The difference between fixed welds, welds, and prefabricated welds in pipeline welding

In long-distance pipeline transportation projects, pipeline welding is often the most important processing step, so the choice of welding joints and welding methods during processing will become more important. In general welding operations, fixed welding, rotary welding, and prefabricated welding are often selected.

Fixed welding means that the weld joint cannot be moved after the pipe group is paired, and it changes with the welding position during the welding process (horizontal, vertical, elevation, and pitch changes). Welders perform Omni-directional welding, especially when overhead welding, the welding method is not easy to operate, and the welder has high technical requirements and is prone to defects. It is usually constructed on the pipe gallery and gradually replaced by other welding methods.

Rotating weld is the turning weld during the welding process so that the welder can perform welding in an ideal position (horizontal, vertical, elevation, or tilt). The welding position is flat welding or vertical welding. The welding operation is convenient and there are few defects. The construction is basically on the ground or floor. And this is easily affected by the welding site, so this is only used on some specific projects

Under normal circumstances, we use fixed ports as movable ports. The movable port is a pipe prefabricated welding port, and the pipe section can be moved or rotated when the pipe is prefabricated off-site. The fixed port is a welding port installed on-site, and the pipeline cannot be moved or rotated at this time.