Carbon Dioxide corrosion

[MaxCarb]

I'm looking for a coating system for an internal epoxy lining of some carbon steel vessels.
The stream is wet natural gas with the presenze of carbon dioxide with a partial pressure under 11 psia.

Thanks

 

[gr2vessels]

Barking up the wrong tree;- ask your paint supplier and make sure he will guarantee the recommended paint system. If feasible, get several offers.
Cheers,
gr2vessels

 

[SJones]

Have a look at NORSOK M-501 and make sure that the supplier's recommendations are backed up with some credible test reports that have included decompression resistance. Journal Of Protective Coatings & Linings (JPCL), July 2002, pp33-37 has some good advice and can be downloaded from

http://www.paintsquare.com

Steve Jones
Materials & Corrosion Engineer

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

 

[strider6]

usually in oil&gas plant i've seen glass flake epoxy for internal protection. The limit of pressure is approx 15-20 bar.
maybe you can find more info on NACE website or the NACE coating network forum.

http://www.nacecorrosionnetwork.com/read/?forum=coatings

hope this help u

S

Corrosion Prevention & Corrosion Control

 

[rodneybennet]

Also check the diffusion & corrosion forum for coatings and composites at

http://www.composite-agency.com/materials-forum.htm.

Specifically take a look at:

http://www.composite-agency.com/messages/4758.html

(this thread is about long term service life of grp under the load of corrosive chemicals).

Regards,
Rodney

 

[MaxCarb]

My paint supplier gave me some coating systems.
In every case, using dewaard-milliams model, i calculated the approximate corrosion rate and i don't think i'll have many problems. Also because i think that this model is very conservative.

 

[strider6]

usually the corrosion model are conservative, it's howerver important to make the correct assumption and evaluation when using a corrosion model. sometimes little change in the input values can give you results completely different.

S.

Corrosion Prevention & Corrosion Control

 

[SJones]

What has corrosion modelling to do with the original question regarding selection of a lining system? Are we moving on to a new question?

Steve Jones
Materials & Corrosion Engineer

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

 

[MaxCarb]

I used dewaard-milliams corrosion model in order to understand if the corrosion rate can cause problems with my process conditions.
In every case my paint supplier gave me a lining system for the co2, in wet stream corrosion attack.

 

[SJones]

So, what did you understand from the modelling and why were you looking for a lining recommendation?

Steve Jones
Materials & Corrosion Engineer

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

 

[MaxCarb]

When i took in consideration the corrosion due to the presence of co2 in a wet stream, i was not worry because the partial pressure of co2 was inside the interval[7psi,14psi],in which "weak corrosion could occur" .And also i have 10 psi only in a KO drum and the stream is wet only when the dehydration unit is in shut-down (a very exceptional case!!!).
Taking in consideration the last case, my owner ask me to change material. Upgrading the material in my case means using SS instead CS. For avoiding this upgrade, i was looking for a epoxy coating system for a carbon dioxide corrosion in a wet system.
The use of dewaard-milliams system is only to understand if, using 3mm of corrosion allowance with CS, 20 years of lifetime of the plant could be granted. But of course, it was only an "academic" attempt, because firts of all it's everywhere underlined that this model is very conservative and then i was taking in consideration the worst case (dehydration unit in shut-down and the plant still in operation).

 

[SJones]

Thanks - that's clearer. It would have been useful if you had put those considerations up when starting the thread.

Steve Jones
Materials & Corrosion Engineer

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

 

[strider6]

it will be necessary to have a look at the process but you said that the partial pressure of CO2 is 14 psi = 1 bar.. with this pressure CO2 corrosion can be a problem..maybe not so weak.. have you considered the stream upstream the dehydration?

S

Corrosion Prevention & Corrosion Control