Abstract: A method and apparatus for groove weld joining pipe sections along a rotating preform having a circumferential groove thereon along which the preformed adjoining pipe sections are located to form a weld in the joining area and a underbead in the groove of the preform to thus weld together the pipe sections.

Abstract: An apparatus and method for pacing the application of a manual weld along the weld line generates beeps or light flashes at a rate which can be correlated by the welder with markings along the weld line. As each beep or flash is perceived, the welder should reach the next marking. Spacing between the markings determines the desired rate at which the weld is being applied. Alternatively, sequentially lightable areas are distributed along the weld line and sequentially lit a desired rate. The welder chases the sequence along the weld line to achieve the optimum rate of welding.

Abstract: A plasma arc welding process for welding metal of increased thickness with one pass includes operating the plasma arc welding apparatus at a selected plasma gas flow rate, travel speed and arc current, to form a weld having a penetration ratio to weld height to weld width, and maintaining the penetration ratio at less than 0.74. Parameters for the plasma gas flow rate, travel speed and arc current are adjusted to a steady state condition during a start up period and maintained during the steady state condition to complete a weld. During a terminal stopping period, the travel speed is stopped and instantaneously replaced by filler wire which adds material to fill the keyhole that had been formed by the welding process. Parameters are subsequently adjusted during the stopping period to terminate the weld in a sound manner.

Abstract: An improved high energy density welding method for reducing input keyhole welding prepares the weld joint (8) between two edges (10, 14) of at least one member by separating the edges (10, 14) of the member (12, 16) with a controllable gap (22) by a projecting portion (24) selectively positioned on one edge (10, 14) of the member (12, 16). The projecting portion (24) closely abuts the other edge of the member for maintaining the controlled distance (d) of the controllable gap (22) to enhance the welding method.