Double Wall Tank

[Manufacturer02]

How do I know what pressure to consider in a space (interstitial) between two walls of double wall vertical steel storage tank? The primary tank should be at atmospheric pressure.

 

[IFRs]

Both should be atmospheric if they were built to API 650

 

[Geoff13]

Why is your tank double walled?

I can think of some services that would be atmospheric, and others that would be pressurized.

 

[IFRs]

API 650 petroleum storage double wall tanks are typical where real estate is not available and the exterior tank serves as containment in lieu of a bund or dike area. For instance for gasoline or jet fuel storage in cities fed by pipeline and emptied by trucks. These tank systems are both atmospheric by design.

The OP needs to clarify what standard or code their tank was designed to before we go any further.