Abstract
<jats:title>Abstract</jats:title> <jats:p>The Bureau of Reclamation has encountered challenges with coatings on pump casings. The casings are exposed to aggressive erosion conditions due to the suspended solids such as sand and debris in the water. The original pump coatings were fusion bonded nylon which had excellent abrasion resistance. The pumps showed no damage after the initial testing. In 2010, the pumps were inspected, and the coating was eroded away on portions of the pump casing. Bare metal was exposed and corrosion was present. The pump coatings had failed after 5000 hours of operation. High velocity impingement erodes away the coating, reducing material thickness, and eventually causing premature failure. Therefore, the ideal coating for pump casings is highly erosion-resistant in addition to having superior corrosion resistance and adhesion.</jats:p> <jats:p>Presently, there is not an appropriate ASTM Standard for measuring the erosion resistance of a coating in immersion. It has been suggested that abrasion resistance is a similar property. However, the damage observed on the pump casings at the Durango Pumping Plant was a result of erosion caused by a slurry of hard particles in water. It is now apparent that the abrasion resistance does not adequately predict erosion resistance for a coating. A laboratory erosion test method was developed to investigate coating erosion resistance. Laboratory test results were compared with field results to determine whether a correlation exists.</jats:p>