Tip #02 · Layout
Route for maintenance access first, aesthetics never.
Always verify the revision of the P&ID before starting any work. Check it every morning. Set up a notification system with document control for new revisions.
The best layout is the one a fitter can work on at 3 AM during an emergency shutdown. Every valve needs a body to stand in front of it. Every instrument needs a face someone can read. Every flange needs enough clearance around it that a technician in winter gear can get a wrench on every bolt.
From the book
I have seen designers work for two weeks on a superseded P&ID revision, resulting in complete rework costing tens of thousands of dollars and damaged professional reputations. This is the most preventable mistake in piping design.
The takeaway: Maintenance access is not a secondary consideration — it is the primary one. A pipe that nobody can maintain safely is not a good design, regardless of how clean it looks in the model.
