Pump Sizing

The Centrifugal (Rotodynamic) Pump Model offers the option of Sizing a pump. By entering a Pump Sizing Parameter, the corresponding operating conditions are calculated and displayed in the Pump Summary section of the Output window . By inputting a flow at a pump, determining the pump size requirements is straightforward. The Walk Through Examples have an example of using AFT Fathom to size a pump.

Pump Sizing with a Flow Control Valve

Using the sizing feature on a pump (fixing the flow rate) with a Flow Control Valve (which also fixes flow rate) downstream results in a Reference Pressure error - the system no longer has a unique solution. While the pump is being sized, the control valve must be temporarily defined as a Constant Pressure Drop Control Valve to avoid these errors. Read more about this in Role of Pressure Junctions - Detailed Discussion.

Suggest Pump & Intelliquip™

Once you have sized a pump, you can use the Suggest Pump feature which is opened from the Library menu > Suggest Pump or the Output Toolbar to find an actual pump that meets the requirements. The Suggested Pumps window allows you to specify search criteria and to select the libraries you want to search. Search criteria includes pump head, NPSH, and BEP proximity.

If you or a colleague has previously saved various manufacturer pump models and performance curves to a junction library that you have connected in the Library Manager, you can search this library to see if any saved pump curves meet the requirements. This is useful if an Enterprise-Wide Network Library System is set up for your company.

Click Search once the criteria and Source Library are defined (see below for instructions on using the Internet Library Source). Pumps that meet the criteria will be shown in the table below. The table can be sorted by proximity to operating head, BEP, or alphabetically. The Show Pump Curve button allows for quick viewing of the composite curve for a selected pump. The operating point is overlaid on the graph such that you can determine if the pump is a good fit. If the performance curve is determined to be appropriate for the model, the Apply Pump Data button can be used to open the Apply Pump Data window where one or more pump junctions can be updated to use the performance curve.

Intelliquip™ - In addition, the Internet Library Source allows you to pass operating point data to Internet hosted pump supplier websites which use Intelliquip™.

Select the Internet radio button under Source Library, and select Intelliquip from the dropdown menu.
Click Search to open the Intelliquip Search window.
Select Display Units and the Frequency of the electrical grid that the pump will operate on (60 Hz or 50 Hz).
Click Open Web Browser to be taken to the AFT Intelliquip landing page.
Select a pump supplier website.
Browse the catalog and adjust the search filters. Each supplier's website may operate differently and might require different data inputs to be adjusted.
Once a pump model is found to be appropriate, look for a download button and download the *.iqx file.
Return to the Intelliquip Search window in Fathom, click the radio button for Step 2, and click Open File(s).
Select the *.iqx file for the pump. The pump will now appear in the table.
Select the pump in the table, click Apply Pump Data, and update the desired junctions in the model. The Add to Library option allows you to save the pump curve to a connected library for future use.

For an example of pump sizing in Fathom, see the Sizing a Pump example.