API 650 - Appendix F

[danielmsei]

I am having problems determining what "internal design pressure" API is reffering to in a lot of ther interal pressure calculations. In section F.4.1 they give you an equation for "P" which defines as "internal design pressure", but the equation has nothing to do with the actual desing pressure. Is F.4.1 "P" actually a maximum design pressure on the roof to shell connection? And i.e. in the equations F.7.5 for design of uplift do they mean the actual design pressure or the equation F.4.1 "P" design pressure?

 

[JStephen]

The equations giving P as a function of other variables are giving maximum values of P for the conditions indicated. In other places where P occurs, it will generally be the design pressure, which is not normally the same as either of the maximum value.