API 650 Annex S - Shell Nozzle Thickness 1

[KGTD]

How we should understand the table in point S.3.3.1 about minimum nominal thickness.

In CS tank for nozzles from 8" to 24" we read pipe thickness 12.7mm using the table 5.6a, for SS tank S.3.3.1 gives only information that nozzles above 4" have to be minimum thickness 6mm. The difference is noticeable.
And the question is which value we should take in case of SS tank, higher? Or just simply we take values from S Annex.

 

[IFRs]

If you are making a tank that conforms to Annex S, use the table S.3.3.1 for minimum nozzle neck thicknesses. You do not need to use the table 5.6. Also, follow the note that requires reinforcement calculations per section 5.7.

 

[HTURKAK]

One of the reasons, CA for SS tanks is negligible, while it is around 3mm for CS tanks..BS EN
14015 suggests the following table..