Material Selection Road Map 4

[ChihebG]

What is the Road Map of the material selection in in wet CO2 environments ?
For Example :
How can I assess the severity of the environment?
From what corrosion rate shall I consider other solutions as corrosion inhibitors, ph stabilization or even using CRA?

 

[SJones]

A "road map of material selection" is the holy grail of materials & corrosion engineering, but leads the existence of a unicorn.

To set you out on the path of your epic quest, you can start here:

CO2 Corrosion Search

Here is a magic shield that will be of great benefit:

IFE Guidelines

The righteous choice between the paths of corrosion control or of wondrous materials is oftentimes clouded by the demons of unswaying belief in the total accuracy of the prediction model, optimistic expectations of operational competence, and parsimonious management. Their navigation is not for the inexperienced, or the faint hearted. Fortunately, there are many brave, ancient and wise Knights of the Corrosion Discipline who may be hired to help you navigate these treacherous paths.



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.

 

[metengr]

SJones;
Me thinks you have been playing too many x-box games.

 

[SJones]

Im a PS3 man. Maybe I'll try the next answer under the veil of God Of War

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.

 

[ChihebG]

Thank you Steve.
I think that this isn't a simple issue to deal with. I hope that I can at least elaborate a simple road map that guides mechanical engineers in choosing their materials at my company because they select materials in a non-procedural way but by experience and comparison with similar projects.

 

[metengr]

because they select materials in a non-procedural way but by experience and comparison with similar projects.

This statement alone is what needs to be captured on paper so perhaps you or your company can develop an internal guideline. Experience alone is of tremendous value.

 

[SJones]

Experience and comparison is one way of selecting materials, but it is clearly prone to technical error, commercial error, or both. One of the complicating factors is that it is not only about selecting materials, but also about corrosion control measures. There will also be many strategic and tactical considerations which can only come into play at the time of the study and its subsequent execution. A USD 46 barrel of oil is one such example - you can't write a manual for that one, because it goes straight out of the window. How risk tolerant, or risk averse, is the organisation, as that will have a bearing.

See if the attachment provides any help - it's about as "road-mappy" as I get.

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.

 

[georgeverghese]

Here is a granny formula I've used to guage severity of CO2 corrosion, based on wet CO2 partial pressure:

ppCO2 < 3psi - no measures required

3psi < ppCO2 < 10psi - corrosion management / mitigation by corrosion inhibitors

ppCO2 > 10psi - use CRA materials

Got this from an old Brown and Root design standard, in the days when things were still simple.

In the OpCo I used to work for, all piping and fittings DN50 (2inch) and less in wet hydrocarbons service is made out of SS duplex 2205 (UNS31803) as a minimum.

You may probably have far more sophisticated tools at hand; see if this helps to tell day from night.

 

[SJones]

If the attachment above doesn't work, try downloading it from my LinkedIn profile.

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.

 

[ChihebG]

Thank you georgeverghese .
Thank you Steve, that's very useful.