.0 m. A copy of this model can be found in the folder: "QA Equipment Sizing". Auto-Sizing Centrifugal Pumps - Design Flow. Set the Automatically Size field for the pump to "On" and enter a Design Flow rate of 2.7754 kg/s. Figure 1 shows the data entry for the pump and Figure 2 gives an overview of the performance of this device in this system. Figure 1: Data entry for Auto-Sizing a Centrifugal Pump (Size for Flow). Figure 2: Auto-Sizing a Centrifugal Pump (Size for Flow). From this analysis, we have established the pump operating performance. The duty pressure rise and NPSHa has been calculated as 118765 Pa (12.1 m fluid) and 10.0 m fluid respectively. Auto-Sizing Centrifugal Pumps - Design Duty Pressure Rise. Set the Automatically Size field for the pump to "On" and enter the Design Duty Pressure Rise rate of 118765 Pa as established in the first simulation (Figure 2). The Input Editor for the pump should now appear as shown in Figure 3. Figure 3: Data entry for Auto-Sizing a Centrifugal Pump (Size for Pressure Rise). Figure 4 shows the calculated results for the pump. As we can see, FluidFlow has established a mass flow rate of 2.7754 kg/s and a NPSHa of 10.0 m fluid, i.e., exactly matching the results from Figure 2. This element has therefore been automatically sized successfully using both available sizing options. Using this data, we can now select a suitable pump model from the database or request a proposal from a vendor. Figure 4: Auto-Sizing a Centrifugal Pump (Size for Pressure Rise). For further information, a detailed example of automatically sizing components is available at: Design Examples | Auto Equipment Sizing.