KSB Launches Revolutionary Imvubu Wastewater Pump

New pump has a big “mouth” and enough power to manage solids.

KSB has officially launched the KSB ELN-150 Imvubu, a rugged new self-priming wastewater pump developed and built in South Africa specifically for African operating conditions.

Named after the Imvubu which is the Zulu word for hippopotamus, then name carries a double meaning referring to its distinctive top-mounted lifting “ears” that mimic its profile in water, while its massive free-pass mouth and formidable strength mirrors the exceptional solids handling ability that swallows-up oversized waste and attests to the toughness and power of its design.
KSB Pumps and Valves product manager for wastewater, Hugo du Plessis, says the KSB Imvubu is the result of years of development which measured the strengths and limitations of earlier self-priming pumps used in municipal wastewater networks across Southern Africa. During this time KSB Pumps and Valves engineering team worked closely with municipalities and industry operators to understand the realities they face daily including clogging, solids carry-over, complex maintenance, pump failures in remote areas and the need for equipment that is easy to service in places where skills are often scarce and uptime is critical to prevent spills.

“We live in South Africa and can see the challenges of dealing with sewerage and waste water. We also listened to the market where customers told us exactly where the problems lie in terms of pump clogging, difficult seal replacement, thin casings that wear quickly and designs that simply do not stand up to raw, unscreened sewage. This culminated in the development of the KSB Imvubu pump which is our answer to the market’s needs. It is proudly designed and manufactured in South Africa and takes the best global technology and optimises it for African conditions,” says du Plessis.

He explains that the KSB Imvubu pump was developed using advanced CFD (Computational Fluid Dynamics) modelling and efficiency redesigns of the impeller, volute and hydraulic passageways. The result is significantly improved pumping performance, now reaching more than 65% hydraulic efficiency which places it well ahead of competitor self-priming pumps currently in service. Critically, the pump achieves a 77.3 mm free-pass solids handling capability exceeding the global raw sewage benchmark of 76 mm. In real-world operation, that 1.3 mm can be the difference between uninterrupted pumping and a costly blockage.

KSB Imvubu pump in final production

“The free pass is what sets us apart. It is market leading and equates to the fact that if a pump can pass a bigger solid it will clog less. It is that simple and less clogging means less callouts, less downtime and less cost.”

In addition, the KSB Imvubu features bearings-for-life with no oil lubrication required. Unlike competing pumps that require oil chambers, top-up checks and contamination risk, the KSB Imvubu pump uses grease-for-life bearings and KSB’s own mechanical seal which is lubricated by the pumped medium itself. This makes the pump environmentally cleaner, safer to maintain and significantly simpler to service. The pump body is also cast with thick, heavy-duty volute walls to resist erosion and extend operating life, while its smart design includes an inspection hatch that allows staff to clear blockages without removing the suction cover which is a major advantage for treatment plant technicians and municipal maintenance teams.
“We know that South Africa’s wastewater infrastructure is under immense strain with limited resources and ever-rising sewage volumes which means equipment must be robust and easy to service to ensure its longevity. These are exactly the issues we have considered and served as guiding principles for our Imvubu pump and our design directly addresses the problems encountered in the field. We have made this pump for Africa and that is why we made it to be maintained using basic tools and why it can be speed-adjusted using simple pulley changes. It can also do the job of two pumps simply by moving from low to high heads and low to high flows easily with no need for a second pump. It can even be mounted on diesel skids for remote pumping or flood emergency use. It is versatile, strong and practical,” says Hugo.
Applications extend beyond municipal wastewater to mining sumps, industrial effluent, pulp and paper, agricultural waste dams, river abstraction and portable dewatering units. The pump has already proven itself during extended testing at the Drakenstein Wastewater Treatment Works in the Western Cape where it has operated continuously with excellent results.
Because the KSB Imvubu pump is 100% locally manufactured, it aligns strongly with the Department of Trade and Industry’s localisation incentives supporting South African industry and local employment. It also positions KSB Pumps and Valves as a major contributor in the export of high value engineered products into Sub-Saharan Africa and other regions where similarly robust and versatile pumps are required.
“This is a pump we are proud to build in South Africa as it keeps our people employed and shows that we can compete and lead international brands. We like to think that we do not follow, we leapfrog. Our Imvubu pump is a direct answer for many of the failures making national headlines and the timing in this period of regeneration could not be more significant. Municipalities and utilities urgently need equipment that can keep working away with minimum attention and maintenance to clear the backlog – and we are proud to say the answer is the KSB Imvubu,” Hugo concludes.