Nozzle tie in welds

[QC1971]

Per section VIII Div 1 the first circumfrential joint falls under section VIII's juristiction. Is there any documentation required from the installer that makes the tie in welds similar to the U-1? Would making these welds be considered field assembly and need to be documented on the applicable portion of the U-1.

 

[gr2vessels]

QC1971,
It seems a bit confusing the way you relate the finalization of the vessel fabrication.
However, the vessel fabricator remains the responsible party for the fabrication, even if the last bit of welding is being completed on site, by law it is under his jurisdiction. The installer (as you name it) shall produce evidence of correct welding, from the WPS/PQR down to the final inspection and tests as per the code and the Client specification and the partial certification as per the code.
The completed pressure vessel is your responsibility regardless where it was completed, hence the 'field assembly' is only a stage of your fabrication and you are still responsible for it. Yes, it has to be fully documented on the applicable portion of U-1 by the party who completed the weld and you have to include the partial report in your final U-1 form.
I wonder how could possible be missinterpreted a such clear definition as stated in the code??!
gr2vessels

 

[metengr]

Per section VIII Div 1 the first circumfrential joint falls under section VIII's juristiction.

No, this is not correct. The weld prep does not the weld joint. Read below.

Please read Section VIII, Div 1, U-1(e)1 ;

U-1(e) In relation to the geometry of pressure containing
parts, the scope of this Division shall include the
following:

U-1(e)(1) where external piping; other pressure vessels
including heat exchangers; or mechanical devices, such
as pumps, mixers, or compressors, are to be connected to
the vessel:
(a) the welding end connection for the first circumferential
joint for welded connections [see UW-13(g)];
(b) the first threaded joint for screwed connections;
(c) the face of the first flange for bolted, flanged
connections;
(d) the first sealing surface for proprietary connections
or fittings;



The weld prep for the tie in welds are under the scope of Section VIII, Div 1. The connection welds are not under the scope of ASME Section VIII, Div 1. These welds fall under a piping code or other specification.

 

[QC1971]

Metengr,

Thanks for the clarification. It has been about 10 years since I have had to deal with Section VIII. After re-reading it I think you are correct.

To clarify the question gr2vessels, a Section VIII vessel is delivered to the jobsite and installed by the onsite contractor who is not affiliated with the original vessel manufacturer. In this case we will be the onsite installer and I was trying to make sure I had everything I am going to need prior to the work starting.

 

[metengr]

Keep in mind the advice I gave is for vessel installation in the US only. Other locations around the world may see things differently and requirements may be differerent. When a vessel is completed under Section VIII, it is what it is, and the stamped ASME data report is complete. Welded connections and other appurtances for a "completed vessel" fall under different codes and standards.

 

[jte]

Seems that this question has been settled; just to add a bit of back up to metengr's guidance:

Subject: Section VIII, Division 1 (1986 Edition, 1988 Addenda), U-1(e)

Question: Two vessels were fabricated by a Manufacturer in accordance with the requirements of Section VIII, Division 1 and were stamped accordingly. Nozzles with weld end connections were provided on the vessels. Are the field welds for the connections to these nozzles considered within the Scope of Section VIII, Division 1?

Reply: No, see U-1(e)(1)(a).

jt

 

[gr2vessels]

The quoted interpretation is quite clear, no comment. It is only my interpretation of the first circumferential weld being exclusively to ASME VIII, regardless where it is completed, in shop or site.
I have to admit that I always considered the first circular weld as a PV weld, not piping, particularly in case of sensitive service where the flanges were not allowed.
That proves once again that there is always room for improvement and learning more...
Cheers,
gr2vessels