Coatings can restore pump performance to “better than new.”
Click here to enlarge imageThis occurs as a result of erosion/corrosion and abrasion of the metallic components. Based on studies conducted in Europe, a typical water pump will lose between 10 to 15 points of efficiency over a 10 year period. The amount of wear, corrosion and subsequent degradation of the pump’s performance will be further accelerated if the pump is handling a fluid with solids/slurries, higher fluid temperatures or that is more corrosive than water.
The erosion/corrosion process is experienced by all metal components, including stainless steel because all metals form an oxide layer that is weakly bonded to the surface of the bulk metal. In the continual flow experienced in a pump, this oxide layer is constantly washed and worn away.
Just like human skin, the oxide layer regenerates so the process continues until bulk material is lost resulting in a change of dimensional tolerances as well as an increase in surface roughness. Therefore, replacing worn components with new metallic components will only provide short term improvement as the new metallic components will experience the same erosion/corrosion process.
The effects of erosion/corrosion is more pronounced in lower specific speed pumps where the developed head is higher and there are abrupt changes in flow direction through the wet-end.
As this process continues, the pump’s performance will begin to be effected. The amount of head and flow produced will decrease along with a corresponding loss in efficiency resulting in greater energy consumption per unit volume of flow.
Studies conducted as part of the European Union’s Motor Challenge program have shown that a majority of this performance degradation occurs in the first five to 10 years of pump operation. If unchecked, the degradation will continue until significant loss in performance results in total failure of the pump.
Pump Coatings
Reinforced composite coatings can reduce or eliminate this loss in performance by interrupting the erosion/corrosion process. This occurs because the polymer does not form an oxide layer like metal. As well, depending on the amount and type(s) of reinforcements used within the coating system, abrasive wear can be significantly reduced extending the overall wear life of the pump.