Redesign of existing 12F tank to comply with API 650 2

[DanTh3Man]

Hello,

I have been asked to look into whether or not it is possible to redesign/re-certify existing storage tanks that were designed and constructed to API 12F to be compliant with API 650.

My initial feeling is that this will not be possible due to the more stringent examination requirements of API 650. I think that it also likely that additional venting will need to be installed on the tanks.

It appears that the province of Alberta dealt with this issue a few years ago -

http://ptmaa.ab.ca/index.php/api12f-tanks

If anyone has any experience with this issue I would really appreciate hearing about it.

Thanks.

 

[JStephen]

Generally not.
One issue is the various paperwork/inspection requirements. There's no way to look at an existing weld and say it was done in accordance with the standard. Ditto for the materials meeting API-650 requirements.
Also check top angle details and bottom chime details for compliance.
Also check roof slope for compliance.

 

[fegenbush]

I agree with JStephen that this, if possible, will not be economical.

In addition to the previous items, for 12F to API 650 you will require:
- Radiography of joints
- Hydrostatic test of tank
- Addition of anchorage for wind and/or pressure
- If no foundation is present, anchoring scheme to ground
- Addition of emergency venting apparatus
- Tank grounding, if not already present
- Evaluation of design metal temperature (if below -20°F)
- Removal of square flush cleanout (not permitted by API 650)
- Evaluation of external projection of nozzles