Deformation on Long Tubes? — One-Step 18-Meter H Fin Tube Welding Ensures Precision

In large-scale heat exchangers and high-pressure boiler systems, the dimensional stability of finned tubes directly determines the reliability and efficiency of heat transfer. Conventional multi-section welding or assembly methods often lead to tube deformation, misalignment, or thermal stress distortion during processing. These issues not only complicate installation but also affect the uniformity of gas flow and long-term sealing performance in the system. To solve these challenges, Zhongyue Metallurgy has developed an advanced one-step continuous welding technology for H-type finned tubes, capable of producing tubes up to 18 meters long with exceptional precision and straightness.

The process begins with high-quality base tubes made of carbon steel, alloy steel, or stainless steel such as A179, 20G, or 12Cr1MoVG. Using six automatic H-Fin welding machines, Zhongyue performs continuous fin welding without intermediate joints. Each H-type fin, typically 1.5–3.5 mm thick, is precisely positioned and welded along the entire tube length using full-penetration seam welding. This ensures a consistent mechanical bond and eliminates weak points or weld overlaps that could cause deformation during heating or operation. The resulting tubes maintain straightness within ±1 mm over 18 meters, far exceeding the accuracy of conventional segmented fabrication.

Additionally, Zhongyue’s system can integrate wheel-type or perforated L fins where design flexibility or airflow optimization is required. The combination of H and L fin configurations enhances the mechanical rigidity of the tube body, providing additional structural support against bending or vibration. Each tube undergoes hydrostatic and pneumatic pressure tests, as well as eddy current inspection, ensuring weld integrity and mechanical strength before delivery.

To protect the surface from corrosion and oxidation, all tubes are coated externally with red oxide zinc phosphate primer and internally treated with volatile corrosion inhibitor (VCI). Tube ends are square-cut, deburred, air-cleaned, and varnished for long-term storage stability.

This one-step H Fin Tube welding solution has proven especially valuable in power plant economizers, marine boilers, and waste heat recovery systems, where long tubes reduce joint counts and minimize leakage risks. By ensuring precise alignment, superior bonding, and long-length integrity, Zhongyue’s 18-meter welded fin tubes help clients achieve higher production efficiency, simplified installation, and long-lasting performance under the most demanding industrial conditions.