Section 9 of the API Standard 653 includes guidelines for the proper alterations and repair to be done for aboveground storage tanks built under the API 650 and 12C standards. It details the requirements that should be followed whenever a certified API tank engineer is replacing, removing, or repairing storage tanks. This also includes the proper installation of tank components defined in the standard manual.
Following the API 653 tank alteration requirements is important because it ensures safe storage and handling of petroleum and chemicals, as well as promotes protection of people working and living around storage tanks and the environment.
An authorized inspector or tank engineer should inspect a storage tank before repairs are to be done. The inspection should follow the API 653 requirements, including the examination method, procedure, acceptance standards, and even the qualifications of the examiner. If repairs are to be done, an alteration order will be recommended.
Contractors cannot start repairs unless there is an authorized order for alterations coming from an authorized inspector or tank engineer. They can only work with the specified alteration and repair work indicated in the authorized order. An authorized alteration order should include design, materials, testing methods, examination, procedures, welding, and work execution.
Approved repair and alterations include works on the bottom, shell, or roof of the tank, such as re-leveling or jacking. Repair work also includes replacement or removal of weld metal or base material of the tank. Reinforcing plates can also be added to existing shell openings, while flaws, such as tears or gouges, are grinded before being welded.
Alterations to the service requirements of the tank should also be approved. This includes decrease or increase in the height of the shell, or changes and additions to the nozzles or man ways.
Work Execution Guidelines
While repairs are ongoing, the authorized inspector or tank engineer should inspect the works done on the tank regularly. Each stage is to be inspected, documented, and approved before moving on to the next.
Now that you know the basics of API 653 tank alteration, you can finally request a formal inspection for your tanks before getting the proper repairs you need.