Abstract
Long life and reliability in pumping abrasive slurry are more important than initial cost and efficiency. Here, several wear tests for impeller, reducer and frontliner of unshrouded centrifugal pump were executed at 2 sites of shield tunneling work. The influences of soil and metal including some surface coatings properties on the wear characteristics of pump parts were investigated. As the results, the effects of surface coatings treated on a reducer are displayed remarkably at initial stage of wear. To prevent the eccentric wear at a bottom of reducer or frontliner, it is necessary to increase the flow velocity at the inlet of pump not to occur a state of bed-load slurry movement, or to rotate their setting positions periodically.
