is a DNV recommended practice that outlines the procedures for qualifying Automated Ultrasonic Testing (AUT) systems, specifically used for the inspection of pipeline girth welds. This standard is tightly coupled with DNV-OS-F101 (Submarine Pipeline Systems), providing the validation steps needed to ensure that a chosen NDT (Non-Destructive Testing) system can meet the safety criteria for a specific project. The practice provides a structured approach for both:
The temperature front moves from the hot upstream (platform/wellhead) to the cool downstream, creating asymmetric friction forces.
: For more complex configurations, like double V submerged arc welds, the recommendation can jump to a minimum of 91 samples Implementation in the Field
How the pipe breaks the soil berms over repeated cycles. dnv-rp-f118
The key performance metrics derived from this data include:
For a mooring line, failure probability is heavily influenced by fatigue and wear. For a pipeline, it might be corrosion or spanning.
While DNV-ST-F101 mandates that an AUT system must achieve a for the largest acceptable defect, it does not explain how to prove it. DNV-RP-F118 provides the explicit step-by-step blueprints, math, and testing protocols required to mathematically demonstrate that capability. Core Technical Objectives is a DNV recommended practice that outlines the
To test the detection capabilities, test welds (mock-ups) are created with "seeded" flaws—artificial defects inserted into the weld, such as lack of fusion, cracks, or porosity. These defects are created using mechanical or electro-erosive methods, as creating precise defects purely by altering welding conditions is unpredictable. 3. Statistical Evidence (Sample Size)
There are even industry debates about certain recommendations within the RP. For instance, some NDT experts argue that the use of Immersion Ultrasonic Testing (IUT) for pipeline girth welds, while recommended as an option in the RP, has no advantage over other methods and can be one of the most costly and least useful supplementary NDT options.
DNV-RP-F118 provides essential guidance on handling the increased weight and stiffness of the dual-pipe configuration. It specifies guidelines for monitoring the annulus during construction, managing the localized stresses at the field joints, and preventing plastic deformation of the inner pipe when the system is spooled onto a reel-lay vessel. Conclusion : For more complex configurations, like double V
Ensuring safe installation and operational performance under extreme conditions.
To verify weld quality, the oil and gas sector relies on . However, an inspection system is only as reliable as its validation framework. This is where DNV-RP-F118 ( Pipe girth weld automated ultrasonic testing system qualification and project specific procedure validation ) serves as the global benchmark.
In an era of ever-increasing regulatory scrutiny and aging offshore assets, cutting corners on integrity management is a false economy. offers a battle-tested, practical, and technically robust framework that balances operational cost with risk mitigation.
It requires a high level of confidence in the Probability of Detection (PoD) . For instance, a common benchmark is achieving a 90% PoD with 95% confidence.