Case Studies

Innovative use of ceramic minimizes wear and noise for leading pump manufacturer (27/04/04)

With an annual production of approximately 10 million products a year and manufacturing operations in 12 countries Grundfos is one of the most recognised and respected pump manufacturers in the world. Dedicated to making its products as reliable and durable as possible, Grundfos works with partners, education institutions and suppliers to research and develop the best pump technology for its products. One of the longest relationships of this kind is with Morgan Advanced Ceramics, which supplies the manufacturer with bearings, shafts and washers for its circulator pumps.

Circulator pumps are used in central and district heating systems and domestic service systems. They need to be able to run quietly and consistently for long operational periods - often up to 5,000 hours a year. As part of its on-going work to improve its products, Grundfos realised that the traditional steel-shaft carbon bearings used in the pump were having a direct impact on the pump's longevity and noise. 

"Bearings are critical to the pump's performance and in order for us to offer products with a maintenance-free15 year lifetime we needed to find a material that could rotate within the water - which contains abrasive wear particles created by corrosion in the heating plant - without excessive wear," explains Preben Jakobsen, Technical Manager, Grundfos. "By using ceramic, we know there will be no increased bearing clearance and therefore no noise increase over time and that the pump will meet and exceed its lifetime expectations."

Other bearings are made of steel-carbon. This material combination does not offer abrasive wear resistance to the most common abrasive wear particle - black iron oxide - which is present in heating plants containing mild steel parts. These bearings become increasingly worn resulting in increased noise levels and in some cases, maintenance requirements.

During its research into alternative materials, Grundfos became aware of Morgan Advanced Ceramics and its technical ceramics capability. The companies began working together to establish which material would be best suited to the application and the result is the inclusion of Morgan Advanced Ceramics' HiloxTM alumina bearings within the pump.

Jakobsen comments, "Morgan Advanced Ceramics' knowledge of materials was impressive - and played an important part in our design process. As a result of their efforts to help us identify the best solution we have had a long and successful relationship."

HiloxTM alumina used in the bearings is Hilox 961 (96% alumina) - this was chosen because of its near-diamond hardness which makes it extremely resistant against abrasive wear. Unlike carbon-steel, the material shows no wear during the pump's lifetime and no noise increase occurs. 

Another key factor in the partnership was Morgan Advanced Ceramics' ability to produce large quantities of consistent and high quality end product. 

"To supply large global companies such as Grundfos we have to have the facilities and expertise to provide them with the quantities they need," explains Chris Paine, Sales and Application Engineer at Morgan Advanced Ceramics. "By operating in these volumes it also enables us to offer competitive prices - which is essential in today's economy. Morgan Advanced Ceramics is continuing to invest and optimise its processing facilities to keep in line with the forecasted year on year increased demand for Grundfos and its customers."

Morgan Advanced Ceramics also supplies bearings and washers for other Grundfos products including its submersible, centrifugal and composite pumps and is working with Grundfos on more diverse and innovative pump technologies such as dosing pumps.