Sewage and sewage treatment plant pumps are constantly being exposed to aggressive fluids while in service. Corrosion and abrasion, UV light, heat, cold, salt, condensate and alkalinity are all elements that influence the surfaces and material structures of the units, sometimes with considerable impairment to performance. 

This can significantly reduce the hydraulic efficiency of a pump and not only results in higher energy consumption, but also leads to a greatly reduced service life due to the displacement of the load locus for the motor and hydraulics.

Resisting destructive elements

Wilo Ceram is a sprayable, solvent-free, two-component polymer coating material reinforced with aluminum oxide for corrosion protection against aggressive media that is available exclusively for Wilo submersible pumps and mixers. 

Thanks to its increased resistance to potentially destructive elements, it effectively prevents wear and chemical degradation, ensuring optimal functionality and performance. Wilo pumps and units with Ceram coating are designed to experience less maintenance-related downtime and have a long service life.

A specific case study uses the example of an impeller coated with Ceram versus a standard, uncoated cast iron impeller to illustrate the performance and the associated potential for cost savings. In a processing plant for kaolin — a type of clay — the fluid is so abrasive due to the large amount of small-grain sand that a cast iron impeller, which normally has an operating time of about 100,000 hours with no problems, had to be replaced after just 500 hours’ operation. In a test period of 15 months, a total of four cast iron impellers were replaced.

The replacements resulted in acquisition costs, loss in performance efficiency, increased energy costs and downtime due to removal and installation.

“Comparatively, under the same conditions in exactly the same time period, an impeller coated with Ceram was used,” says a company spokesperson. “After approximately 2,000 hours of operation, the impeller finally needed to be replaced. The coating allowed the impeller to remain in operation four times as long as the uncoated impeller.”

Ceram is used both for the outer coating as well as for the interior coating of Wilo submersible pumps and mixers and is applied using an airless method in one layer with a thickness of 0.4 mm. Wilo Ceram offers all-round protection for all unit components, whether they are inside or on the surface.

Wilo USA is a subsidiary of Wilo SE, which is headquartered in Dortmund, Germany. Wilo is one of the leading manufacturers of pumps and pump systems for heating, cooling and air-conditioning technology for water supply and for sewage and drainage. The company is represented worldwide in over 90 countries by more than 60 subsidiaries, including 21 production sites, and employs more than 7,700 people globally.