PQR for SA-333 Gr6, SA-350-LF2 cl1, SA-420-WPL6 1

[bryancobb]

Doing a Low-Temp bath coil for Canada. MDMT = -50F. Code of Construction = ASME B31.3

I am trying to determine best test pieces to qualify for 2"Sch80 and 1"Sch80.
Pipe, Elbows, and Fittings are in P1/Gr1 and Flanges are in P1/Gr2, per ASME IX.
Impact toughness test are required. Double Bevel groove weld using GTAW on all passes due to small
size of pipe.

My questions are...
Q: Does the flange being in Group 2 require a group 2 material be joined to a Group 1 material for Tensiles, Bends, and Charpys?
It appears to me that QW-424 allows a test piece of 2 pieces of SA-333 Gr6 pipe and that would allow us to weld on flanges in production.
It will be much more costly if a weld neck flange is involved because of flange cost AND test specimen fabrication labor.

Q: Does anyone have a suggestion for a company to do the Lab Testing?
We have already used ATS for one round of tests on two SA-333 test pieces and the results were invalid because subsize specimens were
required and ATS had not applied the B31.3 reductions to Temperature and Energy. Now we have been talking with Ludwig Assoc., LTD. in
Alberta and they are saying a flange must be in the testing. This makes me question Ludwig's reliability since QW-424 seems to disagree.

Thanks in advance for any advice.

Bryan Cobb, ASME QC Representative

 

[metengr]

Q: Does the flange being in Group 2 require a group 2 material be joined to a Group 1 material for Tensiles, Bends, and Charpys?

Yes, because for impact qualification the group number is a supplementary essential variable for the GTAW process (see Qw-256). This means for procedure qualification for impact, group number is treated as an essential variable (see QW-200). Flange material is not needed, only a base material with Group 2 designation can be used.

Discuss the above with the last lab you mentioned. Most mechanical testing labs have limited ASME B&PV Code expertise and they only do what the client requires. So, review Section IX and tell the lab what you want.

 

[stanweld]

Impact test qualify your procedure on SA-516 60 to SA-516 70 plate 3/16" (0.179")inch thick plate in the vertical up position.

 

[bryancobb]

Thanks Stan,

Would that qualify to weld pipe less than 24" O.D.?
I though a plate qualification only applied to large-bore 24" and up?

Bryan

 

[bryancobb]

What THINK I hear you saying, Stan...

Do tensiles and bends from 2 pieces of 2" Sch80 SA-333 Gr6 pipe. That fulfills the requirement for welding pipe less than 24" diameter?
Then do Charpy specimens from 3/8" plate of a piece of SA-516 Gr70 and a piece of SA-516 Gr60, which would fulfill the impact toughness requirement?

AM I CORRECTLY GETTING WHAT YOU ARE SAYING?

 

[stanweld]

WPS qualification need not be done on pipe and has not been so required since the 1974 edition of ASME IX was issued. Welder Performance qualification must be done on pipe. Welder Performance qualifcation on plate permits/qualifies the welder to weld 24" diameter and over pipe.

 

[Kiwi2671]

metengr / stanweld,
Would appreciate some feedback on this subject.

I work predominantly in LNG (low temp) and I have worked as Clients Rep for some major companies including US companies Chevron, Fluor, KBR and I have reviewed numerous PQR/WPSs from other large US companies - CB&I and Bechtel.
They have all qualified their PQRs with SA 333 pipe welded to SA 350 flanges.
Have they mis-interpreted QW 403.5 or do they not have access to the materials Stanweld mentioned ?

Your thoughts greatly appreciated,
Regards,
Kiwi

 

[stanweld]

We have constructed two LNG recieving terminals. In the USA, 49 CFR Part 193 mandates construction to NFPA 59A which mandates ASME B31.3 to govern piping which requires welding procedure qualification to Section IX. There is no requiremnt per the Law to require qualification on SA-333 grade 6 to SA-350 LF2. The requirements regarding P No. and Group no. for impact test qualification remain as per ASME IX. Our low temp carbon steel procedures were qualified on plate. The Operator of the LNG facility may, at its discretion, require pipe materials qualifications.

 

[metengr]

The only comment that I can provide is to amplify the last sentence of stanweld's post above. Ultimately, the client engineering specification or the Engineer of Record decides above and beyond code requirements.

 

[stanweld]

Kiwi2671,
Pipe spool fabricators most often qualify on piping materials.

I have had, on occasion, to mandate additional impact test qualification on production pipe material when I knew that the heat inputs specified were in no way indicative of that actually being used. In those cases, I or my designee witnessed and recorded the parameters during procedure qualifications.

 

[bryancobb]

Stan,

Please give me a "NORMAL" heat input on a GTAW only test on 2"Sch80 at a 600# WN Flange for this material.

(A*V*60)/(TravelSpeed "/Min) = Joules/Min of HeatInput

Assume 2"/Min Travel Speed Looking at the settings on the machine after a pipe to flange weld, it looks like they are using 90A and 15V ...Does 40,500 J/Min. sound about right?

 

[stanweld]

Heat input is in J/inch or J/mm - not J/minute. 40 KJ/in and the heat input parameters described are reasonable. The voltage is probably a bit higher than actual if measurements were made across the terminals rather than across the arc using argon gas shielding.

 

[bryancobb]

Thanks, That was a typo. Fingers going faster than brain Thanks for your Help!!!

 

[stanweld]

bryancobb,
While subsize specimens will be required, be sure not to misinterpret the requirements for temperature reduction under ASME B31.3 and ASME VIII, Div.1.

 

[bryancobb]

Ludwig is doing it for me. I shot the package off to Alberta today. Mr. Langenecker has already went over all the reductions and other small details as I followed him in the code.
He seems to really know what he is talking about.

Thanks to all who commented to help me get a clearer picture of more welding in areas I'm not familiar with.

Bryan

 

[Guest102023]

Since you've mentioned a commercial outfit I will mention mine brimstone56at(a very warm internet email service).
I can provide full service welding engineering consulting and testing for less than Alberta rates.
GRS

 

[bryancobb]

Donde' Esta!

That's what the metallurgists in NC said too, and they sent us on a wild goose chase!

 

[Guest102023]

Around my turf wild turkeys are frequently encountered, along with the ubiquitous non-migrating wild geese. The resulting accumulation of poop underfoot presents a significant hazard.

Weld parameter measurement is best not left to welders, foremen and generic QC personnel who often don't know why it is necessary and can be quite casual about the exercise. In short they should be expertly monitored (so poop does not accumulate, figuratively speaking).

 

[Guest102023]

metengr makes a good point about most testing labs, whose expertise does not go beyond a few bits of Section IX. That was a basic error, but all too common. Similar mistakes also happen with hardness testing on PQRs - techs will substitute alternate methods when they should not, or vice versa, and will use ASTM E140 a little too liberally (and too literally).

When running PQRs on thicknesses that may yield subsize Charpys, choose your base metal thickness carefully (mill it to optimum if necessary), make sure your joint alignment is perfect, and control angular distortion if qualifying on plate. You don't want to increase the temperature penalty by unnecessary extra machining. When your MDMT is -50 on carbon steel, there's not a lot of margin.

 

[mrfailure]

I take major exception to the comments that test labs have limited understanding of the meaning of Section IX or the implication we might utilize the hardness conversions in ASTM E140 or other test methodology too liberally/incorrectly. We do a lot of business pertaining to the B&PV Code and have a thorough understanding of the implications of testing. We also maintain A2LA certification and are audited constantly. We have to; this is our bread and butter. I daresay we are not an exception; this is a basic for reputable mechanical and material test labs.