7309.00.00 - Reservoirs, tanks, vats and similar containers for any material (other than compressed or liquefied gas), of iron or steel, of a capacity exceeding 300 liters, whether or not lined or heat insulated, but not fitted with mechanical or thermal equipment

This HTS category, 7309.00.00, encompasses large reservoirs, tanks, vats, and similar containers constructed from iron or steel. These containers are specifically designed for holding various materials, excluding compressed or liquefied gases. A key defining characteristic is their capacity, which must exceed 300 liters. The classification applies regardless of whether the containers are lined (e.g., with enamel or plastic) or possess heat insulation features, provided they are not fitted with any mechanical or thermal operational equipment.

When classifying under Section XV, "Base Metals and Articles of Base Metal," and specifically within Chapter 73, "Articles of iron or steel," it is crucial to differentiate this category from others. Unlike categories for finished mechanical or thermal equipment, the focus here is solely on the container itself. Furthermore, the material composition (iron or steel) and significant capacity (over 300 liters) are primary differentiating factors from smaller storage vessels or containers made from other base metals or materials.

Within this broad category, further distinctions are made to refine classification. The subcategories 7309.00.00.30 and 7309.00.00.90 serve to group these large iron or steel containers. While the official HTS descriptions for these subheadings are typically brief, the primary intention is often to differentiate between general-purpose "Tanks" and "Other" similar containers that may have more specialized forms or intended uses but still meet the core criteria of the parent heading. This allows for more granular tracking and reporting of specific types of large iron and steel storage vessels.