Welding Methods and Selection in Long-distance Pipeline

The features of manual downhill welding, semiautomatic welding, automatic welding and other welding technologies like butt flash welding and laser beam welding (LEW) and so on are analyzed.The author considers that the pipe diameter, wall thickness, length of pipeline, design requirements and steel grade of pipe should be taken into account when welding methods are selected, and points out that the automatic welding technology is available in long-distance pipeline with high productivity and quality.Some problems to be paid attention to on the welding equipments imported are put forward.