Patent ID: 8350176

Claim:
A method for forming a ribbing in an inner wall of a tubular member comprising the steps of: providing a spindle having a lesser diameter than the internal diameter of the tubular member; compressively wrapping a wire-like member helically along the length of the spindle; applying a metal brazing material onto an exterior surface of the wire-like member; inserting the spindle with the wire-like member wrapped thereon into the interior of the tubular member; releasing the compression on the compressively wrapped wire-like member; withdrawing the spindle from the tubular member thereby leaving the wire-like member in the tubular member such that the wire-like member remains in the tubular member; heating the tubular member thereby melting the metal material to bond the wire-like member to an inner surface of the tubular member; wherein the metal material is BNi-2 nickel-bearing brazing filler paste; wherein the wire-like member has a quadrilateral cross section.