CUI of subsea pipelines
CUI of subsea pipelines
(OP)
Hi,
I am looking for information on Corrosion under insulation for subsea pipelines with cathodic protection. almost all the references I found are mentioning CUI of piping in above ground installations.
specifically, I am looking for some answers to the following subjects. For subsea use (buried 1m minimum in the seabed),
is CUI a problem? Is CP being shielded? can we assume oxygen concentration in the seabed the same in the water? how does temperature of steel effect corrosion rate?
thanks.
I am looking for information on Corrosion under insulation for subsea pipelines with cathodic protection. almost all the references I found are mentioning CUI of piping in above ground installations.
specifically, I am looking for some answers to the following subjects. For subsea use (buried 1m minimum in the seabed),
is CUI a problem? Is CP being shielded? can we assume oxygen concentration in the seabed the same in the water? how does temperature of steel effect corrosion rate?
thanks.





RE: CUI of subsea pipelines
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: CUI of subsea pipelines
thanks for the answer. my concern is coating disbondment for wet insulation systems. I am trying to understand whether CP works or shielding comes into play. as I understand seabed sediments may be deaerated but then how temperature effect corrosion if CP is shielded. or is there no CP shielding at all?
RE: CUI of subsea pipelines
CP will reach the area if there is a continuous ionic path (assuming electrical path is no question). However, CP could be attenuated or even made no working if there is a high IR built along the ionic path. In your case, since the electrolyte is high conductive seawater (smaller R) and it is deaerated (smaller requirement of CP current I), the IR may not be significant. If that is true, CP is still working in that area?
RE: CUI of subsea pipelines
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.