-
Return to Service of Idled Tanks
Is there any industry guidance out there (within an API standard or other) or do any owner-operators have internal policies around returning tanks to service which have been sitting idle but currently within an acceptable API 653 repair window?
For example…a tank was inspected and repaired in August 2022 to a 10 year interval. After repair, the tank sat idle until now, August 2025, when commercial & operations wants to bring product into the tank.
We have seemingly had issues recently in situations like this where when tanks are idle and the tank bottoms are not in full contact with a sand pad for CP protection so corrosion rates are elevated or the EFR has been on its supports for an extended period of time and that has lead to integrity issues upon flotation (e.g. cracked welds, etc.).
My general rule of thumb is a tank sitting idle for more than 2 years needs a full 653 inspection again, but what is everyone else doing?
-
1 Reply
-
I’ve had experiences with a repaired tank ready to go and sit idle for about 1 year. In this case and all cases we go through our PSSR process to ensure nothing was missed before starting up. But this helps depending on the level of PSSR you have established (i.e. how detailed is the review).
I think if you are worried about accelerated corrosion on the bottom, then rescan the floor, and the one benefit of doing this is possibly extending the internal inspection if you don’t find anything that needs to be repaired within the next 10 years or so. Obviously, you could get the opposite result and have to repair a few things before putting it back in-service.
I can’t speak on your concern about the floating roof, but I’ve been on jobs where an existing tank under repair took longer than a year and the roof was landed the entire time during cleaning, repairs, and coating and there were no issues at startup. That said, I am not sure what you’ve experienced at your facilities and if you’ve had floating roof failures then maybe consider a hydrotest with just enough water to float the roof and inspect.
Log in to reply.