Can stainless steel welded pipes be made into thick-walled pipes?

Many people mistakenly believe that stainless steel welded pipes are synonymous with thin-walled pipes, assuming that their wall thickness is greatly limited and that thick pipes cannot be produced. This misconception primarily arises from the longstanding emphasis on the ease and cost-effectiveness of manufacturing thin-walled stainless steel welded pipes compared to seamless pipes under the same compressive strength. However, with advancements in technology, stainless steel welded pipes have overcome this limitation, and thick-walled stainless steel welded pipes are now widely used across various industries.

The Extensive Applications of Thick-Walled Stainless Steel Welded Pipes

In the petrochemical sector, many chemical plants require pipelines capable of transporting highly corrosive substances. Thick-walled stainless steel welded pipes, with their superior corrosion resistance and high strength, ensure the safe and stable operation of these pipelines under complex working conditions, maintaining continuous production.

Similarly, in the oil and gas industry, pipelines must withstand extreme pressure, corrosion, and formation stress. Thick-walled stainless steel welded pipes are well-suited for such applications, significantly reducing the risk of leakage and ensuring operational safety.

The boiler manufacturing industry is another area where these pipes play a crucial role. Whether for industrial or power station boilers, thick-walled stainless steel welded pipes are essential components in the construction of superheaters and reheaters. Their ability to withstand high temperatures and pressures ensures the efficient and safe operation of boilers.

Understanding the Dimensions of Thick-Walled Stainless Steel Welded Pipes

Determining whether a stainless steel welded pipe qualifies as a thick-walled pipe requires more than just considering its wall thickness; the pipe diameter must also be taken into account. In practical applications, stainless steel fluid pipes with a thickness ranging from 3.0mm to 10.0mm are commonly used. Industries such as chemical processing, oil and gas, and boiler manufacturing frequently employ pipes within this range.

For instance, if the pipe diameter is 20mm, a wall thickness of 3mm is considered thick-walled. However, for a pipe with a diameter of 200mm, even a 10mm wall thickness may not be classified as thick. Thus, the classification of thick-walled pipes is relative and must be determined based on diameter and specific application requirements.

The Production Process of Thick-Walled Stainless Steel Welded Pipes

The manufacturing of thick-walled stainless steel welded pipes involves a complex and precise process. It typically begins with uncoiling and flattening stainless steel plates or strips to ensure a smooth surface, providing a strong foundation for subsequent processing. The material is then cut and welded to the required lengths. To maintain production continuity, a loop storage system is often used.

The next step involves gradually bending the material into a tube shape using specialized molds. This process requires stringent control to achieve the desired tube diameter and roundness. The welding process follows, with common techniques including argon arc welding, high-frequency welding, and plasma welding.

After welding, both internal and external weld beads must be removed. Additional processes such as pre-calibration, induction heat treatment, sizing, and straightening ensure that the pipes meet industry standards. Finally, rigorous quality control measures, including eddy current testing and hydrostatic pressure testing, are carried out to verify the integrity and performance of the finished product.

Conclusion

As technology continues to advance, the production of thick-walled stainless steel welded pipes will see further improvements in both performance and cost-efficiency. Innovations in materials and manufacturing processes will expand their applications, making them an indispensable component in various industries. Looking ahead, stainless steel welded pipes will achieve even greater breakthroughs in thick-walled pipe production, contributing to more demanding and specialized fields.