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.

The code API 510 covers maintenance inspection, repair, alteration & operating procedures for pressure vessels used by petroleum & chemical process industries.

During an API 510 inspection the inspector will first perform a full visual inspection and understand the vessel history in terms of past inspections and any repairs undertaken. All surfaces must be cleaned and prepared prior to inspection so that visual inspection and UT inspection can be performed.

After visual inspection UT thickness measurements will be carried out on the shell, end caps and nozzles of each vessel. Internal surface cracking inspection using MT or PT will be carried out on a percentage of welds in the vessel with special emphasis on longitudinal welds due to their criticality. A full report of the inspection results will be provided outlining all findings and recommended corrective actions.