Release Prevention Barrier under tank in use (soil foundation)

[saifkk2000]

Dear All,

We are working on a tank in refinery. Initially our scope was to replace the tank bottom but later client's inspection department added some additional job i.e. to install release prevention barrier under the tank bottom.

Now i want to clarify the following:
1. Can we install RPB under tank bottom having soil foundation?
2. API 650, Annex I has few methods to install RPB under tank bottom. Personally I did not see ant case having soil foundation so from my point of view it is not applicable in our case.
3. I also want to inform you all we did the same job for 3 tanks last year but we never installed RPB under any.

Please if anyone knows about this case, kindly provide me details.

PS: I have studied API 650, API 653, Saudi Aramco Standards (SAES-D-108) for the above but there is nothing mentioned clearly regarding soil foundation case.

Regards,
Khan

 

[IFRs]

One common solution is to install a second bottom above the existing bottom giving you double containment within the tank envelope. However this does not address a RPB outside the tank to the dike wall.