API650 Frangible Joint 1

[Encho]

Hi everybody

My question is the next one:
Is it true that frangible joint is only use for tanks in which internal pressure doesn´t exceed the weigth of the roof?

I am asking because I am about to design a tank with working pressure= 8 in H2O. About this pressure, what should be the design pressure?


Thanks in advance,

 

[fegenbush]

While there is not an explicit restriction on frangible joints for tanks designed to Appendix (or Annex) F, it is unlikely that you will be able to design this tank to have a frangible roof. The minimum compression area required can be determined from F.5.1. If this area is larger than the maximum allowable area for frangibility in 5.10.2.6 the tank could not have a frangible roof.

 

[Encho]

Thanks Fegenbush,

So, if the tank does not have frangible joint. Can I specify any permissible detail of compression ring in figure F-2?


Thanks

 

[fegenbush]

Yes.