If you are in the water industry or an industry that deals with pipes, valves, or pumps then make sure you have a copy of the pipe sizes available, internal diameter (ID) and outside diameter (OD), and also the flange types and codes (table, ANSI, etc).
You should pin it to a wall in easy view.
Pipe mismatch mistakes are very common in projects, often because the project manager (or procurement manager in larger projects) did not match the designed pipe ends to the supplied equipment.
If you don’t already have a clear copy of the pipe specifications, most good drafting departments will have one or a source to get one from.