Vessel preservation

[HAAQ]

Gents,

We have vessel lined with Incoloy 825. We are going to remove from service for long time.
Can you advise requirement for preservation of vessel during long period of idle?

Appreciating your inputs in advance.

 

[EdStainless]

825 is a high alloy stainless. It should be happy if you would thoroughly clean it, finishing with a nitric or citric acid passivation, rinse with clean hot water, then dry it, cap it off and purge with dry nitrogen. Keeping it pressurized would be good but not necessary. If you don't pressurize it then use packages of descant. These will need to be replaced at regular intervals.

Any vessel left closed for a long period will collect moisture. From the heating and cooling cycles each day eventually there will be condensation. And this water will contain whatever is in the local air. This will settle in low areas. If this is near a chemical plant or the coast you will end up with various acids and chlorides, and this will lead to pitting.

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P.E. Metallurgy, Plymouth Tube

 

[HAAQ]

Thanks a lot EdStainless for your response,

I will be highly appreciated if you advise me with ref. code for this procedure (if any).