7311.00.00.30 - Seamless steel containers not overwrapped, marked DOT 3A, 3AX, 3AA, 3AAX, 3B, 3E, 3HT, 3T or DOT-E followed by a specific exemption number

This HTS classification covers seamless steel containers specifically designed for the storage and transport of compressed or liquefied gases. The defining characteristic of goods within this category is their compliance with stringent safety regulations, as evidenced by markings indicating adherence to sections 178.36 through 178.68 of title 49 CFR, or by a specific exemption number (DOT-E) granted under those requirements. These containers are typically robust and built to withstand high pressures, ensuring the safe containment of various gases.

The distinction between this classification (7311.00.00.30) and its sibling category (7311.00.00.60, "Other") lies precisely in the required safety certifications and markings. While both pertain to steel containers for compressed or liquefied gases, this specific code applies *only* to those containers that bear the explicit DOT 3A, 3AX, 3AA, 3AAX, 3B, 3E, 3HT, 3T, or DOT-E followed by an exemption number. Containers that do not possess these specific markings, even if they are seamless steel and intended for gas storage, would fall under the "Other" category.

As this is a leaf node within the HTS structure, there are no further subcategories to introduce. Classification within this code is determined solely by the presence of the specified DOT markings demonstrating compliance with safety standards for compressed gas cylinders. Importers and exporters should carefully verify the physical markings on these steel containers to ensure correct tariff classification.