JPS6434514A - Manufacture of wear resistant bent duplex pipe - Google Patents

Abstract

PURPOSE:To improve working efficiency and to reduce manufacturing cost by disposing wear resistant pieces on a recessed part of outside a bent pipe to form an inner pipe, then by joining the outer pipe and the bent inner pipe. CONSTITUTION:The recessed part 5 is provided on the outer surface of the bent pipe 3 and the pieces 4 of the wear resistant material are bonded on its surface by bonding agent. At this time, the outer diameter of the bent inner pipe 2 to be formed is nearly approximated to the bent outer pipe 1. A heating system 6 and cooling water injecting means 7, 7 are set up on the outer periphery of the outer bent pipe 1, and the inner pipe 2 is inserted into the outer pipe 1 and moved. In this way, the outer pipe 1 and the inner pipe 2 are joined through compressive force, a microelastic deformation of the thin part of the recessed part 5 prevents displacement and breaking of the pieces 4. Therefore, as the working efficiency of the duplex pipe is improved and the amount to be used of the pieces 4 of the resistant material is cut down, the manufacturing cost is reduced.