Coating on carbon fibre epoxy pipe in sea required?

[boeri]

Is an extra anti-corrosion coating on a carbon fibre filament wound pipe line, used on a sea depth of about
3000 m, required? And if so, what would be a good material?

many thanks in advance

Tom

 

[SJones]

Interesting application. What specification is being used for design and material? What will be on the inside of the pipe? For anti-corrosion purposes a coating will not be required but coating may not be ruled out in order to prevent degradation of the composite by seawater adding to that by the conveyed fluid. It would be interesting to see an ISO 14692 qualification for the composite material with simultaneous exposure to 300 bar seawater and the conveyed product.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[boeri]

Hi Steve,
Thank you for your thoughts.
It will be used as a type of oil pipe. On the inside, a steel pipe is used, which acts as a liner. Carbon fibre is used to make it lighter and to provide resistance against the external pressure.

Tom

 

[SJones]

Tom,

I'm not quite sure as to the structural aspects of the application you describe. How is the carbon fibre attached to the steel liner in order to achieve stress transfer across the wall of the pipe? Ameron are developing steel strip laminate pipe which is a GRP with a wrapped steel integral reinforcement to achieve higher pressure capabilities whilst still retaining the density advantages of composite pipe. Perhaps this may be worth looking at although it is in development for onshore applications.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/