GB1298951A - The butt welding of tubes - Google Patents

Abstract

1298951 Welding by fusion FOSTER WHEELER JOHN BROWN BOILERS Ltd 19 Feb 1970 [20 Feb 1969] 9324/69 Heading B3R In non-consumable electrode arc-welding of tubes to tubes or, directly or via stubs, tube plates or headers, using a filler wire 14 in register with the butted parts, a heat-resisting shoe or, preferably, roller 20 is brought to bear resiliently against the filler wire closely (1-20, preferably 10 mm.) in front of the fusion point so as to hold the wire in place. The shoe or roller may be of chromium steel or a refractory material, e.g. ceramic or alumina, and may be cooled, e.g. by water. In application to internal and external tube butt-welding the filler wire may be, as shown in Fig. 1, in two semicircular parts. The butted tubes may, as shown, have a weld preparation groove 24, or be plain or at most have a slight taper in which case the roller is of double frusto-conical shape (Fig. 5, not shown) to position the wire. The filler wire composition is such as to avoid brittle fracture and is preferably annealed before use. The filler wire may be of any crosssection, e.g. circular. A pass using the filler wire may follow a rotor-weld pass.