Issuing body
API
Latest edition
5th Edition (2014, A3 2020)
Region
USA, Global
Equipment items
4
Scope
In-service inspection and repair of API 650 and 12C tanks.
Key requirements (7)
- Applies to API 650 / API 12C atmospheric storage tanks in service.
- External inspection ≤ 5 years; internal ≤ 10 years (extendable via RBI to 15–20 yr).
- Bottom MFL/UT scanning during internal inspection — quantifies underside corrosion.
- Settlement survey at intervals (cosine-curve fit, edge settlement criteria).
- Reconstruction: hydrotest required after major shell replacement.
- Authorized Tank Inspector (API 653 ICP) required.
- Repairs categorized as 'Major Alteration', 'Repair' or 'Routine Maintenance' with different documentation.
Related standards (2)
Applied to 4 equipment items
Inspection & Process Safety