Deformation on API 650 tank bottom

[tankinspector88]

How can I evaluate if I need to replace a deformed bottom plate?
Its a 12m long carbon steel plate and in some points MFL stucked because the deformation.

 

[JStephen]

API-653 has procedures to determine if a localized low spot in a bottom needs to be repaired.

 

[tankinspector88]

Do you know the section?