ASME B31.3

By jon20013 (*****)

Date 10-14-2011 12:20

Good question and required enough thought I almost thought to not respond :smile:

but here are my opinions:

Q1) seems odd and almost contradictory to say: "If a welding procedure has been qualified by impact testing for service at a temperature of −46°C in accordance with para. 323.3" and then follow on saying: "but the base material and weld material were impact tested at a warmer temperature in accordance with their respective material specifications,
may the weld procedure be used for service at temperatures as low as −46°C?"

How could the base metal and weld metal be qualified at a warmer temperature when the first quoted sentence is to stand? In any case, I would say for the base metal but NOT the weld metal see Note 2 of Table 323.3.1.

Q2). Would ordinarily respond with a "no" not required but if using a "G" designated filler then would respond "yes" same brand and batch number of material must be used.

By nantong (**)

Date 10-15-2011 04:11

It is my understanding that the procedure was successfuly tested at -46C using materials that, say were certified good to -20C.

The answer from ASME to question 1) is Yes, provided the essential variables, and supplemental essential variables in ASME Section IX, are met.

The answer from ASME to question 2) is No

I am really surprised at the answer to question 2). How can you be assured that a different batch will be good at -46 also. In my experience I have got away with using a 70X class consumable where it should have been a 80X class consumable (trying to keep hardness down). This was only possible by using the same batch of consumables for all production work.

This is in Interpretation 22-01

Hope someone could explain this to me

By jon20013 (*****)

Date 10-15-2011 05:54

So, silly question maybe but why are you posting these questions when ASME has already answered?

I'm not surpised by answer to question 1, but I will take an issue back to ASME for question 2.

I could agree with answer to question 2 (see for example A5.6; para. A6.11.3 (impacts) BUT also from A5.5, read para. A2.3 “G” Classification, last sentence: This means, then, that two filler metals, each bearing the same “G” classification, may be quite different in some certain respect (chemical composition, again, for example).

That's the reason I mentioned in my earlier response.

I know for fact that ASME IX limits the use of "G" classified electrodes to manufacturer and trade name (not necessarily batch but that is also limited in some project specifications as well as pipeline codes).

By nantong (**)

Date 10-15-2011 10:30

Sorry Jon, I came across this at work before but only came across the interpretation recently and I was surprised at the answer.

OK it may be a bit remiss of me not identifying that it was a query on an ASME interpretation by someone else who had in part similar thoughts however I wanted an unbiased answer or should I say someone else to consider this who has the background and experience such as yourself, purely focusing on the question and not the answer.

Apologies if you think I was underhand.

I do appreciate your input.

By nantong (**)

Date 10-15-2011 11:01

Jon, I was not aware of the restriction of G class in ASME with regard to source. I would be grateful if you could tell me where this is.

I agree some specifications made this an essential variable eg British pipeline specification BS 4515 1984 edition. If you qualified on Vallourec pipe you could not weld BSC pipe or even one BSC pipe from one mill to a different BSC mill's pipe. Welding consumables were even a greater enigma. They could come from Waltham Cross for one major manufacturer or from Nijmegen for another but as these companys had manufacturing plants throughout Europe and boxed at one location how could anyone know the actual source.

By jon20013 (*****)

Date 10-15-2011 11:55

No worries nantong, I'm actually glad you posted the question because I believe Interpretation 22-01 is only partially correct in the response to question 2 and have asked some ASME colleagues for clarification.

You can find reference to restrictions in ASME IX when using "G" classified fillers here: http://www.sperkoengineering.com/html/articles/2008_addenda.pdf

It is also stated within the A / SFA Specifications although one needs to read carefully to pull the true meaning from the language used.

Admittedly, for codes / standards outside of the USA / ASME systems, they tend to be more restrictive to batch / lots and often require separate qualifications.

By js55

Date 10-17-2011 12:28

jon,
If I understand all this correctly, if the answer to question 2 is not as the committee states you would have to qualify a new procedure every time you get a contract with new materials. This is not the case. The logic is, the procedure has its requirements for CVN's and the materials have theirs. You do not have to requalify a procedure when you change heats but you do have to test the materials.

By jon20013 (*****)

Date 10-18-2011 06:45

Agree, changing heats / lots / batches I wouldn't require a requalification BUT if I qualified with an Elga or Lincoln or (name a manufacturer / trade name) using a "G" classified electrode and then switched to another manufacturer / trade name I believe the intent IS to require requalification.

By js55

Date 10-20-2011 11:58

Agreed.

By jon20013 (*****)

Date 10-28-2011 10:35

I just heard back from one of the B31.3 Members, they are going to bring this matter before subcommittee again. Hopefully it will be clarified.