API tank supported cone roof repair

[iangineer]

I found this thread (

https://www.eng-tips.com/viewthread.cfm?qid=477970),

but little else that answers my question.

I have a tank that has a few small holes in it and some thin areas. API 653 hardly gives any guidance on repairs for roofs, so we tend to just patch them with patch plates that are OEM thickness with 2" radius corners. We call this a permanent repair since the roof doesn't hold pressure.

These few small holes are not enough to merit replacing a whole roof section. Let me know what you think.

NDE recommendation: VT Prep, PT Root/Final, Vacuum test roof patches

 

[HTURKAK]

I preferred to copy and paste my previous repond to the thread Tank roof repair using BELZONA
thread1452-467276



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API 650,620,2000.. are Construction Standards.
API 653,510,570 ..Inspection standards.
You shall look to Recommended Practices (RP). Regarding the roof repair,

API RECOMMENDED PRACTICE 575 10.3 Special Repair Methods states:
'Leaks in roofs can be repaired by soft patches that do not involve cutting, welding, riveting, or bolting of the steel. Soft patches can be made from a variety of materials, including rubber, neoprene, glass cloth, asphalt, and mastic or epoxy sealing materials; the choice depends on the contents of the tank and the service conditions. The patching is applied in much the same manner as similar patching would be applied to the roof of a building. The patches may be applied when the tank is in service, if proper safety practices are followed. Figure 67 and Figure 68 show a patch and a complete coating, respectively.'


NEW ENGLAND MAXIM Quote 'Use it up, wear it out; Make it do, or do without. '

Good Luck
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Why not BELZONA??