Dnv-rp-f118 May 2026

Based on hundreds of design reviews, here are frequent mistakes when applying DNV-RP-F118:

| Pitfall | Consequence | Solution | |---------|-------------|----------| | Using 1-year instead of 100-year current for VIV | Under-predicted fatigue, risk of through-wall crack | Always check VIV for extreme current, even if probability is low. | | Ignoring installation fatigue | Cracks occur before riser enters service | Run installation analysis with actual vessel RAO and weather delays. | | Mixing safety factors from API and DNV | Inconsistent reliability index | Stick strictly to F118 factors for all limit states. | | Forgetting splash zone corrosion | Localized wall loss, pitting | Add 3–6 mm corrosion allowance in splash zone + CRA cladding. | | No interference check for mooring lines | Chafing and rupture | Use F118 interference criteria (minimum gap + accidental clash simulation). | dnv-rp-f118

DNV-RP-F118 is strict on:

Many FPSOs built in the 1990s are now beyond 25 years. DNV-RP-F118 (2017 edition) includes guidance on: Based on hundreds of design reviews, here are

Any deviation from the RP’s recommended frequencies or acceptance criteria must be formally risk-assessed and approved by a competent person—preferably a DNV-certified marine warranty surveyor. DNV-RP-F118 is strict on: Many FPSOs built in

One of the most actionable parts of DNV-RP-F118 is the checklist for the 5-year special period integrity review. This must include: