【2026 Pump Selection】Examples of pump selection
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Taking the process of a certain concentrate system as an example: the designed flow rate of the pump is 6000 kg/h, with the concentrate being transported from the lower-level concentration tank B101 (0.5 barg) to the higher-level treatment tank B102 (ΔH: 3+10 m). The layout of the pipes on-site has been determined (the pipe lengths, as well as the number of fittings and valves, are shown in the calculation table). Calculate the pipe pressure drop in this concentrate pipeline system and the selection parameters for the transfer pump; the flowchart is shown above.
Following the calculation steps and formulas from the previous article (【2026 Pump Selection】Pump Selection and Pipeline Pressure Drop Calculation), by entering the relevant parameter values into the prepared Excel sheet as required, it is possible to calculate the flow rate of materials in each branch, the pipeline pressure drop, the effective net positive suction head of the piping system, the pump’s head, and its shaft power. The details are shown in the calculation table below.
This calculation sheet is divided into three sections: fluid data, pump and pipeline pressure drop calculations, and pump parameter calculations. All you need to do is fill in the fluid property data in red text, as well as information such as the diameter and length of the pipelines, the number of fittings and valves, as well as the pressure and height data of the suction tank and the target tank; the calculations will then be performed automatically, which is very convenient.
The following response is for reference: I. Steps for the design and calculation of pump and pipeline systems: 1. Estimate the required flow rate of the pump based on the material demand and the time requirements of the process, then add a margin of 15~20% to determine the designed flow rate of the pump； 2. Determine physical properties such as density, viscosity, and saturated vapor pressure of the material to be pumped based on its type ； 3. Based on the process conditions, process flow diagrams, and on-site piping diagrams (or pipe layout drawings), determine the location of the equipment as well as the direction of the pipes (pipe lengths, valves, fittings, etc.) ；
4. Divide the system into sections using the equipment (suction tanks, pumps, destination tanks, etc.) as nodes, identify the names of each pipe section; if there are branch pipelines, allocate the material flow rates to each branch according to the process conditions (for parallel connections, V = V1 + V2 + V3 + …; for series connections, V = V1 = V2 = …)； 5. First, estimate the required pipe diameter based on the economic flow velocity of the fluid, and then select inlet and outlet pipes of appropriate sizes; generally, the pump suction pipe is one size grade larger than the discharge pipe, and the actual flow velocity is calculated accordingly ；
6. Based on the pipeline layout diagram (single-line diagram), calculate the straight-length of each section of pipeline, the number of fittings (elbows, tees, etc.) and valves (including check valves and control valves), as well as the equipment located along the pipeline; additionally, determine the height difference between the starting and ending points of each pipeline section； 7. Calculate the Reynolds number of fluid flow based on the flow velocity of each pipeline, as well as the density and viscosity of the material, to determine whether the flow is laminar or turbulent; then calculate the friction coefficient based on the type of flow and the roughness of the pipeline ； 8. Calculate the frictional pressure drop, local pressure drop, static pressure drop, total pressure drop, and pressure drop per 100 meters for each section of pipeline using the pipeline pressure drop formula ；
9. Determine the pressure within the pump’s suction side equipment (the pressure must be reduced by this value in the pump’s suction pipe) and the discharge side equipment (the pressure must be increased by this value in the pump’s discharge pipe)； 10. Calculate the effective net positive suction head of the pump piping system based on the pressure drop in the pump inlet pipeline, the pressure drop across the equipment, and the saturated vapor pressure of the material at the transportation temperature ； 11. Calculate the head required by the pump based on the total pressure drop of the piping system, and then determine the shaft power of the pump using flow rate, head, and the density of the material ； 12. Ultimately, the manufacturer can be approached for model selection based on the various parameters of the pump that have been calculated. Using the efficiency η and Cosθ of the pump as provided by the manufacturer, it is possible to determine the effective output power of the motor, thereby allowing for the selection of an appropriate motor power.