API 510 covers the in-service inspection, repair, alteration, and rerating activities for pressure vessels and the pressure-relieving devices protecting these vessels. This inspection code applies to all refining and chemical process vessels that have been placed in service unless specifically excluded per 1.2.2. This includes:

• vessels constructed in accordance with an applicable construction code
• vessels constructed without a construction code (non-code)—A vessel not fabricated to a recognized construction code and meeting no known recognized standard
• vessels constructed and approved as jurisdictional special based upon jurisdiction acceptance of particular design, fabrication, inspection, testing, and installation
• non-standard vessels—A vessel fabricated to a recognized construction code but has lost it’s nameplate or stamping.