7305.11 - Longitudinally submerged arc welded:

This HTS category, 7305.11, specifically covers pipes and tubes of iron or steel that are longitudinally submerged arc welded and intended for use as line pipe in oil or gas pipelines. The defining characteristic of this subcategory is the submerged arc welding method employed for their longitudinal seam. These pipes typically have a circular cross-section and an external diameter exceeding 406.4 mm, as per the parent category.

It is important to distinguish this category from its siblings. While 7305.12 also covers longitudinally welded pipes, it encompasses other welding methods besides submerged arc welding. Similarly, 7305.19 covers "other" tubes and pipes within the broader scope of 7305, which may not be line pipe for oil or gas, or may employ different construction or welding techniques. Therefore, 7305.11 is a precise classification for a specific type of large-diameter, longitudinally submerged arc welded line pipe.

The subcategories within 7305.11 further refine the classification based on the material composition of the pipe. Subcategory 7305.11.10 applies to pipes made of iron or nonalloy steel, which are common materials for such pipelines. In contrast, 7305.11.50.00 is reserved for pipes manufactured from alloy steel, which may be chosen for specialized applications requiring enhanced properties like corrosion resistance or higher strength. This distinction is crucial for determining applicable duties and trade regulations.