UG-37 and UG-40 Composite Reinforcement of Openings

[BradLancour]

I recently encoutered a situation where reinforcement installed on a vessel opening was inadequate per the requirements of UG-37. I have researched a bit on adding secondary reinforcement. I first found reference to it in the Pressure Vessel Design Handbook by Bednar and then I searched Code Interpretations and came upon VIII-81-28, where the question was asked, May a second reinforcing pad of smaller diameter than that attached initially to a vessel and nozzle be added to the initial pad,... reply: Yes
in reference to, thread794-320779

Does anyone know of specific prohibition of this in the current Code?

I assume the total element area, A5 would be the summation of each reinforcing pad area.

Any guidance on this would be appreciated.

Regards,
Brad

 

[Fizza453]

The addition of second RF pad on the existing one is not prohibited in current Code Edition and Addenda.
The interpretation you have cited is still valid.
You need to take care of opening paragraph of UG-82, RF pad should have such a curvature so that it may reasonably fit on the existing one.
For the filler metal, take care of second last sentence of UG-41(a) so that area A41 and A42 may be fully credited.
Distribution of the required reinforcement area shall be uniform on each side of center line of the opening so that last sentence of closing paragraph of UG-37(b)(5) is satisfied.


Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN