A283 Grade D material suitability in sour service

[Met84]

Please suggest if A283 Gr D can be used in sour service. do you think A283 Gr D plates would pass HIC test? Can we allow this material as compressor diaphragm when it handles sour hydrocarbon gas. Can you share your experiences with such matter? I have heard people arguing that diaphragm is not a pressure containing part so NACE does not apply. thanks

 

[weldstan]

Adherence to the minimum requirements of the specification will assure that plates would not pass HIC test.

 

[SJones]

"NACE," i.e., ISO 15156-2, is primarily dealing with sulphide stress cracking (SSC); its approach to HIC is a little weak. The point of the thread appears to be: "do I need to apply the requirements of ISO 15156-2 to a compressor diaphragm?" To which, the answer would be: if the risk associated with failure by SSC caused by taking no preventative measures is not acceptable, then yes.

With regard to the question of HIC testing, off the shelf material would be unlikely to pass a HIC test with the acceptance criteria of ISO 15156-2. Even if it does, it is still not a reliable result since the steel manaufacturing process will not have been geared towards maximising performance in H2S environments. Technically, it would be classed as "pseudo-HIC." However, is a HIC failure in a diaphragm unacceptable?

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.

 

[Met84]

Thanks weldstan and SJones for valuable inputs. Yes failure in diaphragm (HIC or SSC) is unacceptable option. @ SJones what I understood from the sentence [highlight #FCE94F]steel manufacturing process will not have been geared towards maximising performance in H2S environments[/highlight] is that steel manufacturing process will not produce clean steel which is more likely to undergo HIC. please correct me if wrong.