Provided are an electric resistance welded stainless clad steel manufactured by forming a hot-rolled steel strip of clad steel including low-carbon low-alloy steel and stainless steel into a cylindrical shape, and electric resistance welding the edges of the hot-rolled steel strip, characterized in that the flattening characteristic of an electric resistance weld, as-welded, satisfies the formula h/D<0.3, wherein h is the flattened height at fracture (mm) and D is the outer diameter of the pipe (mm), and a method of manufacturing the same.

For the determination of the welding current to be used for the resistance welding of the overlap seam of container bodies, welding with a test body is carried out with a changing strength of welding current which in the test body produces a varying welding of the seam. The current strength varies from welding of this seam with a too high temperature to welding with a too low temperature. Along with this the welding current strength used in the welding is determined so that it is further determined at which point of the seam the welding has been accomplished and with what strength of welding current. By means of a mechanical and/or optical investigation of the welded seam it can then be easily determined where the seam has been correctly welded for the series production of container bodies from the same sheet material as the test bodies. When such a point or such a region of the seam is known the welding current used in the test welding can be taken as the welding current for serial production.

An optical cable and method for forming an optical cable is provided. The cable includes a cable jacket including an inner surface defining a channel and an outer surface and also includes a plurality of optical fibers located within the channel. The cable includes a seam within the cable jacket that couples together opposing longitudinal edges of a wrapped thermoplastic sheet which forms the cable jacket and maintains the cable jacket in the wrapped configuration around the plurality of optical fibers. The method includes forming an outer cable jacket by wrapping a sheet of thermoplastic material around a plurality of optical core elements. The method includes melting together portions of thermoplastic material of opposing longitudinal edges of the wrapped sheet such that a seam is formed holding the sheet of thermoplastic material in the wrapped configuration around the core elements.

A method of monitoring a manufacturing status of an electric resistance welded pipe manufactured by shaping a steel strip into a pipe and butt welding both end parts of the steel strip in a width direction along a lengthwise direction includes: arranging an imaging unit in a gas shield nozzle having an opening opposing a region in which both of the end parts of the steel strip in the width direction are butt welded and shielding the region with inert gas by ejecting the inert gas onto the region through the opening, the imaging unit having a visual filed including the region; and determining quality of a butt-welded part based on an image shot by the imaging unit.

Provided is a welding monitoring apparatus that monitors a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured. This welding monitoring apparatus includes an image capturing unit that captures images of a region including the V-convergence region in time series; and an image processing unit that extracts a welding point based on the images captured in time series and detects the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.