Chrome Molly to Carbon Steel Welding
Chrome Molly to Carbon Steel Welding
(OP)
Welding a P-11 pipe to a P-1 tank do I need to Post Weld Heat Treat the weld or is there a thickness or preheat loop hole in ASME Section IX? Tank is 3/8" nominal SA-516-70 material. Pipe is SA-335-P11. I can also change from P-11 to P-22 or P-5.





RE: Chrome Molly to Carbon Steel Welding
However, I still would like to ask you to re-consider again. What's the reason to use A335-P11 as nozzle for A516-70 Tank?
RE: Chrome Molly to Carbon Steel Welding
If it was for process piping alone, for example,ASME B31.3 table 331.1.1 for P3 alloy steels,equal to or less than 1/2% cr, equal to or less than 19mm, equal to or less than 490KPa/71ksi, no heat treatment,for P4 alloy steel material, equal to or less than 13mm, equal to or less than 490KPa/71ksi, no heat treatment is required, same table for P5A,5B, 5C equal to or less than 3%Cr/0.15%C, equal to or less than 13mm, all MPa/ksi. no heat treatment is required.
Also Para 331.1.3 gives governing thickness criteria for pwht on branch connections, fillet welds, external non pressure parts etc.
Maybe someone else can give you their opinion as well as this is only my interpretation, but i tend to agree with Pan and look at reason for using this class of pipe,hope this helps
RE: Chrome Molly to Carbon Steel Welding
The ASME Code is clear that we are required to PWHT however I'm not comfortable with the disimilar metals during the process. These nozzles are tangental and the tank is as I said before carbon steel and then there is a stainless steel wear plate on the inside. All three metals will be welded together at the nozzle junction and then heat treated at 1,150°. You can see why I have concerns and why I am looking for a loop hole.
Thanks...
RE: Chrome Molly to Carbon Steel Welding
Why is Cr-Mo steel necessary at 710F?
If the impinged surface in the tank needs a SS surface, why not make the inlet nozzle SS too and bolt/weld the steam pipe to it?
Why are they not interested in constructibility issues? What about using preheat inlieu of PWHT - a common practice where such complexity arises?
This sounds like 150 psi steam going into an accumulator - all the fancy materials seem unwarranted to me.
RE: Chrome Molly to Carbon Steel Welding
Sorry I am so late on this response....perhaps you can use it for further instances of this situation.
RE: Chrome Molly to Carbon Steel Welding
RE: Chrome Molly to Carbon Steel Welding
RE: Chrome Molly to Carbon Steel Welding
If this is a repair or alteration then that along with governing state codes may be used.
RE: Chrome Molly to Carbon Steel Welding
RE: Chrome Molly to Carbon Steel Welding
RE: Chrome Molly to Carbon Steel Welding
first ASME SEC 1X does not indicate the requirement of PWHT for P4 materials and you have to refer ASME SEC V111 div 1 only. pwht is required for p4 matl is to improve the ductility which will become hardened while welding. refer the section v111 div 1 for the excemption