Welding tubes to tube plates - using disposable support ring to protect lining in bore of tube from weld metal.

摘要

Process for welding tubes into tube plates, the novelty being that during welding, the seam is shielded from the bore of the tube by a metal support ring located in the tube outside the zone of the weld and pref. 5mm. below the end of the tube mating with the tube plate; and after welding, the support ring is at least partly bored out. Boring out pref. occurs in two stages, (a) removing the inner portion of the support ring; and (b) removing the outer part of the support ring in contact with the bore of the tube. The support ring pref. consists of a short length of outer tube tack welded to a concentric, longer inner tube leaving an annular gap. Used e.g. in the welding of composite tubes in a tube plate for mfg. cracked gas coolers. The bore of the tube is protected from weld spray.