API 653 - Repair of Tank Bottoms - Critical Zone

[JPG1021]

Hello all! I just performed an "Out-of-Service" inspection of a Fuel Oil tank for one of my clients. The examination of the floor/bottom yielded some low wall thickness measurements within the "critical zone". I am familiar with making repairs according to the API 653 Standard but this repair is complicated by a couple of variables and code limitations: (1) The repair area runs right into a lap joint, forcing me to have to "work" the lap patch repair plate over the joint, (2) The repair area is immediately adjacent to a previous lap patch repair plate (which is already 24-inches long, the maximum allowed for a lap patch repair plate in the critical zone). I have attached a picture (hopefully) to help clarify the scenario. It seems to me that in order to strictly adhere to the standard, I will have to replace the floor/bottom sheet to properly repair the condition. I was hoping that someone could offer an opinion or any other options that I may have as I do not think my client is going to be too happy about the amount of work (and money) required to make this repair.