API Std for Modifications

[georginr]

What API Std is used when there has been a modification on the original seals of a crude oil storage tank?
It is an aboveground tank with an internal floating roof.
The original design of the tanks used to have wiper seals and was changed to mechanical shoe seals. I would like to know under what API standard do I rely on to inspect if the tank is adequate for mechanical shoe seals and if there are other changes needed such as rim vents and roller guides for the floating roof or other adjustments I am not aware of.
Thanks.

 

[IFRs]

API does not care what seals you use. API 650 Appendix H has some standards for shoe seals, but not much. Appendix H has tank shell and appurtenance tolerances for all IFR tanks. IFRs need to have adequate centering and anti-rotation devices as well as proper grounding. 650 Appendix H does cover these. Rim vents are over-rated in my opinion and API 650 does not mention them that I can remember. DavidR@Allentech.com

 

[JoeTank]

Tank repairs and alterations are addressed in API-653. Seals are only mentioned in a very non-specific manner in this standard. The questions you pose are best addressed with a seals / IFR after-market contractor. These are proprietary items that the codes do not address.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com