Recent ASME B&PV Code Committe Actions 2

[metengr]

For those that are interested, there are two ASME B&PV Code Cases (2179-3, and 2180-2) that will be revised to reflect changes in the allowable stress values. These Code Cases pertain to the following materials 9Cr-2W and 12Cr-2W (Grade 92 and Grade 122, respectively). The changes in allowable stress are for the following service temperatures;

Code Case 2179-3 (Grade 92)
Revised Tube Stress column, other column is now Forgings, Pipe and Forged Pipe

Original stress lines

Tube
1050 deg F 17.2 Ksi revised to 16.1
1100 deg F 13.6 revised to 12.3
1150 deg F 10.2 revised to 8.9
1200 deg F 6.9 revised to 5.9

Forgings, Pipe and Forged Pipe
1050 deg F 16.6 revised to 15.7
1100 deg F 13.0 revised to 12.0
1150 deg F 9.6 revised to 8.6
1200 deg F .... revised to 5.6

For Code Case 2180-2

1050 deg F 16.8 Ksi revised to 14.4
1100 deg F 12.9 revised to 10.6
1150 deg F 9.3 revised to 7.2
1200 deg F 6.2 revised to 4.5

Also, the cast version of Grade 92 material is winding thru the Code committees.

 

[deanc]

metengr:

Your opinion please. Revisions to UW-16(f) and where does a "proprietary" fitting fit in?

 

[panduru]

Thank you, metengr.

 

[metengr]

deanc;
I reviewed UW-16(f). Sorry, but I can’t provide any information on revisions to UW-16(f). A proprietary fitting? The Codes and Standards do not endorse or exclude any material based on proprietary or commercial concerns in the industry. Can you provide more information?

 

[deanc]

BC97-311 and ASME B16.9(1.1.2)

I have spoken to others about this but would really like to get your take(you are well respected). Wiggle room? Think the changes will be mandatory 1/07.

I understand why this is being done---but it will have impacts.

 

[metengr]

deanc
I went back on C&S account to review the specific file attachments that you referenced. The revised UW-16(f) that now contains the words "Standard Fittings" in lieu of fittings will definitely cause an impact. I suppose that the Subgroup under ASME Section VIII subcommittee handling this item decided that “special fittings” of the type specifically mentioned in the request for interpretation was not something that Section VIII would endorse, and I would agree. They probably wanted "special fittings" (as agreed upon between the purchaser and supplier) excluded as attachments with only external fillet welds because of the current lattitude in the Code.

I don’t see any wiggle room on this one. Fittings can be fabricated from wrought product forms like pipe or tube, but under this revision, only standard fittings will be permitted with limitations in UW-16 (f) 3 (a).

 

[deanc]

That is the same as I read it. Perhaps a Code Case,but that takes some time. To bad some people abused this "out".

Thanks for looking at this----time to dust off the flak jacket.

 

[metengr]

deanc
I forgot to mention, do you attend any of the NB or ASME B&PV Code meetings? If so, please let me know. We might be able to meet in true identity? It gets tough to meet fellow colleagues.

 

[deanc]

metengr:

I go to the meetings when I am able,but am just a lowly AI who just likes this stuff. Between being a ex boilermaker(please don't hold that against me) and now a AI,I have about 35 years into it. Let me set up an outside email and I will send you an addy.

 

[davefitz]

Metneg:

I understand these alloys ( and T23) obtaine their high temp creep strength based on a bainitic structure, and that normally requires a fast rate of cooling.

Are there published TTT curves for these alloys with the cooling rates defined?

 

[tprimaterial]

Dear metengr,
when will the new version of Code case 2179 and 2180 come out?
We have been using these two materials in our projects, some used the allowable stress values in ASME code case 2179-2 in some earlier untits, however we turned to the data from ECCCC later.
Thanks!

 

[tprimaterial]

For Grade 122, revised allowable Stress is same for tube and pipe? according to a paper by Kimura et al, the allowable stress of tube are lower than Pipe,especially for tubes with dual phases microstructures.

 

[metengr]

tprimaterial;

Dear metengr,
when will the new version of Code case 2179 and 2180 come out?
We have been using these two materials in our projects, some used the allowable stress values in ASME code case 2179-2 in some earlier untits, however we turned to the data from ECCCC later

about 6 months

For Grade 122, revised allowable Stress is same for tube and pipe? according to a paper by Kimura et al, the allowable stress of tube are lower than Pipe,especially for tubes with dual phases microstructures.

yes.