Within the under-50-liter group, heading 7310 distinguishes cans designed to be closed by soldering or crimping (731021) from other containers (731029). This distinction reflects the intended sealing technology and affects the applicable tariff rate, so importers should confirm the closure design specified in the product documentation.

Heading 7309 applies to containers of a capacity of more than 300 liters, while heading 7310 covers those of not over 300 liters. A container with a nominal capacity of exactly 300 liters therefore falls under 7310. Importers should use the actual rated capacity of the vessel, not a rounded figure, to determine the correct heading.