Partial Stamping as per ASME VIII-1

[Mec.tec]

A heat exchanger designed on ASME VIII-1 was in service. Now client want to alter some of the design parameter of channel side for e.g increase in MAWP and change of expansion bellow . Due to this change we need to manufacture new channel heads.
Now the fabrication of channels will be done at shop and channels will be sent to site without hydro test(due to unavailability of shell side at shop) after partial stamping.
Please clarify weather the partial stamp (UG-120)is sufficient for vessel credibility as a stamped vessel or further a hydro will be conducted to change it to full U stamp?

 

[marty007]

Typically this would be considered an alteration and covered by NBIC Part 3.

In this situation the following is typically done:
[ol 1]
[li]Component manufactured as ASME PART by U-stamp holder[/li]
[li]Component installed on existing equipment by NBIC R-stamp holder[/li]
[li]Hydrotest performed per NBIC Part 3 by NBIC R-stamp holder[/li]
[li]Alteration nameplate attached to vessel by NBIC R-stamp holder[/li]
[/ol]

 

[metengr]

If this vessel is outside of the US, the NBIC may be used as stated above for documentation purposes. However, a re-stamp of the vessel using ASME will not be done.