Dnv-rp-f118
The qualification tests, particularly producing welded mock-ups, can be expensive and time-consuming.
Based on the assessed risk, F118 recommends a hierarchy:
Following the philosophy of DNV-ST-F101, DNV-RP-F118 utilizes a format. It classifies pipeline components based on the consequences of failure:
To fully grasp DNV-RP-F118, it is essential to understand the core technical concepts that underpin its requirements.
Because ground movement imposes displacement-controlled loads (not force-controlled), F118 pivots from stress-based to strain-based design . The pipeline’s capacity is measured by its tolerable tensile/compressive strain—typically governed by local buckling, wrinkling, or girth weld fracture. dnv-rp-f118
The absolute error dispersion between the flaw size measured by the AUT software and the actual physical dimension of the defect.
Where failure implies low risk of human injury and minor environmental economic consequences.
: Analysis of existing detection and sizing accuracy data.
How the soil resists the longitudinal sliding of the pipe. Where failure implies low risk of human injury
Enlarge the population of flaws used for PoD curves, making the statistical results more robust without the cost of welding hundreds of physical samples. Why This Standard Matters
Gravity pulls the pipeline downhill during thermal expansion and resists retraction during cooling.
Ensuring safe installation and operational performance under extreme conditions.
Comparing AUT results against "ground truth" data, often obtained through high-precision Immersion Ultrasonic Testing (IUT) or Destructive Testing (DT). Statistical Requirements The qualification tests
Finally, when the qualified AUT system is deployed on an actual project, a smaller-scale validation is performed to verify that the system's performance remains consistent with the general qualification documents.
Combining AUT results with other Non-Destructive Testing (NDT) and destructive testing to verify accuracy.
The practice establishes specific limit states—such as Ultimate Limit State (ULS) for structural burst or collapse, and Fatigue Limit State (FLS) for cyclic wave and thermal loading—tailored specifically to the dual-wall nature of PIP systems. 5. Installation Considerations