Risers design
Risers design
(OP)
I'm doing clamps spacing calculations for a 6" risers to be installed on a jacket.
I'm using criteria of fatigue analysis due to VIV and direct wave action (DNV RP F105). Are they applicable out of the submerged zone but inside the splash zone? If not, which kind of criteria should be used? Only static?
Thanks for any help
I'm using criteria of fatigue analysis due to VIV and direct wave action (DNV RP F105). Are they applicable out of the submerged zone but inside the splash zone? If not, which kind of criteria should be used? Only static?
Thanks for any help





RE: Risers design
Narendranath R
Pipeline engineering is made easy with state of the art computer software, visit www.narendranath.itgo.com.
RE: Risers design
Pipeliners
RE: Risers design
DNV-RP-F105 covers 'Free spanning of Pipelines' and hence shall not be considered for vertical risers.
DNV-RP-F101 covers 'Corroded pipelines' with assessment mainly based on internal pressure loading only and internal pressure loading combined with longitudinal compressive stresses. One of the exclusions in this RP is that it does not cover 'cyclic loading'.
I think, for 6" dia riser, clamp spacing should be approx 16ft (std weight AISI) or 20ft (Extra strong). Probably consider using Stoke's Fifth Order Wave calculation in combination with API-2A WSD & API-RP1111. If strong wind or hurricane expected geographical locations, try to make it more stringent!