Which of the following are accepted pipe weight classifications?

The accepted pipe weight classifications include "Standard," "Extra Heavy," and "Double Extra Heavy." This classification system is crucial in determining the appropriate specifications for various plumbing and piping installations, allowing professionals to select the right type of pipe based on the demands of the project.

"Standard" refers to the typical weight and thickness used for many applications, while "Extra Heavy" denotes a thicker pipe designed to handle increased pressure or weight loads. "Double Extra Heavy" provides even more thickness and strength, often used in industrial settings where the demands on the piping systems are substantially higher.

In contrast, other options include terms such as "Double Extra Light," "Heavy," "Light," and "Single Heavy," which do not conform to the generally recognized classifications in the steamfitting industry. These alternative terms may not accurately reflect the same specifications or standards recognized in field applications. Hence, option B is the correct choice as it aligns with accepted terminology in piping classifications.