UT of partial penetration welds

Date 08-06-2013 03:39

Partial joint penetration groove welds are not usually subject to testing with UT.

In some instances the UT may be used to determine if the required weld size is present, but someone needs to check to see if NDT other than VT is required by the contract. If not, the Owner can be stuck with a sizeable bill for handling, preparation, testing, and repair if the welds are deficient.

Best regards -Al

By welderbrent (*****)

Date 08-06-2013 03:44

Beat me again, yeah, there's that too. He always explains it so good.

Have a Great Day, Brent

By welderbrent (*****)

Date 08-06-2013 03:42

Why would the UT tech be looking for anything? You might try telling us what code you are working to? What your specs call for?

The information presented doesn't really get us very far.

Have a Great Day, Brent

By greek

Date 08-06-2013 13:28

The specs call for UT of 20% of partial penetration welds

The Code is AWS D1.1

By welderbrent (*****)

Date 08-06-2013 14:16

More than likely you are back to what Al stated and I was hinting at with my questions: they want to confirm depth of penetration.

In case you, or someone reading this doesn't know, your fraction on the right in the parenthesis, '(5/8)', is the weld size/thichness. The fraction on the left, '3/4" ', is the depth of bevel. So, either your plate is already 3/4" thick (which we know from your OP that it is actually 1") and at an angle (30-60°) that gives you your bevel, or the plate is at a T and needs to be beveled for 3/4" out of the 1" thickness. Then, the engineer and/or detailer has already factored the Z-loss and knows that what ever process is being used will not be dependable, for strength calculations, to penetrate all the way into the root, thus, they give it a 1/8" less weld size than the bevel depth.

So, your UT tech is trying to make sure that the PJP's are indeed getting down to the 5/8" penetration called for on the plans.

Additional note: if there is no weld symbol included for an addition fillet weld after the PJP then the weld only needs to be flush with the edge of the plate. This includes skewed fillets on the obtuse side (larger than 90° angle). The weld size is the penetration, it has nothing to do with any additional weld reinforcement beyond the full weld depth of being flush with the plate.

Have a Great Day, Brent

By jwright650 (*****)

Date 08-06-2013 14:22

>your UT tech is trying to make sure that the PJP's are indeed getting down to the 5/8" penetration

...and making sure there isn't a lack of fusion along the bevel/groove faces down to that 5/8" of depth. Be sure to map out the joint so that you know that you are covering all of that area sufficiently with sound...and it lets you know where to expect to see the bottom.

By greek

Date 08-06-2013 14:46

Thanks guys this helps alot :cool:

By 803056

Date 08-06-2013 14:49 Edited 08-06-2013 14:53

What is this "lack of fusion you speak of?" :roll:

And I am confused about the skewed fillet. If I am reading D1.1:2010 correctly, they are no longer calling the weld joining two members at a skew of less than 80 degrees or more than 100 degrees a fillet weld. What am I missing? I need help. :eek:

By welderbrent (*****)

Date 08-06-2013 15:50

You are such a perfectionist :lol:

. Thanks Al.

Yes, it is a skewed T joint, not a skewed fillet weld. I find myself still using that designation often to explain to welders what is being asked for because it takes way too long to explain to them that they are not 'Fillet' welds at that point. And it carries over into here.

Have a Great Day, Brent

By jwright650 (*****)

Date 08-06-2013 16:02

>What is this "lack of fusion you speak of?"

...you also have to satisfy Item (2) in the criteria spelled out in Table 6.1.
...so anything less than "complete fusion" is a "lack of fusion". :razz:

By 803056

Date 08-06-2013 16:10

I come from a back water hamlet and I lack the worldly sophistication and expertise of my learned mentors. Therefore I am forced to look up terminology I don't understand. I have two sources referenced by AWS D1.1. Those two references are Annex K and AWS A3.0. "Lack of Fusion" does not appear in D1.1, so I am forced to look it up. It isn't in Annex K, but I do find the term listed in A3.0 as a nonstandard term. Please help. What is this nonstandard term they speak of? :confused:

By jwright650 (*****)

Date 08-06-2013 16:31

To quote another forum member:

>You are such a perfectionist . Thanks Al.

By jwright650 (*****)

Date 08-06-2013 16:40 Edited 08-06-2013 16:46

>I lack the worldly sophistication

Um, what is this term "LACK"...is it similar to "incomplete" :twisted:

Your worldly sophistication is incomplete? :lol:

By 803056

Date 08-06-2013 18:53 Edited 08-07-2013 03:15

I would lean toward incompetent rather than lack of competence.

It is all about words. I prefer incontinence to lack of continence.

Al :grin:

By welderbrent (*****)

Date 08-06-2013 17:18

BUT, since you brought it up, a question to muddy the waters even more...

On the acute side, angles less than 90°, and for this conversation less than 80°, why are the engineers using a fillet weld symbol to designate the weld? Especially past the 60° point, should it not be a bevel groove just as the other side? On the obtuse side the 90° cut at the edge of the plate makes the bevel and creates the groove as the angle is taken to the point where you have separation between one edge of the plate and the mating material and contact on the opposite side. But, is it not true that the acute angle junction between the skewed plate and the base material also form a joint at an angle that would more properly be a bevel groove instead of a fillet weld? They get the bevel symbol on the obtuse and mark it in the tail with a PJP but then put a fillet weld symbol on the acute side. That angle is no more a fillet weld by proper definition than the other one is.

And, if this is correct, then both sides of this joint are PJP's and are not subject to welding by an operator who is only fillet weld qualified. Correct?

(Yes, I am jumping into any book I can find on my computer at the moment to see where I have gone wrong)

Have a Great Day, Brent

By 803056

Date 08-06-2013 18:40 Edited 08-06-2013 19:57

It is back to the 10%-80%-10% rule. Not all engineers or designers are created equal.

D1.1, which is one of the few welding standards that addresses the problems associated with skewed T-joints, states that the welds can be specified by a welding symbol or a sketch. My personal preference is a sketch when the detail involves a welded skewed joint where the dihedral angle is less than 80 degrees or more than 100 degrees.

A skewed T-joint: a standard fillet weld it ain't. The structural welding code for steel recognizes there will be incomplete fusion to the root, thus lists Z-loss to address the condition. I paraphrase: D1.1 states the designer is to specify the effective throat on the contract drawings and the fabricator is to show the weld size as a leg dimension when the dihedral angle is less than 80 degrees. I have to ask you, have you ever seen this done according to AWS D1.1? I have not seen one project where the designer met this obligation.

It is a similar situation with flare bevel grooves and flare bevel V-grooves. I have seen both listed as fillet welds and in several case had the design specify the welds as "full penetration fillet welds" at which point I ask the designer, "What is this full penetration fillet weld you speak of? I can't seem to find it in either D1.1 or A2.4."

Does either situation make it correct just because the engineer fails to do his job?

As for taking the position the welded skew joint is actually a partial joint penetration groove weld, I say no. I rely on a definition I use. No I didn't think it up all by myself. I am not that blessed to be an original thinker. Here goes: A fillet weld goes on the joint, a groove weld goes in the joint. I put skewed T's in a category all by themselves. And that reason I would rather see a sketch of the joint (permitted by both AWS D1.1 and A2.4) rather than it be specified by a fillet weld symbol or a groove weld symbol. AWS A2.4:2007 includes an example of a separate detail showing the required weld detail on page 51, figure 31 - Skewed Joint.

Best regards - Al

By welderbrent (*****)

Date 08-06-2013 19:00

I concur 100%. While you were busy responding, I was busy in my A2.4. I found the sketch you referenced, which we have probably all seen before it just takes an application that brings it into focus, and I agree with your answer. Not a fillet nor a bevel groove.

But, how do we look at it when trying to decide if the welder is qualified to weld it? I would say, even though the engineer called it a fillet, that they need to be qualified for groove welds to make either of the welds associated with that connection. It may not be a true bevel groove weld, but it just as assuredly is not a fillet weld. It is one thing to get a proper sketch on plans to show what the engineer wants, it is another matter completely for us to have to decide who can weld it once we have that detail.

Thanks Al.

Have a Great Day, Brent

By 803056

Date 08-06-2013 20:03

If you have D1.1:2010 handy, check table 4.11. Under the section that addresses fillet weld qualification you will see the welder is only qualified for fillet welds (T-joints an skewed joints) if the dihedral angle is between 60 and 135 degrees.

Then comparing that to the range of qualifications when a grooved plate is welded, you will note there is no limitations imposed on the dihedral angle. I guess that means the welder is qualified to weld skewed T-joints with a verrry small dihedral angle.

Back to AWS A2.4:2007 take a look at clause 6.13. Interesting, very interesting.

Best regards -Al :eek: