The anti-slurry erosion properties of polyethylene for sewerage pipe use

Sewerage systems are more common in Japan. The pipes and fittings in the systems are exposed not only to a corrosive environment, but also to the impact by solid particles contained in mud drains, resulting in an erosive wear on the surface. A strategy for coping with these problems involves replacing the more traditionally used iron and steel pipes with polymeric materials, which have excellent anti-corrosion properties. In this study, a slurry erosion test were carried out using a jet-in-slit apparatus on seven types of polyethylenes, three other types of polymers, and two types of iron and steels, thoroughly taking into account the fact that erosion damage is highly dependent on the impact angle of the particles. As a result, all the polyethylenes proved to have excellent anti-erosion properties, compared with the other materials over the entire range of particle impact angle. Further, a model was proposed to account the impact angle dependency of the erosion damage. The model aided in clarifying the reasons why the erosion rate of the polyethylenes is satisfactorily correlated with a complex parameter in which the fracture energy and the elastic modulus are combined.