Automatic welding of pipeline in Japan: Part 2—The development of a method for the branch pipe joint in ship pipeline

Abstract

The pipelines used in a ship amount to tens of thousands of metres per ship, and so automatic welding of the pipelines has been widely applied from the viewpoint of saving labour. In most cases the automatic welding process has been used for the welding of butt-joints which can be applied to the pipes in rotary motion, and it has also been used for fillet-welding of the connection between flange and piping. In the butt-welding of fixed pipings, automatic welding processes are now being partly used for position welding but up to the present time automatic welding has seldom been applied to the various types of branch pipe joints in which the welded lines form three-dimensional curves. In recent years, great progress has been made in the technique of constructing steel pipe structures and in the development of practical gas cutting processes to prepare the curves needed for the various welded joints used in piping. This paper deals with various conditions and performance requirements needed for automatic welding, such as the selection of shapes of prepared edges of pipings to be welded, the control of welding positions, the control of welding torches in operation, and the solution and control of other production variables.