Split Reinforcing Pads 1

[solidhardhead]

Often times a reinforcing pad is used on a pressure vessel nozzle and the pad must be split during the fabrication sequence. Under the rules of the Code must I compensate for a change in joint efficiency of that re-pad due to the long seam which it now has? If so, by x-raying that longseam can I now use a JE of 1?

Thanks...

 

[doct9960]

solidhardhead,

Split repads are not addressed by the Code. Check with your jurisdiction for directives.

Here in Alberta, Canada, ABSA has issued a directive on split repads...

http://www.absa.ca/IBIndex/IB05-004R1.pdf

http://www.absa.ca/IBIndex/IB05-005.pdf

 

[SnTMan]

Excellent links, doct

 

[Konrad]

solidhardhead,
this issue was discussed a time ago here:

http://www.onetb.com/forum/ftopic86.html

Konrad

 

[Shmulik]

Please note that welding of repad's parts together will be probably applied when it is attached to vessel's shell. The clearance beneath the pad is likely being split, as the welder will do his best to achieve a proper full penetration weld.
Therefore, Telltale Hole should be preformed on each part of repad.

You may find Telltale Hole requirements at UG-25(e) ; UG-46(b) ; UW-15(d) ; UCL-25(b).

 

[twistobar]

One of the Code Sub Groups considered this issue a couple of weeks ago.
The prevailed opinion was that since a shell serves as a permamnent backing strip for a repad, the Code intent will be met by just monitoring the quality of the full penetration split weld.
Regards,

... a man's got to do what a man's got to do...

 

[juancito]

Besides, is suggested to orientate the "diametral" seam of the re-pad circunferetially in order to be "caught" by the longitudinal stresses of the shell.