stress relieving & normalizing

[lahane1443]

I have to build a spool piece of 54" sch STD having 2 Flare type branch connections of 3" sch 80. The design code is ASME B31.3
The project spec specify material for pipe as SA672 C70 CL32. NACE MR0103 & HIC test is applicable with additional note that all thickness requires stress relieving.

I have separate qualified weld procedure for both normalizing with 30 min holding time & stress relieving with 1 Hr holding time.
The process i have decided to follow is
1] Rolling of SA 516 plate to 54",welding of long seam, perform Normalizing on long seam of pipe.Do 100% radiography of long seam
2] Welding of process Flange to pipe & welding of Flare type nozzle to pipe.
3] Localize stress relieving of branch weld & two cirseam.
Kindly confirm, whether above steps are correct?
Before doing HIC test, which heat cycle i should follow (Normalizing or stress relieving or both) on SA 516 Gr 70 plate.

I have one doubt in my mind that even if, I perform localized stress relieving on cirseam & branch weld, part of long seam of pipe will also get heat treated. so some percentage of long seam of pipe will undergo two heat cycle i.e Normalizing & stress relieving for which i don't have qualified any PQR. I may be wrong but an experts view is highly appreciable

 

[metengr]

Your proposed steps for fabrcation are acceptable. Run the HIC test afer normalizing and local PWHT.

 

[blacksmith37]

You may be able to find A516 plate that has been qualified by HIC testing.Lukins used to offer such a product (if they are still in business). HIC is relatively insensitive to HT. You will be normalizing the whole diameter of pipe , not just the long seam. The PQR /WPS do not require normalize; just that they are performed on normalized material per A672.
Footnote; in 40 yr chem,refinery,pipeline and production , I never saw a flare connection welded on to large diameter pipe.