PWHT

[cacacho]

IS A REINFORCED,INTERNAL RING WELDED TO THE SHELL, REQUIRED FOR A PWHT OF A C.S VERTICAL PRESSURE VESSEL 3/4" SHELL thk, 12'-0" I.D X 16'-0" T/T, two 7/8" ell. heads?
There is a concern about deformation of the shell.

 

[metengr]

What does ASME Section VIII, Div 1, Table UCS-56 require?

 

[cacacho]

Thanks metengr,
I was not clear.
PWHT is required per service. The question is addressed to the integrity of the equipment during PWHT.
Is it normal to install an internal reinforcement (ring welded to the shell) to avoid deformation of the shell due to PWHT. The PWHT can really affect the shell (roundness, flattening, etc)??

 

[TGS4]

The vessel can likely be supported adequately during the PWHT. However, I would make it the responsibility of the organization performing the PWHT to provide that adequate support. I have sometimes seen "spyders" on the insides of vessels. I have also designed additional external saddles for tall slender vessels for additional support.

I don't think that welding on rings is the best solution.

 

[cacacho]

Thanks for your help TGS4. I agree.
I just found additional information in other similar thread (2003).