Abstract: The invention is an apparatus and method for Orbital welding of pipes or pipe segments together to form a pipeline, i.e., Orbital welding. A scanner welding unit, a control unit and a welding unit are combined to travel along and above a seam, which is formed between two interfacing base/cylindrical surfaces of every two pipe or pipe segments, scan the pipes/pipe segments relative positioning, alignment and levelling, and their surface geometry and topography and overlay a welding material starting from the root layer at the bottom of the seam and up to its edge and sealing it with a capping layer. The welding unit lowers a welding tip into the seam that may rotate on its axis at different angels relative to the surface during welding. The scanner unit may alert on mismatches on the relative position of the pipes/pipe segments before or after welding and in some cases enable repositioning for a more hermetically sealed weld.