Abstract: A method and a system for forming a root pass weld for a root pipe joint. A substantially periodic electric welding waveform is generated and a series of electric arc pulses are generated between an advancing welding electrode and a root pipe joint in response to the electric welding waveform. The electric welding waveform includes a base cycle having a background current phase providing a background current level, a peak current phase providing a peak current level, a tail-out current phase providing a decreasing tail-out current level, and at least one heat-increasing current pulse during the background current phase providing a heat-increasing current level being above the background current level.

Abstract: A laser sensor to scan the weld joint either before welding begins as a pre-weld scanning operation or in real time during welding to provide adaptive control of the arc welding parameters. A “line” type laser sensor device projects a laser line within a fixed operating window. The line laser produces a reflective position of anything that the laser line “sees” within the operating window. By triangulation, the exact distance an object is from the laser can be measured at any point along the “line” of the laser. Certain parts of the weld bevel are targeted for measurement. The measurements are stored in an electronic storage medium and a data processor. The stored measurements and data processor are used in conjunction with automated welding equipment to adjust the welding parameters as required. Because the exact joint/weld geometry is then known for every portion of the weld, the welding equipment can then respond or “adapt” to variations in the weld joint between the work pieces.

Abstract: A narrow groove GMAW torch for thick section welding that addresses the problems of conventional welding torches. A main body portion has a power block with electrical, feed welding wire, water cooling, and shielding gas connections and a contact tip. A dielectric is attached to the main body portion and has a primary shield gas outlet. A gas shield attached to the dielectric defines an annulus between them that functions as a secondary gas shield. A diffusing gas outlet in the dielectric delivers shielding gas to the weld area. The contact tip attached to the power block is designed to receive and control the curvature of the feed welding wire.

Abstract: A method and a system for forming a root pass weld for a root pipe joint. A substantially periodic electric welding waveform is generated and a series of electric arc pulses are generated between an advancing welding electrode and a root pipe joint in response to the electric welding waveform. The electric welding waveform includes a base cycle having a background current phase providing a background current level, a peak current phase providing a peak current level, a tail-out current phase providing a decreasing tail-out current level, and at least one heat-increasing current pulse during the background current phase providing a heat-increasing current level being above the background current level.