Method And Steps For Selecting Pumps

Jan 17, 2025

① List basic data

A Physical properties of the medium: medium name, specific gravity under transport conditions, viscosity, corrosion, etc.

B The medium contains solid particle size and content.

C Operating conditions: temperature; Pressure (inlet side equipment pressure, discharge side equipment pressure, discharge side piping pressure drop); Traffic (normal, minimum, and maximum).

D Location of the pump: ambient temperature; Altitude; Requirements for pipeline layout and elevation; The distance from the liquid level of the inlet and outlet equipment to the center of the pump and the equivalent length of the pipeline.

② Determine the flow rate and head

A Flow rate: When selecting a pump, the maximum flow rate should be considered; If only normal flow rate is given, a safety factor of 1.1 should be adopted according to the specific situation of the device and process. The above refers to volumetric flow rate.

B Head (or pressure difference): According to the arrangement of the pump, use the Bernoulli equation to calculate the head of the pump.

③ Select pump type and specific model of pump

Select the appropriate type of pump based on the characteristics of the medium, the determined flow rate and head, as well as relevant selection principles and the working range of the pump. Select the specific model of the pump from the samples and instructions provided by the pump manufacturer, and list the performance parameters (flow rate, head or pressure difference, efficiency, critical suction vacuum height or critical cavitation allowance) based on clean water.

④ Calculate the performance of the pump

Calculate the performance of the pump based on the actual situation. List the calculated performance parameters, and if they meet the process requirements, the selected pump is usable. If necessary, the calculated performance curve and pipeline system performance curve can be drawn to determine the working point of the pump.

⑤ Determine the geometric installation height of the pump

⑥ Calculate the shaft power of the pump

⑦ Select the material and shaft seal for the pump

⑧ Determine the consumption of cooling water (or heating steam)

⑨ Select electric motor

⑩ Determine the standby rate and number of pumps