American Welding Society Forum
Good afternoon everyone,
We have a project requiring the use of ASME IX 2017, addressing the supplementary essential variables, a code that I am unfamiliar with.
Material is A516-70 to A572-50, with thickness ranging from ¼” to 3 1/4", FCAW will be used exclusively and will require PWHT and toughness testing.
From our understanding we will need two PQRs; one at 1/4" and one at 1 1/2" thick, both being 1G welds. Do we need to cover all (5) PWHT conditions as stated in QW-407.1(a)? Or because a change in the PWHT is a supplementary essential variable, only the one that applies to our stress relieving is required? If this is not enough information, please let me know and I can elaborate.
I would appreciate it if the replies include where the information is referenced in the code.
What is the code of construction?
Why do you need 2 PQR's?
"Do we need to cover all (5) PWHT conditions as stated in QW-407.1(a)?"
I would assume NO but with out any further information, one can only guess.
The code of construction is ASME VIII division 1 2015 edition.
Two PQRs to cover the range of thicknesses due to us needing to use the supplementary essential variables.
we do need some more information, such as, COC that applies, such as ASME B31.3, or ASME Sec. VIII Div. I, etc. etc., and since you are having to address supplementary essential variables we need to know if charpy (CVN's) impacts are required, if so then what are those requirements. Your answer could change everything else below. Second question. do you need thickness less than 1/4" if so your 1/4" PQ plate should be less than 0.250 (1/4") . Make it 0.249" and you get the 1/2 T, which would give you just less than 1/8" for your min. thickness. If you don't you will only get min. T=1/4". So, with that being said, and the fact that you are not using short circuit mode GMAW, then you are not going to need more than two PQ's. following your thickness ranges, your first PQ should be 0.249 to get you down to 0.124.5" (around 1/8") per QW403-6. (unless you don't need it, then 1/4"becomes your min.) Then your next coupon is 1 1/2" to get you to 8" thick. See QW-451.1. A lot of questions still not answered but at a quick glance this how I see it.
The COC is ASME VIII division 1.
Yes we do need Charpy testing with values at 25 ft/lbs @ 30°.
1/4" is our min. thickness.
Thank you for your time.
Ok. What is the MDMT of your work? Is your A.I been involved in this process of developing PQR's?
I don't know if you know, but I'm curious to know how the test values were determined. You stated that you were going with 25 ft/lbs @ 30°. What sub section of the code was this determined by? I guess what i'm asking is, was UG-84 invoked?
The values were in our spec.
The 25ftlbs. was determined by your customer? The reason why I ask is because if I remember, the ftlbs. only needs to be 15 ftlbs. per Asme Sect. VIII Div. 1; UG-84 and under ASME Sect II Part A I believe the material that your working with is tested at 20 ftlbs. (but you wouldn't be using ASME Sect. II Part A values for your PQR) This is just off memory. Do not quote me on this. Anyways, if the customer called out 25 ftlbs. it is what it is........
Another side note, usually when ASME Sect. VIII is the COC, UG-84 applies and that opens up for another discussion. Production testing is needed to satisfy UG-84. But if UG-84 was not on any documentation from the customer then do not even bother. One other thing, keep in mind that by creating the 2 PQR's, you are missing 0.500" to 0.625" thickness sizes that your able to fabricate with CVN's. Hope this makes sense. Have fun........
I agree with your approach but may I point out that they changed the verbage in ASME IX 2019 (might of been 2017???) to allow .250" thickness to cover down to .125" thickness, therefore not needing to procure and/or machine .249" thk. material in order to address the code correctly. If that makes sense. I would say Steve is in good hands with your help and will gracefully bow out. May I suggest procuring the material with dual certified A516 Gr. 60/70 to cover the different variations of P1; G1 and P1; G2 material. Also, when procuring the material from the vendor, it is a practice of ours to ask that no test values are to be below 50 ftlbs. at the designated temperature. Meaning that any one of the three test values shown on the CMTR shall not be below 50 ftlbs. This is not in any way mandatory and just a suggestion. I mean, who wants material that barely passed right. Anyways, just my thoughts at the moment.
Edit: Didn't realize the material is already P1 - G1; P1 - G2.
Good to know about that code change. Was not aware of that. I was going off memory. I teach my students not to do that because someone might prove you wrong. Good lessons learned. :)
No worries Jim
I know that you didn't take my post in this way but I just wanted to state that I was not trying to prove you wrong in any way, shape, or form but simply pointing out the change. I know exactly what you mean though. Some people get a kick out of correcting others. Not me. I'm here to learn as well, and may I add, your posts on this forum have helped me better understand the various codes when searching for answers to some of my own questions. I'll tell ya, the way they word things sometimes, I mean, you pretty much need to be a lawyer from Philadelphia in order to understand what they are trying to interpret. Any how, looks like Steve is off to a good start. Definitely not a crash course subject, that's for sure. Have a good one!
What we are building is a fish bypass that will be going six levels under water, it is not actually a pressure vessel but the spec calls for it to be welded to the BPVC VIII code due to it being under so much pressure. According to our PM we don't have an MDMT, there will not be a nameplate to my knowledge and no the AI is not involved (at least not in our shop).
As far as the MDMT, this was established in design. Maybe you can ask the engineer that designed this fabrication or is it an old drawing your going by?
I don't want to confuse you so for now I would not worry about the MDMT. It is not needed to create the PQR.
Thank you guys so much for your help.
Without the MDMT does it sound like I'm on the right path with 2 PQRs?
Yes sir. You should be good.
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