What does the number 2 represent when pipe and fitting sizes are indicated as follows?

In pipe and fitting specifications, the number 2 typically denotes the diameter of the pipe. This is a standard convention in the industry where numerical designations refer to the size of pipes. In this context, a number such as 2 indicates that the nominal diameter of the pipe is 2 inches, which is a common size reference used across various applications. Understanding this designation is crucial because it impacts several factors, including flow capacity, compatibility with fittings, and installation considerations in plumbing and piping systems.

Branch line sizes and other specifications may also use numbers, but they usually relate specifically to the diameter in this instance. Hence, recognizing that the number directly corresponds to the diameter of the pipe helps clarify its usage in system design and installation.