PUMPCALC is a Centrifugal Pump Analysis program.

It can be used to predict the performance of one or more centrifugal pumps, at various impeller sizes, speeds and series or parallel configurations.

The following are the main features of PUMPCALC:

  • Single pump performance- Impeller size and speed changes
  • Multiple Pump Performance – Series and Parallel Configuration
  • Viscosity Corrected Pump Performance – Hydraulic Institute method.
  • Pump Head Curve versus Pipe System Head Curve- Operating point
  • Screen and Printer Graphic Plots


The main data needed for running PUMPCALC is the pump performance data.
This consists of sets of values of Flow rate (or capacity), Head and Efficiency for a particular pump, for a specific impeller size and speed.

Normally, you will need to get this information from a pump catalog. The number of sets of Flow, Head and Efficiency values are limited to between 3 sets of points (minimum) and 15 sets of points (maximum). The data points taken off of a manufacturer’s pump curve must cover the entire range of flow rate permissible for the specific pump.

Extrapolation can be made but may result in inaccurate results.

Pump data files are saved under a name with PMP file extension, such as Compton.pmp

To create a new pump file, Choose File from the main screen above followed by New and enter data in the blank spreadsheet displayed.

In addition to the three columns of data for Flow rate, Head and Efficiency you may also specify the pump impeller size, speed and the number of stages in this pump.

After entering all data, choose File/Save from the menu bar and save the pump curve data in a file name of your choice.

The Advanced button above is for entering a single design point data for a pump, in order to create a typical pump curve.

For example, if the desired design point is at 1000 gal/min, 2500 ft head at 80% efficiency, you may enter this data for PUMPCALC to automatically create a pump curve based on this design point, as shown in screen.

After entering data for the design point as above, and selecting a name for the pump file, click the Create file button. PUMPCALC will automatically create a pump curve for the design point specified as indicated in the screen. It can be seen that the pump curve data have been created around the best efficiency point (BEP) specified above.

The Interpolate.. button located on the right side of the pump curve screen is used to interpolate data from a given pump curve.

Upon clicking this button the following screen is displayed.

From this screen, you may interpolate the pump curve data for different flow rates.

For example, at a flowrate of 1100 gpm, the interpolated head and efficiency are 2369.26 ft and 79.27 % respectively.

The brake horsepower for water is also calculated and displayed as indicated above.

Features of PUMPCALC

There are four main features of PUMPCALC, as indicated by the four buttons arranged vertically down on the left hand side of the main screen, shown above.

The first button titled Single Pump is for calculating the performance of a single pump, determining its performance at different impeller diameters and speeds and generating a graphic plot of the Head versus Capacity, Efficiency versus Capacity and BHP versus Capacity curves.
Also, for a given Design Point (Q-H value), it can be used to calculate the new impeller size or speed.

The second button titled Multiple Pumps is for calculating the combined performance of two or more pumps in series or parallel configuration.

The third button titled Viscosity Correction is for predicting the performance of a pump when pumping viscous liquids. For high viscosity liquids, the given water performance curve is used in conjunction with the built-in Hydraulic Institute charts to estimate the viscosity corrected pump performance.

The resultant performance curves may be plotted on the screen as well the printer.

The fourth button titled System Curve is for calculating the System Head curve versus the pump curve, when the pipe system characteristics are given.
The point of intersection between the pipe system head curve and the pump curve can be determined using this option. For a given pipeline diameter, length and elevations, the system head curves can be generated for different liquid properties and the point of intersection of the pump curve and the pipeline system curve can be determined. Screen graphics of the combined pump performance versus the system curve are also generated.

The Five Easy Steps to get started with PUMPCALC is displayed when the program is launched, as shown in the image.

Choosing the Single Pump option displays the following screen.

Using Affinity Laws, the pump performance at different impeller diameters and speeds can be calculated, from the given pump curve data based on a particular impeller size and speed.

Also, for a specific design point( head and capacity values), the program can predict the impeller size or pump speed required, based on the existing impeller size and speed.

Clicking the Options.. button in the above screen displays the following window for specifying the required design point (Q-H values).

Clicking the Multiple curves.. button displays the following window for inputting the diameters or speeds required for generating a family of Head-Capacity curves, based on Affinity Laws.

A family of pump Head versus Capacity curves may be generated from given pump data at various impeller sizes or pump speeds, using the Affinity Laws. The results of the above are shown in a graphic plot as follows

If the impeller diameter variation option were chosen, instead of speed variation, the following family of H-Q curves will be generated

Clicking the Multiple Pumps button from the main screen displays the following window for entering pump data to calculate the combined pump performance in Series or Parallel configuration.

After entering the data for pumps, clicking the OK button will display the calculated results for combined pump performance. The screen graphics of the combined pump performance will also be displayed, based on the plot option chosen from the following screen.

The combined pump performance may be plotted as follows

Clicking the Viscosity Correct button displays the following window for inputting the pump and liquid data for performing the viscosity correction, using the Hydraulics Institute chart method.

Enter the file name of the water performance curve and the file name for storing the viscosity corrected performance data. Press F3 to view a directory listing of available pump data files to choose from.

Only those pump files with a PMP extension will be displayed. Change the default extension from *.PMP to *.* to view all files. The file name for the viscous curve, by default has the letters VSC added to the pump file name.
For example, if the water curve is Pump1.pmp then the viscous curve will be shown as Pump1vsc.pmp

The viscous performance calculated requires the use of the Best Efficiency Point (BEP) from the water curve.
This is defined as the point on the water performance curve with the maximum efficiency.
The flow rate, head and efficiency at this point on the curve is used as the starting point for viscosity corrected performance calculations. The BEP values may be specified in the appropriate fields or you may have PUMPCALC calculate the BEP by interpolation. After entering all data, click on the Calculate button to start calculations.
Based on the Hydraulic Institute Charts, the water performance curve will be corrected for the given liquid viscosity.
The water performance curve and viscous performance curve calculated will shown side by side in spreadsheets as shown below.
It must be noted that the results displayed are for only the four sets of data(60% BEP, 80% BEP , 100% BEP and 120% BEP) for both water curves as well as the viscous curves, in accordance with the Hydraulic Institute method.

Once the viscous performance is calculated, additional points on the viscous curve can be determined by interpolation. If the water performance and the corresponding viscous performance are desired at a particular flow rate, enter this value in the Flow rate field as shown above and click the Calculate button. The performance on both curves at the specified flow rate will be calculated and displayed on the spreadsheets, in a highlighted color. Similarly, additional data points on both curves can be calculated. Remember that extrapolating beyond the limits of the performance curve, though feasible, may be inaccurate.
Due to the nature of the Spline Interpolation method used, extrapolation may, in some cases yield incorrect results. However interpolation is generally quite accurate. The calculated viscous performance curve is saved in a data file as shown in screen above. This curve information may subsequently be used with Single Pump option to determine other performance characteristics using affinity laws.
Clicking the Plot button on the viscosity correction screen above opens another windows to choose the type of plot. The calculated water performance and viscous performance curves can be plotted by clicking one of the Option buttons.

Clicking the System Curve button on the main PUMPCALC screen displays the following window for inputting the pump and pipe data for calculating the System Head curve and operating point.
The latter is the point of intersection between the system head curve and the combined pump performance curve. The liquid properties data input screen should also be checked to ensure that the correct liquid data (specific gravity and viscosity) is used in these calculations.

Clicking the Options.. button in the above screen displays the window for inputting the additional pipe data needed for generating the system head curve as below

For calculating the pipe system head curves, the pipeline data (distance, elevation, diameter, wall thickness and pipe roughness) are input and stored as a data file. The liquid specific gravity and viscosity are input under the separate Liquid screen, from the pull down menu on the main PUMPCALC screen. The pump suction pressure, pipe delivery pressure, maximum allowable pipe pressure and the pressure drop formula are also input in the screen above.

Alternatively, instead of pipe data above, the system head curve may be directly input. This option allows you to enter the Flow rate versus System head data for plotting against the pump head curve. If the System Head curve data is input, PUMPCALC ignores the pipe data and uses the system head curve data, without calculating the pressure drops.

When used with the given pipeline data, in the absence of system head curve information, pipeline pressures are calculated for various flow rates to generate the System Head curve.
Hydraulic calculations are performed based on the chosen pressure drop formula, such as Colebrook-White, Moody, Hazen-Williams, MIT or Miller equation for isothermal conditions of flow. The output consists of the pump operating flow rate, discharge pressure, efficiency and horsepower at the operating point.
Screen graphics of the combined pump curve and system head curve are also generated as shown below.


WARNING: Although PUMPCALC provides an option of extrapolating pump curve data beyond the values input by user, this can some time result in inaccurate results. Use this option with caution!

Always try to include sufficient points (up to a maximum of 15 sets) from the manufacturer’s pump curve data covering the full range of flow rates anticipated. Do not depend on PUMPCALC to extrapolate performance data beyond the range of values input!

Similarly, if using the System Head curve input option, provide enough data for the system head curve covering the full range of flow rates anticipated, including the maximum pump flow rates permissible for the pump curves selected.

English and Metric units of calculation are available.

A toolbar consisting of icons for commonly used menu items such as File – Open, Save, Print, Calculate, etc. is available below the menu bar. These menu items or commands can be accessed by clicking on the icons. As the mouse is moved over an icon, a tool tip help appears explaining the function of each icon on the toolbar.

You can use the e-mail icon on the toolbar to send the results of calculations to a colleague or contact SYSTEK in the event of a problem with the software. The Notepad icon is to launch Windows Notepad, if you want to do some quick text editing or cut and paste results.

The pull down menu under Units displays the following for English units

and the following choices for the Metric units.

Please note that all pump data files should conform strictly to the specified format as explained in the user manual. Each pump data file consists of flow rate, head and efficiency values stored in a comma delimited, text file format. You may view a pump data file in a text editor, such as the Windows Notepad. However, to edit or make changes to a pump data file, use only the spreadsheet editor provided with the PUMPCALC software. Refer to the sample data file named DEMO.PMP included with PUMPCALC.

Creating and Editing Data Files
Data files are created using the built-in spreadsheet and saving the data in a text file. If you want to use a text editor, such as Windows Notepad, make sure the data format strictly conforms to the format shown in the sample pipe and pump data files. The spreadsheet approach automatically takes care of the format.

From the main screen menu bar, choose File followed by New and a blank spreadsheet opens up. This window is used to input the pump data to create a new data file.

For Pump Data File:
Enter the pump information namely flow rate, head and efficiency under appropriate columns, such as 0,3185,0.01 etc. as shown in the first screen at the beginning of this document. A maximum of 15 points (rows of data) are allowed in the pump data file.

You may obtain a screen plot of the pump curve by clicking the Plot icon. If a printed graphic is also required, click on Printer output button. Make sure you save the pump curve data first, before clicking the Plot button. You may also calculate interpolated values from the pump curve by clicking the Calculate button on the right side of the pump curve spreadsheet.

For Pipe Data File:
For the System Curve option, you may want to create a pipe data file or a system curve data file. This is done by double-clicking on the pipe file name in the Pump Curve System Curve Analysis screen. A screen will be displayed with a spreadsheet for entering the pipe data as shown previously.

Enter the pipe line information namely distance, elevation, pipe diameter, wall thickness and roughness under appropriate columns, such as 0,100,14,.25, 0.002. as shown in a previous screen. A maximum of 99 points (rows of data) are allowed in the pipe data file.

After all data are input, choose FILE followed by Save As. Type the file name to be saved under.

********************** DEMO INFORMATION **************************
In the DEMO version of PUMPCALC, there are limits to the input data.
The limits are as follows:
Flow rate – 100 to 300 gpm (20 to 60 m3/hr)
Head – 100 to 500 ft (30 to 150 m)
Pipe Sizes – 16 in (400 mm)
Maximum set of data points – 5 for pump curve
For viscosity correction calculations:
Sp. Gravity: 0.9 Viscosity: 1000 SSU
For system head calculations:
Sp. Gravity: 0.9 Viscosity: 10 CST
Pipe size: 16″ ( 400 mm)
Pipe length: 100 miles(160 km)
Maximum set of pipe data points: 10