is initially received from conventional conveyor equipment vertically adjustable supports 14 are each elevated by column 15 which may hydraulically be actuated by conventional means rolls 16 transverse to rolls 12 are provided at opposite ends of the machine for raising and lowering pipe w and to properly position it for welding the axes of rolls 16 being in the same plane as pipe w are also used to adjust the weld seam location by rotation if the weld seam is not squarely in the 12 o 39 clock position in addition to the above described hour glass delivery rolls 12 and elevating rolls 16 the principal parts of a typical outside welding machine and weld seam guide system 10 comprise stationary vertical support columns 30 at each end of the machine horizontal cross beam 40 supported on vertical columns 30 the adjustable scanning and tracking assemblies 20 mounted on horizontal cross beam 40 and the welding unit 77 with the accompanying moving platform or cart 70 each scanning and tracking beam assembly 20 is of similar construction and design and comprise adjustable optical scanning units which are spaced at measured distances along the length of the horizontal cross beam 40.