Method for constructing an impeller assembly and shaft having interference fit

A method of connecting a shaft and at least a first and second impeller assembly, each of which are coated with a coating of corrosion resistant material throughout their entire exposed surfaces, through an interference fitted connection between coatings comprising providing a first region at one end of said shaft and at least a second region along said shaft, spaced from said first region, said first region of said shaft extending from said one end and both regions formed by a constant tapered surface, providing a tapered surface along a bore of a hub member of each impeller assembly which is complementary to at least a portion of the length of respective surfaces within said regions along said shaft, locating said tapered surfaces along a common axis, inserting said shaft end into said bore of a second impeller assembly, moving said shaft and impeller assembly in relative movement under an applied force, to locate said second impeller assembly in interference fitted connection within said second region and, then, inserting said shaft into said bore of said first impeller assembly and moving said shaft and impeller assembly in relative movement, also under an applied force, to locate said first impeller assembly in interference fitted connection within said first region.