316SS threaded into carbon steel fitting

[killakella]

Our plant owner is concerned with galvanic corrosion between a 1/2" 316SS MNPT chemical injection quill that is threaded into a A105 carbon steel threadolet. The threads will be sealed with a Liquid-O-Ring 404SYN thread compound.

My thinking is that since the threads are sealed there will be no conductive medium (e.g. water) present for corrosion to take place, so this shouldn't be a concern.

Does anyone have experience with such a situation that could confirm or correct my reasoning?

 

[Unotec]

I do not think you'll get galvanic corrosion. The A105 CS might corrode if you get water, air, etc... into it, though

<<A good friend will bail you out of jail, but a true friend
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[moltenmetal]

You're injecting the "chemicals" into something via this quill: what's the flowing medium, and what are the "chemicals"? If either material can act as an electrolyte, you may have a problem. Or you may not.

The thread sealant won't electrically isolate the carbon from the stainless steel, and it will only exclude water from threads where it's present.

 

[limey1]

Is it possible that you will remove the passive layer from the ss and then impart Iron from the carbon steel, therefore creating the potential for corrosion?

 

[strider6]

You'll have galvanic corrosion if there is an electrical connection between the SS and CS and they are immerserd is an electrolyte (water..). If one of this conditions is not satisfied then you'll not have galvanic corrosion.

S.

http://www.corrosionist.com

 

[EdStainless]

If there is corrosion it will be the Fe that corrodes the fastest. When I have seen this there is often no problem until you want to undo the joint. Then you are in for a repair job.

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