ASME BPVC Full Pen Weld for Nozzle 1

[Joe2221]

I have an application where I would like to add a nozzle to an existing legacy pressure vessel. In looking at my options for weld design (UW-16) using full pen welding methods, it seems as though Code requires some sort of backing weld or bar on the internal side of the shell. Is there any option for the nozzle to be added with all welding completed from the outside of the vessel?

TIA

 

[david339933]

There are no backing bars in UW-16. Edit, I see you must be referring to UW-16(b) You can weld from one side without backing. If there is no access to the inside, you could use a borescope to see the internal surface.

 

[r6155]

More data: shell diameter and thickness, nozzle diameter, materials, design pressure and temperature, service.

Regards

 

[SnTMan]

Joe2221, backing rings are not required. The usual approach to achieve a sound, full penetration weld from one side only is careful fit-up, with a TIG root pass. Inspect each side of the weld using any suitable means (flashlight, mirror) and if acceptable, weld it out, using suitable methods.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand