FIELD: construction of pipelines of different application. SUBSTANCE: electric welder is mounted on outer side of pipe. When welding end face of first pipe with end face of second pipe, welder is constantly moved along guide. First initial pass is carried out for welding root using electrode wire for forming welding pool between end faces of pipes. To hold end of electrode wire in front of welding pool when carrying out initial pass, speed of welder travel is changed without stopping the welder. Power generator is mounted on welding tractor for setting the latter in operation. Power source is connected with generator. Proposed device has also electric welder with electrode wire feeder, welding head and mechanism to control travel of welder over pipe circumference and devices for connecting welding head with power supply source and device to regulate electric welder travel speed in process of welding when it moves along guide. Power supply source is made to provided surface tension and form small flat weld on outer surface of pipe without use of additional equipment. EFFECT: improved quality of welds. 28 cl, 13 dwg
