U-stamp vessel-modification of internals

[Engman83]

Hi There,

I'm currently working on a project were we are modifying the internals of a vessel that is offshore and in production,built based on ASME codes. As we are upgrading the internals we need to do some cutting of an existing pipe(will be removed) that is welded inside of the vessel. So my question is will this make any conflicts with the U-stamp certification?if so what,and what would be the correct procedure to approach this? Note that there will be no hotwork done at the vessel.

All feedback will be much appreciated!

 

[XL83NL]

Does the internal pipe see a differential pressure, or is it attached to any part that is pressure bearing (feeling differential pressure)

 

[marty007]

Is this an internal projection of a nozzle?

 

[Engman83]

Hi,

The pipe is just an internal extension of the outlet nozzle,but needs to be cut out as it is currently conflicting with our internal design. There are also some vortex breakers that is welded to outlets that needs modification(cut). Is there any guidelines/rules in ASME of how this should be done without any impact of the integrity of the vessel shell?(cut distance from weld seem etc.)


Thanks guys!

 

[marty007]

As long as you are working on a non-pressure component you should be okay.

My reason for asking whether these are nozzle extensions, is that you would now have to reference the calculations to determine whether or not the original design was taking credit for the internal nozzle projections. Per Fig UG-37.1, an internal projection of min(h, 2.5t, 2.5ti) can be used for reinforcing the opening. In order to know whether or not you are touching the pressure boundary, you now have to check the original calculations.

Cheers,