Giving pumps a new lease of life

Retrofitting is an excellent alternative to buying a new product and can be performed on pumps regardless of their intended use.


Local pump manufacturer, KSB Pumps and Valves is leading the way with its wide range of service that assist users to get the most out of their pumps when pumping requirements change or to prolong the life of existing g pumps.

According to the company’s regional sales manager for Sub-Saharan Africa, David Jones, retrofitting is equally suitable for industrial, water supply and waste water disposal applications as well as for the power supply industry. The advantages of a retrofit solution are the combination of state-of-the-art technology and expert service.

Changing requirements

“Changed circumstances often require a new approach. This also applies to pumps which are used in fluid transfer systems where increased energy efficiency is required, to meet new legal requirements, to extend the service life or adapt technology to new operating data, as this does not always necessitate a new pump.

“The areas of use for retrofit solutions are as diverse as the requirements to be met by the pump systems in question. As a result, retrofit solutions go together with hydraulic and mechanical modifications as well as with changes to the materials.  

“There are a number of benefits that can be applied to lower maintenance costs, reduce power consumption, achieve longer service life, increase system availability or even to comply with legal requirements (e.g. TA-Luft, ATEX),” says David.

Optimised systems

Good can be made even better by optimising pump systems with retrofits. Below are some examples of what can be done:

Hydraulic modifications:

  • Re-machining of existing impellers
  • Installation of new impellers for off-design conditions
  • Reduction of NPSH-required value through the installation of an inducer or suction impeller
  • Optimisation of volute casing for off-design conditions
  • Adjustment of the number of stages (on multistage pumps)

Mechanical adjustments

  • Closed bearing brackets improve the smoothness of operation and extend the bearing life
  • Installation of mechanical seal systems
  • Employment of cellular surface wear rings to improve efficiency, rotor dynamics and dry running properties

Use of optimised material

  • Super duplex stainless steel grades or nickel alloys
  • Ceramic mineral castings for impellers, wear plates, cover and casing – for use with finely dispersed, highly abrasive solutions
  • Non-metallic rings and bushes
  • Ceramic plain bearings
  • Surface coatings 

Practical example

David explains that practical examples exist locally and abroad throughout the company’s global footprint. In some cases, simple modifications installed in residential pump stations located in residential areas have greatly reduce noise emissions.

In others, retrofits because of changing materials or chemicals can solve premature wear or chemical corrosion, while pumps in power stations may be critical and require retrofits to prolong their lives without the need to manufacture purpose-built pumps with potentially long lead times. With expertise to retrofit almost any pump, specify, manufacture and optimise designs, materials, impellers, diffusers etc, and carry-out hydraulic performance tests, it makes sense to consider retrofitting rather than replacing pumps.

 “We suggest that engineers, contractors and users always weigh-up the benefits of retrofits in collaboration with us. As an OEM manufacturer we will be able to give them real expert advice and provide services in accordance to global standards requirements,” he concludes.

KSB Pumps and Valves, Annett Kriel, Tel: (011) 876 5600, Fax: (011) 822 1746,

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Issue 39