API-650, F.5.1, 11th Edition

[gdubyuh]

In the 10th Edition, Addendum 4, (2) separate area requirements had to be met for the roof-to-shell juncture compression area in F.5.1. The first equation involved the full internal pressure on the roof. The second equation was for 40 percent of the internal pressure.

In the 11th edition, the second equation has been removed. Does someone know the reasoning for the removal of the second equation?

 

[JStephen]

I haven't looked into this extensively, but there were some inconsistencies in Add. 4, and I think still in 11th Edition.

In Add. 4, Section 3.2.1 states that design uplift from wind need not exceed 1.6P as determined by F.4.1. So you have one section limiting wind loading based on construction, and another section requiring construction to be modified to match the wind loading. Perhaps the removal of that equation was a means of reconciling these two sections.