In the 50s and 60s, spiral steel pipe was widely used in oil and gas transmission pipelines. In the 1970s and 1980s, it was seriously challenged by LSAW and ERW steel pipes. Spiral steel pipes are basically no longer used in oil and gas pipeline transportation. Many large oil companies and pipeline companies in the world have not allowed the use of spiral submerged arc welded steel pipes on oil and gas pipelines.
This is because the development of the pipeline industry is increasingly demanding the reliability of steel pipes, and spiral steel pipes are difficult to meet the requirements of objective development due to defects that cannot be overcome by their own manufacturing. There are certain deficiencies in the quality of the spiral pipe and the straight seam submerged arc welded steel pipe. There are seven articles for your reference.
(1) The manufacturing process of spiral steel pipe determines its residual stress. According to foreign data, some even approach the yield limit. The straight seam submerged arc welded steel pipe adopts the pipe expansion process and the residual stress is close to zero. (2) Spiral weld seam tracking and ultrasonic on-line detection and tracking are difficult. Therefore, the probability of weld seam exceeding the standard is higher than that of straight seam submerged arc welded pipe. (3) The amount of misalignment of spiral steel pipe welds is mostly 1.1 to 1.2 mm.
According to international practice, the amount of misalignment is less than 10% of the thickness. If the wall thickness of the pipe is small, the amount of misalignment is difficult to meet the requirements, and the straight seam submerged arc welded pipe No such problem. (4) Compared with the straight seam submerged arc welded pipe, the spiral weld seam is poor in flow line and the stress concentration is serious.
(5) The heat affected zone of the spiral submerged arc welded steel pipe is larger than the heat affected zone of the straight submerged arc welded steel pipe, and the heat influence The area is a weak link in the quality of the welded pipe. (6) The spiral geometry of the spiral seam welded steel pipe is poor, which brings certain difficulties to the on-site construction (such as counterparts and welding). (7) The same diameter, spiral seam welded steel pipe can achieve a much smaller thickness than the straight seam submerged arc welded steel pipe.
For more info, please refer to; https://www.permanentsteel.com/productshow/ssaw-steel-pipe.html or https://www.permanentsteel.com/productshow/lsaw-steel-pipe.html.