Dnv-rp-f118 -

DNV-RP-F118

is a Recommended Practice (RP) titled " Pipe girth weld automated ultrasonic testing system qualification and project specific procedure validation ". It provides a uniform guideline for qualifying Automated Ultrasonic Testing (AUT) systems to ensure they meet the rigorous safety and performance requirements of the offshore and energy industries. Core Objective

Industry practice:

Many projects use API 17J for flexible pipe body design, but adopt DNV-RP-F118 for the global system analysis, especially for fatigue and riser interference. dnv-rp-f118

DNV-RP-F118

| Standard | Focus | Key difference | |----------|-------|------------------| | | Integrated riser system on floating units | Most rigorous for fatigue and accidental loads; explicit treatment of FLS and ALS; preferred by European and Asian operators. | | API RP 2RD | Design of risers for floating productions | More prescriptive, less probabilistic; widely used in US Gulf of Mexico but recognizes F118 for fatigue. | | ISO 13628-7 | Completion/workover risers | Narrower scope (intervention risers, not production risers). | | DNVGL-ST-F201 | Dynamic risers (general) | A standard (higher safety level) than RP; F118 is often the companion guide to ST-F201 for floating unit interfaces. | DNV-RP-F118 is a Recommended Practice (RP) titled "

5.3 In-Service Inspection

• Soil stress-strain behavior under large deformation.
• Pore pressure conditions (critical for liquefaction assessment).
• Kinematic constraints of moving soil masses.

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. Soil stress-strain behavior under large deformation

DNV-RP-F118 is a critical document for engineers and designers working on offshore structures, providing a comprehensive guide to geotechnical design and analysis. By following the guidelines and recommendations outlined in the RP, designers can ensure safe and reliable design, reduce risk, improve efficiency, and comply with regulatory requirements. As the offshore industry continues to evolve, the importance of DNV-RP-F118 will remain paramount in ensuring the integrity and performance of offshore structures.

• Noise Filtering: A significant portion of the RP deals with filtering out "false positives" caused by tool noise (wireline rubbing against the pipe) or background environmental noise.
• Reporting: The final report must clearly state the probability of a leak, the precise coordinate/depth of the anomaly, and the confidence level of the finding.

Qualification Components:

The process involves a thorough review of technical documentation, operating methodology, and quality assurance systems. The Qualification Process