How To Calculate Dewatering Pump Capacity


It's important to understand how to calculate dewatering pump capacity and how this figure applies to your operations before selecting a dewatering pump. Choosing the right pump is the foundation for a successful and efficient dewatering project.


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What Key Data Is Required?

In order to accurately calculate and understand dewatering pump discharge capacity, four key data points are required:

  • Head, which refers to the vertical height difference between water surface levels (e.g. from the lagoon surface to the wash-plant input level)
  • Flow, which is calculated as the length of time it takes to move a particular volume of water, usually measured by either litres per minute or metres cubed per hour.
  • Friction loss, or the additional effort required by the pump as a result of friction in pipework, bends, and changes in the diameter of the pipe.
  • Terminal pressure, which is relevant when water is used to feed a wash-plant because pressure is required at the end of the pipe.

How To Calculate Dewatering Pump Capacity

Engineers have used a number of ways to calculate some of these data points over the years. The traditional method, known as the 'drop test method' of calculating flow, simply meant holding an empty bucket under the outlet and recording how long it takes to fill up. These methods are crude and inaccurate, and today we can calculate flow and head automatically using sensors.

How To Read A Pump Curve

Once the final figures for flow and head have been determined, these numbers can be plotted onto a graph known as a pump curve. It's important to understand how to read a pump curve when you are selecting a pump for your operation. A pump curve is effectively a graphical representation of the performance of a particular pump, and when selecting a pump, it's important to consider your pumping requirements and choose a pump which offers the best performance at the flow and operating head you wish to work at.

How Atlantic Pumps Can Help

Luckily, these days most of the hard work is done for you. At Atlantic Pumps, every pump we sell comes with a data sheet that includes everything you need to know for your dewatering pump capacity calculation, such as a maximum head and flow and an accurate pump curve.

We also pride ourselves on our sustainable working practices and reduced energy usage in the pumps we supply. With Atlantic Pumps, you can rely on our experienced pump professionals to help you to select the right pump for your dewatering project.