What defines a product as a pipe?

The defining characteristic of a product being classified as a pipe is that its size is determined by a nominal dimension and wall thickness. Nominal dimensions provide a standardized way to refer to the size of the pipe, while wall thickness is essential for specifying the strength and suitability of the pipe for different applications. When discussing pipes, these measurements are critical because they ensure proper fitting, compatibility with fittings and flanges, and appropriate pressure handling capabilities.

While pipes are indeed frequently used for transporting liquids, defining the product solely based on the type of contents it carries doesn't encompass all types of pipes, as they can also transport gases and slurries. Similarly, the material from which a pipe is manufactured—steel or plastic—does not define it as a pipe, as many structures made from these materials might not function as pipes. Lastly, while pipes commonly have a circular cross-section, there are also rectangular or square pipes that are used in various applications, highlighting that cross-sectional shape is not a definitive criterion for classification.