API 650 Tank Repair required testing

[pneveu]

What are the common tests required after repairs are made to the shell of an API 650 tank? It is 40' tall and holds 10,000 barrels? The bottom course is 1/4" thick. We are planning on replacing an area 10" high by 60" long right above the tank bottom. My take on reading the code is radiography on the butt joints and dye penetrant for the shell to bottom joint. Filling it with water will be an expensive and difficult problem. Will an air pressure test or other testing still be required?

 

[BigInch]

Post this to the API Code forum.

"If everything seems under control, you're just not moving fast enough."
- Mario Andretti- When asked about transient hydraulics

http://virtualpipeline.spaces.msn.com

 

[IFRs]

API 650 11th edtion section 7.3.5 covers testing the shell if water is unavailable.

 

[chicopee]

Hydrostatic test may be omitted with the written consent of owner and API inspector--see API 653.

 

[JoeTank]

chicopee,
It takes far more than approval or agreement of the two parties. There is long and significant list of additional requirements to waive a hydrotest after major repairs.

pnevue,
You need to re-look at the plan. The minimum dimension for a shell replacement plate is at leat 12 inches. Forget the air-preesure test. ASTs are not designed for that condition in lieu of a hydrotest. I strongly recommend that you conduct the hydro. It's much riskier to spill oil than water in the event a serious construction problem.

Also, have you considered a lap welded patch at the base of the shell. It might work for such a small tank. My calcs say it does. And no hydro is required. Check it out.

Joe Tank