Construction zones, plumbing and pipelines would get nowhere in their work if flanges were not available to them. Yes, flanges are an indispensable item in all these areas of work! A flange is a collar or a ring that has holes so that it can be welded or screwed over the pipe or tube end for serving several purposes. Connecting pipes, pumps or valves, changing the course of the pipe work system are just to name a few of them.