Abstract
Pipeline installation requires the use of a welding equipment presenting high pipe-laying efficiency and therefore high welding speed. It has been attempted for this need to develop the latest automatic pipeline welding system. The first report has described the development of welding procedure by the automatic one side downhill welding method using high-current-density GMAW with regard to the girth welding of pipe. This report describes the development of these equipments and controlling system.
Characteristics of this controlling system are summarized as follows.
1) All welding sequences and conditions are controlled by a microcomputer.
2) The position of welding carriage is controlled by ten thousand addresses around a pipe of any diameter.
3) Two welding carriages can detect starting point of arc automatically using the plate with two magnets. and can weld at the same time.
4) Beads of starting position and crater are overlapped automatically welding by Soft-Arc-Start condition, therefore weld is completed with no intergrinding.
