7307.21 - Flanges:

This HTS category, 7307.21, specifically addresses flanges made from stainless steel, which are essential components used for connecting pipes, valves, pumps, and other equipment to form a piping system. These fittings are designed to provide a secure and leak-proof joint, typically by bolting two flanges together with a gasket in between. The material composition of stainless steel provides excellent corrosion resistance and durability, making these flanges suitable for a wide range of industrial applications, including those involving aggressive chemicals or high temperatures.

Distinguishing 7307.21 from its sibling categories at this level, 7307.22 covers threaded elbows, bends, and sleeves of stainless steel, focusing on fittings with integral threaded connections. Similarly, 7307.23.00 pertains to butt welding fittings, which are joined by welding directly to the pipe. Category 7307.29.00 encompasses "other" stainless steel tube or pipe fittings not otherwise specified. Therefore, 7307.21 specifically isolates the flange type of fitting within the broader context of stainless steel pipe connection components.

Within HTS 7307.21, further subdivisions exist to refine the classification based on the manufacturing process. Subcategory 7307.21.10.00 covers flanges that have undergone minimal post-forging processing, meaning they are either left in their forged state or have undergone very basic finishing. In contrast, 7307.21.50.00 accounts for all other stainless steel flanges that have been machined, tooled, or otherwise processed beyond the scope of the preceding subcategory. This distinction is crucial for accurate duty assessment and trade statistics.