Oversize Diameter Slender Wall Welded Tube

In modern industrial fabrication, the demand for lightweight yet high-capacity conduit systems has driven engineers to specify advanced steel solutions. Our Big Bore Light Wall Carbon Steel Welded Tube portfolio leads this shift, delivering exceptional diameter-to-thickness ratios without sacrificing structural integrity. Customarily referred to as an Oversized Caliber Slim Wall Welded Steel Pipe, each unit is crafted using continuous high-frequency welding and precision sizing to ensure uniform wall reduction across the entire length. For architects and mechanical contractors, our Wide Diameter Low Thickness Carbon Steel Tube series merges expedited flow characteristics with downsized material expenditure, while the Broad Bore Thin Gauge Welded Steel Pipe variant meets stringent ASTM A500 and EN 10219 specifications for hollow structural sections. These products are manufactured under tight ovality controls and eddy-current testing to eliminate surface and subsurface anomalies, guaranteeing performance in pneumatic conveying, agricultural irrigation booms, and lightweight piling applications.

The Oversize Diameter Slender Wall Welded Tube pushes the boundary of achievable D/t ratios, routinely sustaining diameters above 300 mm with wall thicknesses as low as 1.5 mm. This configuration dramatically lowers the weight per linear meter and reduces handling costs during installation. Our proprietary inline annealing process relieves residual stress from the forming and welding stages, resulting in a fine-grained microstructure that improves fatigue resistance under cyclic loading. The tube’s slim wall profile enhances heat transfer efficiency in HVAC condensers and evaporators, while the generous bore size accommodates higher volumetric flow in dust collection and bulk material transport networks. Each production lot is subjected to hydrostatic or pneumatic proof testing and can be supplied with a protective black lacquer, hot-dip galvanized, or raw mill finish depending on the exposure environment.

Key Product Specifications

• Outer Diameter Range: 219.1 mm to 1,020 mm (8.625″ to 40″)
• Wall Thickness Tolerance: ±0.25 mm for walls ≤ 3.0 mm
• Length Options: Standard 6 m or 12 m random; fixed lengths up to 18 m available
• Steel Grades: S355J2H, Gr. C, API 5L X42/X52 PSL1 (Grade B equivalent), dual-certified options
• Welding Method: ERW high-frequency longitudinal seam, fully normalized per ASTM A671
• End Finishes: Plain square cut, beveled to 30°, or grooved for Victaulic couplings
• Surface Condition: As-welded, pickled and oiled, or externally coated with 3LPE anti-corrosion layer