Patent ID: 8864012

Claim:
A method of welding two pipes together comprising the steps of: arranging two pipes end to end, the pipes being so shaped that a circumferentially extending groove is defined between the ends of the pipes; providing a plurality of welding torches for welding in the groove, each of the plurality of welding torches being independently movable, relative to the other welding torches, circumferentially about the groove in the same direction; using at least some of the plurality of welding torches to perform a first welding pass, adjusting the welding characteristics of the plurality of welding torches, and using at least some of the plurality of welding torches to perform a second welding pass, wherein at least one torch welds in a first sector in the first welding pass and a second sector in a second welding pass, the second sector being different from the first, wherein a plurality of welding passes of a section are performed in the same direction without any welding torches being required to return to a previously welded sector of the pipe, and previously dormant welding torches joining the welding process and previously active welding torches leaving the welding process and becoming dormant, such that, during at least part of the welding process the active welding torches are sandwiched between dormant torches.