Nozzle neck thickness per UG-45

[MikeG7]

Dear Forum members, happy new year to you all! Hope it's a great year ahead.

For the thickness of a nozzle attached to a welded flat cover, do you calculate tb1 (minimum thickness of the shell or head with E=1) as you would if it were a formed head, e.g. a toris. head?

For reference I have posted the relevant wording:
for vessels under internal pressure, the thickness (plus corrosion allowance) required for
pressure (assumingE=1.0) for the shell or head at the location where the nozzle neck or
other connection attaches to the vessel but in no case less than the minimum thickness specified for the material in UG-16(b)

Thanks
Mikeg7

 

[gr2vessels]

The welded flat cover thickness is calculated as per UG-34.

 

[MikeG7]

Gr2vessels
So I assumed, it's just that since flat covers usually much thicker than other heads, and the formulas in UG-45 have also relate to the component to which the nozzle is attached, it yields a required nozzle thicknesses that are on the heavy side. If the same nozzle was attached to a different head, not a flat one, the nozzle would be allowed much thinner wall. Just trying to understand the logic here a bit better.

 

[MikeG7]

Gr2vessels
Never mind I think I got it now. I take the THINNER of the head or values of per Table UG-45 + CA (and for a thick head, the values in the table are likely to be less). Thanks.