| 摘要 |
A centralizer for installing on a metal pipe. The centralizer includes a generally tubular body having a central opening sufficiently large to allow insertion therethrough of a pipe having an external diameter; a sidewall of substantially uniform thickness including an inner-facing surface directed to the central opening and an outer-facing surface onto which are formed a plurality of outwardly protruding ribs by hydroforming the sidewall. A method for hydroforming a centralizer including placing a length of metal tubular work piece, the work piece having a sidewall and an central opening, inside a confining surface comprised of mold elements, the mold elements including cavities spaced and shaped in the configuration of desired side wall centralizer ribs, the mold elements being supported substantially against expansion radially outward from their position about the tubular work piece; applying sufficient pressure to the side wall through the inner bore to force the tubular sidewall radially outward against the confining surface and into the mold cavities to plastically deform the side wall to form centralizer ribs on the side wall; and removing the tubular work piece from the confining surface.
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