PV Internal Parts

[MetalsInc]

I'm having a heck of a time with this one - can't get a hold of the right people to solve this through "the authorities." So I'm looking for some guidance to help me when I do get a hold of these people.

We're being asked to fabricate (weld) internal pieces for a pressurized distallation column. The parts we're making will NOT be pressure containing nor will they be welding to the column/pressure containing parts. They are being "hung" in the column. Do my welds fall under ASME control?

 

[jte]

Metals-

Simply put: No, tower internals bolted into a vessel do not fall under the scope of section VIII.

For a code reference, I'd suggest U-1(e)(2) and footnote 3 which states in part that "... Pads and standoffs are permitted and the scope can terminate at the next welded or mechanical joint."

In essence, a tray support ring welded into the shell is in scope, a tray welded or bolted to the ring is not. Same with welded in beam seats and beams, etc.

However... being out of scope does not exempt the vessel designer from considering the loads imposed by the internals in the vessel design.

jt

 

[MetalsInc]

Thanks. We're not designing anything - just building the pieces that the designer has ordered. It became a question of "do these parts need to be certified?" I've since spoken to the authorities and confirmed that I am not under their control.

 

[unclesyd]

The inside of most distillation columns are not very friendly environments for mechanical components. I would give careful consideration to the quality and craftsmanship that goes into the fabrication of these components.