AISI 316 in Amine Solutions and NACE MR0175/MR0103

[tesser]

According to later versions of NACE MR0175/MR0103 there are temperture limits on the use of AISI 316 in sour environments. If I interpret NACE strictly then I am confined to temperatures below 60ºC. I am talking about a liquid amine stream loaded with H2S. For example 25%DEA in water at 95ºC containing 2000 ppm w/w H2S.

Does this mean AISI 316 is ruled out according to NACE or does the fact that the amine and H2S are chemically bound make a difference.

Bearing in mind that AISI 316 is common on the more corrosion prone sections of Amine units and temperatures are often well over 60ºC

 

[SJones]

You are not interpreting ISO 15156-3 correctly because you do not appear to have consulted Technical Circular 1 of 15-12-2007. Try doing that and see if it answers your question. Considerations in clause 5 of Part 3 should also help you as does clause 8.2 of Part 1 with respect to your observation

AISI 316 is common on the more corrosion prone sections of Amine units

Steve Jones
Materials & Corrosion Engineer

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