7307.91 - Flanges:

This HTS category, 7307.91, specifically covers flanges made of iron or steel that are not threaded or designed for butt welding. Flanges in this classification are typically used to connect pipes, valves, pumps, and other equipment to form a piping system. They serve as a vital component in the assembly and maintenance of pipelines across various industries, including oil and gas, chemical processing, and water management. The defining characteristic is their function as connection points, facilitating the secure joining of pipe sections or equipment.

Distinguishing this category from its siblings, 7307.92 covers threaded fittings, where the connection mechanism relies on screw threads. Category 7307.93 is reserved for butt welding fittings, which are designed to be joined by welding directly to the pipe. This category, 7307.91, encompasses flanges that do not employ threaded connections or are not specifically manufactured for butt welding.

Within this classification, further subcategories exist to refine the classification based on processing. The primary subdivision relates to flanges that are not machined, tooled, or otherwise processed after their initial forging. This indicates a focus on the raw or semi-finished state of the flange immediately following the forging process. The existence of these subcategories allows for more granular classification, acknowledging potential differences in manufacturing processes and subsequent treatments that might impact their end-use or value.