CO2 corrosion inside gas pipelines 1

[Kiranpatel]

I am looking at a wet gas pipeline with a small quantitiy of C02 in the gas composition (1 to 2 % mol). The pipeline pressure is in the rage of 5 to 10 bars.
I think I remember, from a long time ago, about a rule of thumb which states that, below a certain value of partial pressure of CO2, the reactions between the CO2 and the water can be regarded as insufficient to initiate any significant internal corrosion.
Am I talking rubbish ?
If not, can anybody throw some more light on this rule of thumb (what is the threshold value of the partial pressure)?

 

[johnp]

Try the Corrosion Engineering Forum

 

[MortenA]

Your general understanding is correct.

You could try to check out this NORSOK page where they even provide you with a spreadsheet for calculating corrosion:

http://www.nts.no/norsok/m/m50601/m50601.htm

Best Regards

Morten

 

[sloquick]

You may wish to refer to gas quality specifications in gas company contracts that address CO2 primarily to limit corrosion I suppose. Pipeline pressure, steel composition, and trace gas constituents such as oxygen, hydrogen and sulfur may also be important factors.