Advanced Analysis
Pipeline Free Span Analysis
Free span and VIV assessment of new and in-service pipelines to DNV-RP-F105, from screening to detailed finite element analysis.
Free spans expose in-service pipelines to fatigue damage (FLS) and local buckling failure (ULS). Vortex shedding, causing in-line and cross-flow vibration, and direct wave action accumulate fatigue in a span; static bending, VIV, waves, currents and trawl gear interaction all contribute to local buckling.
Z-Subsea Energies has extensive experience of assessing free spans on in-service pipelines, fully in line with DNV-RP-F105 “Free Spanning Pipelines”. Allowable span lengths must protect the pipeline against fatigue damage, local buckling and trawl gear interaction.
What’s included
Screening, response-model and finite element assessment
In-line and cross-flow VIV and direct wave loading
Fatigue (FLS) and local buckling (ULS) checks
Trawl gear interaction
Multi-span, multi-mode FE for single, pipe-in-pipe and piggyback lines
Spans found in survey on in-service pipelines, with mitigation and repair options
Common questions
Which levels of free span assessment do you carry out?
Screening, response-model and detailed finite element assessments to DNV-RP-F105, covering fatigue from vortex-induced vibration and wave loading, local buckling and trawl gear interaction.
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Free Span and VIV Assessment
Capability statement: free span and vortex-induced vibration assessment of pipelines and risers.
Case studies
Delivered on these projects.
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Talk to us about pipeline free span analysis.
Tell us about the asset, the standards and the schedule — we’ll take it from there.