Having good isometric plumbing drawings has always been key for a successful plumbing project. Unfortunately it's sort of a lost art form. Because most of the industry is going to digital media and CAD these programs are used to do isometric plumbing drawings. There is a catch though, if garbage goes in to doing the plan view garbage will come out on the isometric drawings. Quite often it is not a plumber or a PE that does the MEP drawings so they are usually incomplete at best. Check out my set of Waste, vent and water piping isometric drawings. You can use these estimate a job to make sure your fitting counts are correct or you can use them to wrap your head around how the piping should look and make your own drawings to fit your job. I know so many great plumbers and plumbing contractors that can't do isometric drawings if their life depended on it now you can use these to guide your way. Thanks for looking. Sincerely, Sean Kavanaugh