Is dome roof suitable for nitrogen blanketing systems?

[Dome Design]

Dear Sirs, I have a question about nitrogen blanketing, I know the idea of nitrogen blanketing but while design stage of dome roof/cone roof. Should I consider the pressure comes from nitrogen? Because sometimes it exceeds the maximum allowable pressure for dome roof acc. to API650? So can we say that, aluminium dome roofs are not suitable for nitrogen blanketing? Thank you.

 

[IFRs]

Structurally dome roofs can be suitable but over time I've never known one to be or stay pressure tight.

 

[MJCronin]

Be careful of what you mean by "domed roof"

API-650 allows steel domed roofs that have been used for decades with nitrogen purging.

These are completely different than the "aluminum geodesic domed roof" commonly used to keep debris out of tanks

MJCronin
Sr. Process Engineer

 

[IFRs]

MJCronin is 100% correct. My comment was for aluminum triangulated space frame type dome roofs. Welded steel dome roofs are typically 100% suitable for your application. If the tank is small enough for a steel self supported roof (cone, umbrella or dome) that would be my first choice with the choice between cone/umbrella/dome being the design pressure. Ans YES the internal pressure from the blanketing gas MUST be included in the design loads.

 

[Dome Design]

Dear sirs, thanks for replying. Thanks to this kinda forums, as a being junior engineer, I meet with your really helpful experiences. Sorry for confusing, I asked for aluminium type geodesic dome roofs and I got my answer.