RF Pad weld sequence in Pressure vessels

[vesselrajj]

Hi guys,
Recently I come across one vessel Inspector who confused me bit over RF pad welds. In my case, shell thickness is 20mm with inside single bevel (root face 1mm)& external RF pad thickness is 20 mm (root face 1mm). RF pad & shell together forms double bevel geometry with root face of 2mm. what is the advisable weld sequence to fuse or melt this 2 mm of root face to achieve full penetration. Plz share your experience.

 

[GenB]

Hard to understand your post. I believe that if you have the right pre.heat you will not have a problem of just weld over and melt it . Nothing special...

 

[xtrac]

[highlight #FCE94F][/highlight]In my company, we do not place reinforcement until weld shell to pipe joint. That is, weld inside, back goaging outside, and then weld. finally place and weld reinforcement pad.[highlight ][/highlight]

 

[vesselrajj]

Mr.Xtrac,
Thanks for understanding..we also follow the same method as u said. But one of our client inspector suggesting the following sequence. Place pad with nozzle fitup.Filling the groove between nozzle&pad.As per him, now the rootface of pad is completely get melted and shell rface is partially melted. Back gouging from shell inside and welding.During welding from inside of shell, the partially melted Rface of shell also get fused completely. I think he is correct.Bcoz in our traditional method(as stated by you), the possibility of RF pad bevel fusion is not 100% as per my view. whats your view?..

 

[gr2vessels]

vesselrajj,
Any method proven/approved with your welding procedure can be used. What you cannot do, is to change the approved welding procedure on the basis of a nice advice from an inspector or an engineering forum.
Best regards,
gr2vessels