No blockages with Grundfos S-tube® impeller



One of the biggest challenges facing the wastewater industry in recent years has been for water utility companies to decide whether to select a pump that delivered energy efficient performance or free passage. Today the Grundfos S-tube® - that is based on completely new technology - offers just such a solution as this S-tube® impeller ensures there are no dead zones and no cutting or moving parts that can get worn out over time

The situation
This was just the situation that a water utility company in the south west of UK found themselves in at a wastewater pumping station that was suffering from high operating costs and many disruptions because of blockages. This situation resulted in reactive call outs which needed to be followed up by vacuum tankering. These incidents were caused by a very raggy influent and resulted in 15 blockages over a three month period and 3 vacuum tanker cleaning events over the same period to remove rags and clean the pump chamber.

The solution
Grundfos were asked to look at the pump station and selected the SL1.80.80 Atex rated S-tube® wet well submersible pump to trial and improve the performance of the pump station. This pump had a solids handling capacity of 80mm whilst maintaining an efficiency of 63% therefore there was no compromise between pump efficiency and solids handling capacity – a key feature of the S-tube® impeller.

The outcome
The introduction of the Grundfos S-tube® impeller pump brought about major reduction in operating costs and disruption as blockages were reduced from 15 over three months to zero; there was no further need to use the vacuum tanker to empty and clean the chamber; reactive call outs were reduced from 31 to 8 over the period of the trial . The client has now installed the Grundfos pumps as a permanent solution and this has brought about operational savings of over £5000 in just the initial three month period of the trial. A true win/win situation.


High operating costs and many disruptions because of blockages was reduced by the Grundfos S-tube® impeller


South west part of UK


South west based water utility company in the UK

S-tube® impeller
The S-tube® impeller offers greater hydraulic efficiency than any other type of wastewater impeller, without compromising free passage. This results in the lowest life cycle cost, trouble free operation and best-in-class non clogging capabilities.


If you need a similar solution, please contact us for further information.


If you need a similar solution, please contact us for further information.