A928 (UNS S32750) Pipe to be used on ASME Vessel 2

[dcox519]

For Duplex 2507 material (UNS S32750), I am working with a few different vendors that are telling me that larger diameter pipe (>8") will typically be supplied as SA-240, rolled/welded with 100% RT, and reference to dimensional tolerances of A928 (but not SA-790, which is the supported pipe material for S32750).

The MTR in-question only shows SA-240 as a reference, then conformance to dimensional constraints of A928. 100% RT was performed, along with some other NDE, but my AI is not accepting the MTR to be used in an ASME vessel. He thinks that, since the MTR only references SA-240, there is no way to tell that the pipe was welded per ASME, and we will need a partial data report of some sort to use the welded pipe (either that, or cut out the weld and re-weld it at our shop). I am being told that a partial data report from the vendor is not available.

I have a metallurgist from one of the vendors that claims the MTR with A928 with 100% RT is acceptable to be used, as there is a clause in the B31.3 book that allows for welded with filler as long as it's 100% X-ray. But how would that allow me to use the pipe in an ASME vessel?

Can anyone share any experience with S32750 pipes for use in ASME vessels, per the MTR call-outs shown above?

Thanks,
Doug

 

[EdStainless]

SA240 isn't a pipe spec, so they can't supply pipe to it.
Pipe in ASME is a material, so the welds are not subject to ASME rules.
The pipe should be subject to an ASME pipe specification.
But if they only want to certify as plate then they would need to prove that they meet ASME rules for the welds as it then becomes a fabrication. And do they hold an ASME stamp?
Why can't they cert to A928, that is a welded pipe spec?
What part of it don't they comply with?
Is it related to the use of filler?
A790 is the correct spec for autogenous welded and seamless duplex pipe.
I have seen A790 at 12", but that is the largest that I have worked with.
And please tell me that you are requiring A923 impact or corrosion testing (don't accept on the basis of micros).
For this alloy such testing should be mandatory.
It is easy to screw up the final solution HT.

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P.E. Metallurgy, consulting work welcomed

 

[dcox519]

It looks like they have certified it to A928 and stamped the pipe "A928 CL 1 UNS S32750". But this is an ASTM specification, so not usable on ASME without reference to SA-790 correct? Or is there something I am missing here?

And to answer the other question, microstructure was satisfactory per ASTM A 923-A and other corrosion test (ASTM G48 Method A) and hardness tests were also performed and found to be satisfactory. HT was completed at 1100°C and quenched.

PMI, RT, and PT were all found to be OK.

Would a U-2 partial data report usually be available for something like this?

 

[dcox519]

I did some more reading into ASTM A928, and Section 6.2 for welding says that all welding of the rolled SA/A-240 plate must be completed according to ASME - excerpt below from ASTM A928/A928M:

Section 6.2 - Welding
Welding procedures and welding operators shall be qualified in accordance with the ASME Boiler and Pressure Vessel Code, Section IX.

So if the pipe is certified to ASTM A928, does that mean they are confirming that the welding was completed per ASME welding guidelines?

 

[EdStainless]

In the future only allow rejection on A923A, require either impact or corrosion testing.

Yes, if they cert to A928 they should be full compliance with SecIX. And they should be more than willing to show the WPS and PQR documents.

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P.E. Metallurgy, consulting work welcomed

 

[dcox519]

My AI likes that A928 requires ASME quality welding, but is still rejecting the MTR because A928 is not in Section II.

UG-8 PIPE AND TUBES
(a) Pipe and tubes of seamless or welded construction
conforming to one of the specifications given in Section II
may be used for shells and other parts of pressure vessels.
Allowable stress values for the materials used in pipe and
tubes are given in the tables referenced in UG-23.

Since A923 isn't in Section II, we go to UG-11 - which requires me to have a partial data report for the pipe since it is a pressure component. Is that correct thinking there?

 

[r6155]

For pipe 8" and larger, why not roll and weld a plate in your shop?

Regards

 

[dcox519]

That will certainly be the plan moving forward (rolling/welding our own SA-240 plate in-house) - we were just trying to see if we could use what we had already purchased. And in the case of the 10" here, already incorporated into a vessel fabrication. We can always replace the section in-question, but why not try to salvage first!

We have some other pipe for future jobs as well where the MTRs show rolled/welded SA-240, them compliance to A928 only - I think we will just locate the L-seam on those pipes, cut them out, and re-weld them in our shop. It would be like SA-240 rolled/welded plate then, in that case.

Thanks for the help all.
Doug

 

[EdStainless]

So the plate meets SA240 and is welded to SecIX rules.
Would he accept if you blacked out the A928 reference?
I don't see what his hangup is, other than he doesn't understand the flow of the requirements.
Have your procurement people hunt for supplier of SA790 on these sizes and save the trouble.

I see where you are going with re-welding pipe, but that gets dicey.
Did you remove all of HAZ? Is your starting material SA240 or A928?
You can do this yourself, but what about heat treatment?
For these grades you want to be in the middle of the specified range, +/-25F (13C) is typical.
If you are at the ends of the range it will skew the A:F ratios significantly.
And of course, water quench.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[dcox519]

I believe the hangup is that we feel a partial data report must accompany the MTR, as it is not exempted in UG-8 or UG-11.

But looking closer at UG-11(d), I am starting to believe that we would be exempted per this section.

I believe that I can make the case that a pipe is a "standard pressure part". It conforms to a standard other than ASME product standard (ASTM in this case), the material is per ASME (SA-240), and all welding requirements of UW-26a/b/c and UW-27 through UW-40 are met. Heat treatment, testing, etc. are all fulfilled on the MTR as well. So UG-11(d)(5) ultimately says a partial data report is not required if these requirements are met.

I am hoping that this will work!

 

[r6155]

I think we will just locate the L-seam on those pipes, cut them out, and re-weld them in our shop. It would be like SA-240 rolled/welded plate then, in that case.

Ummmmmm. Not good to me.

Regards

 

[david339933]

See UG-8 and the associated Endnote 8.
As soon as you add filler metal, it's a pressure part.

 

[dcox519]

Agreed on the UG-8 reference - my AI and I are on the same page here. Until ASME Section II adopts SA-928 into the code as an acceptable material form for Duplex pipe, we will plan on rolling/welding SA-240 on all future projects.

Thanks again for the help everyone.

Doug

 

[r6155]

Interpretation Detail Standard Designation:
BPV Section VIII Div 1
Edition/Addendaara./Fig./Table No:
Subject Description:
Section VIII, Division 1 (1992 Edition, 1992 Addenda);UG-8
Date Issued:
09/29/1993 Record Number:BC93-448
Interpretation Number :
VIII-1-92-168
Question(s)andReply(ies):
Question: Under the provisions of UG-8 in
Section VIII, Division 1, may SA-312 pipe
material be used in Code construction when
such pipe was weld repaired with filler metal
by the material supplier in accordance with
the requirements of the material
specification?
Reply: Yes, this is permitted by the material specification.

---------------------------------------------------------------

Same as above reweld (repair) shall be repaired by the material supplier. See ASTM A 928

Regards