Supported VS. Self supported roof of storage tanks

[Roohol]

Dear freinds!

As per API 650 2011 5.10.5, a dome or cone roof type with rafter & girder and without column is a supported or self supported roof?
And thk of this roof shall be calculated from 5.10.5 formula or 5+C.A is sufficient?

Regards;
Roohol

 

[Duwe6]

Without any columns it is self-supported. Even if there are rafters.

3/16-inch [5mm] + C.A. is the thinnest your roof can be. You have to calc it to be sure that there is sufficient strength present -- supported or self-supporting.

 

[JStephen]

It is not uncommon to see the terminology used either way; if in doubt, ask the person using it to clarify exactly what they mean.