SMAW pipeline welding with downhill progression



Since Pipelines are the best means of transporting fuels and other valuable goods over thousands of miles to meet energy requirements. These long extended pressure pipelines are manufactured from steels and welding is one best suited method to fabricate them. It’s a common and recommended practice to weld pipeline joints with downhill technique, which is performed by two welders at a time from the opposite sides. After joint preparation (beveling), two massive pipe pieces are hold together with the help of clamps as shown in the video and welds are made from top to down ends. 
This is how to weld pipe joint using Shield Metal Arc Welding process which is actually with the downhill progression.

This article discusses some common considerations about;
  • Use of Shield Metal Arc process for Pipeline Welding.
  • Joining Techniques
  • What material and Joint configuration is used?
  • Why Pipeline is being welded by downhill technique?

Use of SMAW process
It’s an exceptional characteristic of cellulosic electrodes that they can be best suited for vertical down position due to rapid slagging process (Also Read 8 exceptional features of cellulosic Electrodes). Organic materials in cellulosic covering produce quick slag that yields good vertical welds and that is why Shield Metal Arc Welding is highly supportive process in pipeline welding.

Clamping of work pieces
No tack welds are used in order to keep the joint gap intact, but the work pieces are hold together by using some sort of clamps. After keeping the joint intact, two way welding progression is started on either sides.

Material and Joint Considerations
Pipelines are normally fabricated from steel pipes. Material selection is based on working and type of media (fuels or goods) to be transported. Rapid welding is observed in joining of pipeline and the reason for that is, because the work pieces are of less thickness and are normally welded with less joint gap. Moreover it is better to say that the joint is filled by two welders and that is why it looks faster than the workshop welds.

Last Words

Using downhill technique, to weld long extended pipelines is one best method that is providing highly productive results in the field of oil and gas fabrication industries.  It’s a bit faster than other welds as the process requires two welders, to weld thinner joint on either sides. 

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