Spot-welded end fitting for flexible metal piping

Claim 1

A spot-welded flexible metal piping and end fitting assembly, which comprises: (a) a length of flexible metal piping, which includes: (1) a generally continuous, spiral-wound metal band with interlocked leading and trailing edges; (2) a continuous spiral seam between said band edges, said interlocked leading and trailing band edges forming four layers of said band material at said spiral seam; (3) an open end; (4) a bore extending from and open at said end, said bore extending generally axially with respect to said flexible piping; (5) inside and outside diameters; (b) an end fitting including an intersection with a generally cylindrical configuration, a throughbore, an inside diameter, an outside diameter, an inner end adjacent to said inner section, an outer section with an outer end adjacent to said outer section, said inner section and said outer section having substantially equal diameters; (c) said fitting inner section being received in said piping bore; (d) a plurality of resistance spot-welds spaced circumferentially in proximity to said piping open end, each said spot-weld extending through four layers of said band material at said spiral seam and into said fitting section and each said spot-weld being of a width sufficient to bridge said spiral seam and structurally fuse respective band leading and trailing edges and the coupling; and (e) an annular gasket positioned between said piping adjacent to the end thereof and said end fitting section.