We recently published a story on our blog about the myth of ERW tube being in some way weaker than other forms of steel tubing. In it we pointed out that this was based on experiences with the products before the mid 1970s, and did not allow for the enhancements made by the development of new technology and techniques. This article, we are delighted to say, has proved to be rather popular. As a result, we’ve been asked to give some more information on the developments which improved the quality of ERW steel tubes.
The biggest change which served to improve the quality of ERW tube was the one to the welding process. Up until the 1970s the steel tubes were made using a low-frequency electric resistance weld. There were several reasons for this, with the main one arguably being that it was the approach which allowed for smaller diameters to be made. It is also true that the cost factor had a bearing on using this approach rather than a high-frequency resistance weld.
Whilst using low-frequency electric resistance weld made sense, it was the reason why ERW steel tubes came to be seen as weaker than other forms. The lifespan of tubes created this way was shorter, with hook cracks and seam corrosion being two of the most common problems encountered. In some cases the relative low cost of ERW tube was lost as an advantage due to the lack of a reliable lifespan.
It was the development of the means to use high-frequency electric resistance weld on steel for smaller diameters that saw this tubing become far stronger. This resulted in it becoming more reliable for a longer service. As well as making more resilient ERW tube, the high-frequency electric resistance weld process is also more flexible and efficient – allowing for even lower costs to be achieved.
The history of the development of ERW tubes is one we find highly interesting. We’re always happy to answer questions about it, and we trust that you’ve found the information about the production process change in the 1970s to be an informative insight.