API RP 583, API 510, and NACE SP0198
- Davits (and Davit Arm Supports): High susceptibility. They protrude through insulation, creating entry points for water. Water often traps around the base/support.
- Lifting Lugs: Very common CUI sites. Welded attachments disrupt insulation continuity; water pools at lug-vessel junctions. Localized CUI around lugs is frequently reported
- Nozzles: Critical risk areas, especially at nozzle necks, flanges, and reinforcements. Penetrations through insulation are prone to sealing failures.
- Vessel Head (Top and Bottom Heads): Susceptible, particularly above stiffening rings or at insulation terminations. Bottom heads can trap water; top heads see runoff issues.
- Platform and Ladder Brackets/Clips: Common water traps. Brackets, clips, and supports create crevices and insulation discontinuities. Ladder clips and platform supports are explicitly called out in standards.
- Manway: High risk due to flanges, covers, davits/hinges, and gaskets. Insulation around manways often degrades or seals poorly.
- Support Brackets and Ring Parts (e.g., Insulation Support Rings, Stiffening Rings): Among the most vulnerable. Rings welded directly to the shell (without standoff/gap)
