Benefits of Pumping In Series with Centrifugal Pumps

What do you do when the required head for a system is beyond the capabilities of just one standard pump? You could replace the pump with a much bigger, heavy duty pump. But that comes with a lot of additional cost. Perhaps adding another pump in a series configuration will get you the performance you need. In this post, we’ll discuss the advantages of series pumping.

What Does Series Pumping Mean?

According to Gorman-Rupp, “series pumping is a pump configuration used to overcome a high static discharge head or extremely long piping lengths with high friction losses.”

When centrifugal pumps are connected in a line, head increases from one pump to the next, increasing fluid pressure as well. A multi-stage pump, like a vertical turbine, does essentially the same thing.

When two of the same pumps are in series, the combined performance curve will have double the head of a single pump for the given flow rate.

Advantages of Series Pumping

1. Series connected pumps generally require less horsepower than one large pump meeting the same condition point.
2. In most cases, a higher efficiency point is achieved.
3. Centrifugal pumps in series allows for operation at lower speeds. This, in and of itself, has additional ancillary benefits:
   • Reduced wear
   • Lower energy consumption
   • Increased reliability and longer life
4. Pumps are smaller, easier to maintain, and more manageable, versus a larger centrifugal pump.

Disadvantages of Series Pumping

Of course there are some disadvantages to series pumping. More equipment is required for sure. You’ll need more pumps, motors, motor starters, circuit breakers, and drives. You also need to be careful not to exceed the maximum working pressure of the pumps, especially the ones further down the line in series.  This over-pressurization could damage the pump assembly or adjacent equipment.  All that additional equipment is going to take up more floor space as well, but given the advantages above, it’s likely the pluses will offset the minuses.

If you have pumps that are struggling to meet high head requirements, adding an additional pump might be right for you. Be sure to consult an engineer before doing so however. It’s important that the pressure generated won’t damage downstream pumps!

Need help generating more head, flow or pressure in your application? Ask us about it!We gladly provide technical assistance to businesses and municipalities in Wisconsin and Upper Michigan.