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Saline tolerant coatings for buried steel pipelines

2004

Abrasive blasting is not sufficient to remove excessive ferrous chloride contamination of steel substrates exposed to high salinity environment. Cyclic fresh water wash is the proper decontamination process to reduce the level of chloride contamination. In most cases of remote areas rehabilitation works on pipelines, fresh water is unavailable option and the choice of a tolerant coating (solvent or solvent free epoxies) to resist high surface contam. is very limited.

I am looking for a coating system to stand higher surface contamination and provide the life cycle for corrosion protection of buried pipelines in high salinity water table. This maintenance coating is required to be applied in the field. what would be the maximum Chloride level contamination that tolerant coating can take? What are the impirical standards that govern this procedure? What is the industry practice for similar cases and how cost effective?

Fikry Barouky
- Dhahran, Eastern Province, Saudi Arabia

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2004

Hi Fikry,

Re your coating problem, ah, I was never in that industry but only in the corrosion resistant thermoplastics.

I would think that there is a vinyl paint you could use ... certainly there are Urethanes ... but the expensive 2 component Urethane, which I'd assume is highly resistant to saline conditions, maybe the way to go.

Firstly, it is extremely tough. Secondly, it shrinks somewhat upon curing (as do polyesters, vinylesters & Epoxy) by about l0% and hence should give a strong bond all around the pipe.

But I wonder why you don't use PVC pipe or dual laminate PVC pipe (Ive supplied l0" or l2" [I forget] 200 psi pipe in 40' flanged lengths).... or the hdPe pressure pipe May I suggest that you contact some major paint mfgs.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).