Surface Cleanliness of FJC on Pipelaying Barge (DNV-RP-F102)

[subsealinepipe]

DNV-RP-F102 calls the Field Joint Coating (FJC) applicable on the steel cleanliness of Sa2 1/2 treated by blast cleaning. In offshore FJC is applied on the pipelaying barge, and the field joints are not blast cleaned (there is not blasting station on pipelaying barge, and the field joint are cleaned by wire brush/flame).
The question this is, how FJC as per F102 should be applied on pipelaying barge considering required cleanliness (treated by blasting)?

Regards,
Amir

 

[APipeliner]

For Sa 2.5 look at ISO 8501, it defines requirements for such cleanliness.

 

[SJones]

Read the standard and you will note that, for tape or PE mastic shrink sleeve FJC types, power tool cleaning to St3 is indicated. If you are dealing with the other types of coating and you are not abrasive blasting, coating performance will be severely degraded.

'Bristle blasting' is a very good power tool cleaning method.

http://www.marktool.com/coatings/MBX-Bristle-Blaster

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04