Weld Overlay contribution towards pipe strength calculation

[Meck91]

Folks,

I am working on pipe bends (~30 Degree) with weldoverly.
While calculating wall thickness of pipe, do I need to consider thickness of weldoverlay or just the base material will only be considered as pressure retaining part.

If YES, than how come I know the depth of weldoverlay or penetration into base material, so that I can use the stress valve for base material up to that thickness and for remaining thickness I will use weldoverlay material stress valve. What about heat effected zone in this case???

If No, than it means my base material will only be the pressure retaining part and its thickness must be quite sufficient to withstand pressure. However, in this case as well what will happen to HAZ? because it will alter properties. Or in other words my final base material thickness shall be sum of pressure thickness plus an allowance for HAZ (What would be the appropriate valve for this allowance).

Please also confirm that per ASME B31.3, for cladded pipe, no advantage can be taken of the clad plate thickness towards pipe strength calculation.

Would highly appreciate your help in this regard.

Regards,

Meck91

 

[BigInch]

Not sure about what you're trying to do there, but don't include cladding.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

 

[Meck91]

Thanks BigInch for your advise on Cladding.
Let me clear the other issue.
I have 1/2" wall thickness pipe with 1/4" weld overlay. consider no corrosion allowance. I want to calculate MAWP of pipe, what pipe thickness i have to use for this (1/2" + 1/4") or just base material thickness (1/2"). Will i get any benefit of 1/4" weldoverlay inside pipe towards MAWP.

Thanks

Meck91