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Up Topic Welding Industry / Technical Discussions / B31.1 -Notch toughness
- - By fit.to.a.flange (*) Date 05-06-2008 07:29
I'm struggling here...does anyone can tell me the range of base metal thickness qualified for a procedure qualification in B31.1 if notch toughness is a requirment? As of B31.3, the range is clearly stated in Table 323.3.1 A-5(a).

John boy...
Parent - - By js55 (*****) Date 05-06-2008 13:27
There is no notch toughness requirements in B31.1.
Parent - - By js55 (*****) Date 05-06-2008 13:36
If notch toughness is a project requirment for B31.1 work I would refer to ASME Section IX QW-403.6.
Parent - - By fit.to.a.flange (*) Date 05-06-2008 13:46
Yes, I agree with you to comply with Sec IX QW-403.6, however that would also merely depend on the client's approval. I assumed that when the ASME IX's committee wrote QW-403.6, it was specifically written for ASME VIII, Div 1 requirements. 
Parent - - By js55 (*****) Date 05-06-2008 13:50
403.6 was written as a general recognition of the transition from a plane strain to plane stress fracture phenomen with varying thickness.
Section VIII has its own thickness requirements specific to materials and temperature.
Parent - - By js55 (*****) Date 05-06-2008 13:52
Also, if notch toughness is a project requirment beyond the code then it is incumbant upon the customer to provide you with test temps, thickness limitations, and aceeptance criteria.
Parent - - By js55 (*****) Date 05-06-2008 13:58
Also, I've seen toughness requirements for Grade 91 in B31.1 work. The customer provided the criteria. Keep in mind also that 31.1 stuff is intended for high temp applications it makes no sense to run charpies at low temps (unless you have a concern for winter fab and start up operations). It tells you nothing in relation to the service environment. Common practice is to make sure you are on the upper shelf of the charpy curve.
Parent - - By fit.to.a.flange (*) Date 05-06-2008 14:02
js55,

Thanks for valuable info.
Parent - - By jon20013 (*****) Date 05-06-2008 14:19 Edited 05-06-2008 14:23
Just a word of caution about QW-403.6, make sure you read the MINIMUM thickness very, very carefully.  Most of the ASME B&PV Codes (that I've worked with) do not require notch toughness until the thickness EXCEEDS 5/8 (16mm)... QW-403.6 says the MINIMUM thickness of material qualified, where notch is required is 5/8"... a lot of folks mis-read this paragraph, I'm speaking from personal experience (can ya see me blushing?).  If you want a WPS to be qualified for LESS THAN 5/8" then ya gotta qualify progressively thinner members, or go straight to a 6mm thick part and do your tests on it, as well as your thicker members.   the good thing is if you already have a heavy PQR all you need to do is the impacts by themselves, not all of the other tests, provided all the parameters etc., are the same.
Parent - - By js55 (*****) Date 05-06-2008 14:31
Personally jon I've never misread a code paragraph. For the life of me I can't understand how that would happen.
:)
Parent - - By jon20013 (*****) Date 05-06-2008 14:58
yep, that was a first for me too!!!  As one wise soul pointed out in here Always, Sometimes, Maybe, Except, lol!
Parent - By DaveBoyer (*****) Date 05-07-2008 03:17
I once thought I was wrong, but it turns out I was mistaken. :-)
Up Topic Welding Industry / Technical Discussions / B31.1 -Notch toughness

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