# Auto-Sizing Rotating PD Pumps

From v3.31 onwards, FluidFlow includes a powerful Auto-Size feature which allows engineers to automatically size a range of elements including Rotating PD Pumps. This series of examples demonstrates how these pumps can be automatically sized. To begin, a Varisco PD pump has been modeled in a 2 inch Schedule 40 steel pipeline with a total length of 18.28 M. Using the calculated information, we can benchmark our automatically sized element against this base model. Figure 1 shows the data entry for the Varisco PD pump and Figure 2 gives an overview of the performance of this device in this system. Figure 1: Data entry for Varisco PD Pump (Auto Size function set to Off). Figure 2: Varisco PD Pump Model (Auto Size function set to Off). From this analysis, we have established the pump operating performance. The flow rate and duty pressure rise has been calculated as 3.82 kg/s and 1.6 m fluid (15828 Pa) respectively and a NPSHa of 9.9 m fluid has been established. Auto-Sizing Rotating PD Pumps. Set the Automatically Size field for the pump to "On" and enter a Design Flow rate of 3.82 kg/s. Note, the field titled Pump Model has now been removed from the Input Editor. The Input Editor for the pump should now appear as shown in Figure 3. Figure 3: Data entry for Auto-Sizing a PD Pump. Figure 4 shows the calculated results for the pump. As we can see, FluidFlow has established a mass flow rate of 3.82 kg/s, a NPSHa of 9.9 m fluid and a duty pressure rise of 15828 Pa, i.e., exactly matching the results from Figure 2. This element has therefore been automatically sized successfully. Using this data, we can now select a suitable pump model from the database (Varisco PD Pump) or request a proposal from a vendor. Figure 4: Auto-Sizing a PD Pump. For further information, a detailed example of automatically sizing components is available at: Design Examples | Auto Equipment Sizing.