corrosion protect by nitrogen

[ilkernet]

hi;
do you know about corrosion protection by nitrogen for steel box section?

 

[unclesyd]

Dry nitrogen will help in a leak proof system. You will mitigate nearly all the O2 driven mechanisms and if the moisture is low enough you get all the anaerobic systems. The rub comes when you try to back fill with N2 having to clear all the O2 and moisture. It is hard and expensive to get a 100% or good N2 atmosphere. Having said all that you can get a lot of relief from corrosion if you can allow a little to start with of use a VpCI with the N2.

Can you comeback with a little more information about size etc.
Just remember that N2 in an enclosed space is lethal for human exposure.

 

[kelowna]

Never heard of corrosion protection by nitrogen. On bridges it is becoming quite common to use de-humidification systems inside steel box sections, but nitrogen?

Unclesyd raises very good questions. The steel box would have to be airtight to keep the nitrogen inside once placed. Also, pumping air out and nitrogen in would be a problem, and certainly inspection would not be possible or very difficult. Besides, if you make the steel box airtight, then nitrogen would not be required to prevent corrosion, just dry the air inside and close the box. No moisture, not rust.