Welded Manways on ASME VIII Div 1 vessels

[MrVessels]

Is the weld on a 2:1 SE cover on a manway for an ASME VIII Div 1 vessel covered by the Code.
We have several large stamped vessels to be installed in a nuclear waste clean up plant, that after shop hydro and National Board stamping are delivered with a tacked welded 2:1 SE head as a manway cover. All the piping connections on the vessels are butt welded and it is necessary to inspect these vessels for internal cleanliness prior to placing them in service, hence the loose manway cover.
The vessels are designed for 40 years life and are in radioactive service and will therefore not be subject to further inspection once commissioned. In fact the vessels are enclosed in totally inaccessible cells within the processing buildings.
The question is, does the welding of the manway cover need to be covered by ASME VIII by way of an R stamp or can this weld be considered a piping weld under ASME B31.3 similar to all the other butt welds connecting the piping.
This is probably territory for an ASME interpretation but I'm curious to know if anyone has encountered a similar situation previously.

 

[prex]

If that weld could be considered as being outside of ASME VIII scope, then the bolting and cover of any manway nozzle or other spare nozzle could also be exempted.
Another point of view: when a weld connection of piping is treated per piping code, then you have a piping system with an imposed code of practice, but which would be the code of practice of the manway cover?

prex

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[metengr]

Yes, I would expect that the weld on the manway cover would fall under Section VIII, Div 1, and the NBIC (requiring an R-Certificate holder to weld). Look at it this way, the manway opening and cover would fall under inspection openings (UG-46), and are required to be designed in accordance with the rules of ASME Section VIII, Div 1.

 

[solinar]

Its not based on any direct passage of code that I have found, but I have always been told (by National Board Inspectors) if it is required to operate the vessel, its considered to be part of the vessel. For instance spare nozzles are made to be piped up, therefore, their blinds can be considered temporary parts and past the first bolted connection so therefore are considered piping. A manway however will likely always be closed with the cover unless a design change is made, so it is considered part of the pressure vessel even though it is on the other side of a flanged connection.

 

[GenB]

After the hydro, installation pipiong Codes will take over,
Since it is not a repair or alteration, ASME stamping may be required by a PP piping stamp holder,
any future welds after stamping is not your responsibility,
unless you have contracted it.
If you hold your Stamp VIII-1 for field work, you can perform the welding on site, requiring a new certification,
then it may be easyer not to shop stamp but when the job is finished on site. It looks to me that fiel work is not your case.
GB

 

[tickle]

Forgive me for being a little slow. But how was the vessel hydrotested with a tack welded manhole cover? Was a different cover used?

Anyway. If it is a manway cover - presumably it can be removed. If it can be removed it can be hydro tested independently. It can be cleaned etc.

Is an existing cover to be reused. Then this has been tested already and can be used.

I would be looking at whether the manhole cover can be used in service or if it was a transport cover.

 

[GenB]

On this type of jobs the covers are shipped loose and are permanently welded on site.-