API 650 Compression area

[oldisgold981]

Hello guys
i have a question regarding compression area.
as per Annex F 2.2 for self supporting roof the compression area shall not be less than 5.10.5 or 5.10.6.
My question is if we calculate area as per 5.10.5 then we should not be calculating it using F.5.1 am i right?
suppose i have self supported cone roof with internal pressure then i should be using F.5.1 or 5.10.5 ? as there is no internal pressure term in the formula of 5.10.5.

 

[Geoff13]

5.10.5 calculates the area required when the junction is in tension due to the self-supporting roof self-weight and other loads (live, snow, etc).
F.5.1 calculates the area required when the junction is in compression due to the internal pressure.
If you have a self-supporting roof with internal pressure then you must provide the larger of the two areas.

 

[JStephen]

Agree with the above.
The limit in 5.10.5 will not often control the design, for what that's worth.

 

[oldisgold981]

Thank you Geoff13 and JStephen for your response.