Table 6.1

Date 10-19-2010 03:23

So, do you reject any porosity without regards to code acceptance? Do you reject any undercut no matter how minor without regard to code?

From the Table numbers used I am assuming you are referring to D1.1 Structural Steel Code. As such, there are tolerances allowed for a certain amount of discontinuities. There is no good, sound, reasonable reason to reject welds that the code allows. No one is perfect. There will occassionally be welds with these various discontinuities. Structural is not the same as piping or pressure vessels. Each has it's own set of established tolerances.

It would also make a difference who you represent. The company as in house QC, or the Engineer/Customer. As in house QC you can reject those welds if you want and it is up to the welding supervisors, company officials, and company policy to determine how to procede. With someone that particular the company would have little concern rather a TPI would find any thing wrong with the work. But as the TPI it is not within your pervue to 'reject' welds, only report them as 'Non-Compliant' and let the Fabrication Company determine how they chose to procede. Once the report is in the hands of the customer/engineer, and the fabricator has chosen NOT to repair the non-compliant items, then they, the customer, determine rather to accept or reject the members in question.

Most fabricators will work very well with the TPI to get the work approved without hassles. But you will not do yourself and your customer any good by rejecting acceptable welds. Why would you reject something the code allows? If you are going to make that kind of decision why even pay any attention to the code? Just make it up as you go. Why not say that the welds must be 1/16" larger than what the engineer called for to make sure they are large enough?

Just my two tin pennies worth.

Have a Great Day, Brent

By eekpod

Date 10-19-2010 11:34

I would agree completely with what Brent said. There are times when I get a TPI in here and he tries to strong arm us into saying such and such is bad for whatever reason, I inspect it myself and if I disagree I let him know.
When in comes to undersized welds, and because the code allows 10% to be under, if the weld is only say 4" long then yes we would fix it, but if the weld is 4' long then I would do the calculation to determine how much is allowed to be under, then compare that to how much is actually under.
Now keep in mind there are times when you'll need those tolerances, especially if you are inspecting welds that have been completed and or on a trailer going out, and you'll need a little wiggle room to make sure some issues are acceptable.
just my thoughts also

By jwright650 (*****)

Date 10-19-2010 11:44

I think it depends on the inspector's relationship to the material....If I'm a TPI, then I must go by Table 6.1 and adhere to the letter of the law, if it allows "x" amount of this or that, then I'm obligated to give that allowance, whether I like it or not......but when it's my material, I generally make our guys fix the problem regardless if it is acceptable "as-is". Some things like porosity, even though it may be acceptable, I fix it because it gives an outside inspector a reason to look even harder once he's seen it, and it translates to poor workmanship or poor work ethics on the welder's part. The welder is the first person to see it and should take it on his own to repair it, not let it go and hope someone doesn't see it and call him on it.

By clutch

Date 10-19-2010 15:23

Thanks guys for the input. I will try to explain where I'm coming from. I am a
TPI in the mid west and I've seen a lot of things on structural drawings that makes
Me think the tolerances of table 6.1 are not incorporated in the design calculation.
I see inaccurate weld symbols, wrong joint designations, you name it. It makes
Me believe engineers design the minimum size weld and that's it. They might take
For example take section 2.3.2.8 for fillets and run with it not ever thinking 10% of
Their designed weld could be undersized. Yeah we have that tolerance in our
Back pocket but I'm never dealing with 4' long welds. And yes other discontinuity
Tolerances are taken into consideration but to me that's apples and oranges.
I think engineers expect the undercut, porosity, and profiles will meet the
Criteria but I just believe when they call for a 1/4" weld 6" long that's what they
Need as a minimum.

By Lawrence (*****)

Date 10-19-2010 15:38

No offence intended.

You are making assumptions and decisions above your pay grade. :)

Stick with the advice from the guys. It's real good.

By 803056

Date 10-19-2010 20:48 Edited 10-19-2010 20:50

I can understand where our friend Clutch is coming from in some cases where the welds are relatively short and the call out is for a fillet leg that is relatively small.

For instance, D1.1 allows the root opening between the butting and nonbutting member to be 1/16 inch without correction. Then the code allows the weld to be undersized by a certain amount based on the original leg size (yes, this is a change in the 2010 edition, it is not a flat 1/16 inch any longer). So, let's say a 3/16 inch weld is specified. There is a 1/16 root opening between the two members. With the root tolerance, the load capacity of the weld is reduced by 30%. Now consider the weld is undersized by 1/16 inch for 10% of the full weld length that translates into an additional 3% reduction in strength. The bottom line is the weld has only 66% of the strength anticipated by the designer.

I guess the saving grace is that the allowable stress is only 0.3 times the tensile strength of the filler metal to begin with and the allowable stress on the base metal is only 0.4 times the yield strength of the steel, but no more than 0.6 times the minimum tensile strength of the steel. Thank the Lord for safety factors!

However, back to the original question, I have to side with the others, any deficiencies are simply reported to the owner and the EOR. It is the EOR's job to determine if the deficiency is acceptable as is or if a repair is required. As the TPI, I try to limit my exposure and take on no more responsibility than required. I am the eyes and ears of the EOR, I am not the judge and jury. A detailed report of the observed conditions is what the EOR expects and that is what I try to provide. My job does not include arguing points of the code with the fabricator's QC department. Depending on the job requirements, I may not even mark the deficiency on the member involved. Again, the detailed report that includes the member's identification, the affected fitting, and the deficiency are what the EOR needs to make an intelligent decision on whether a repair is required. It is important to note all the deficiencies observed, while the undersized weld is important, the presence of transverse undercut, piping porosity in conjunction with the undersized weld, or the crater crack may be more interesting to the EOR than the fact that 12% of the weld length is 1/16 inch undersized.

Best regards - Al

By eekpod

Date 10-20-2010 10:20

I don't think the EOR take the values of Table 6 into account when they call out weld sizes and joints, I am under the impression that it is only for the fabricator and thats it. Now don't forget an engineer can override the code, they have that authority, we don;t as indpectors.
I have seen many a drawing with the wrong weld symbols, its just part of the process, doesnt make it right, but its just how it is. It comes down to commom sense to determine what the part configuration is and what what weld needs to be put there.
Not so much any more I think I have gotten it fixed but used to be a problem was a fillet weld symbol where a flare bevel joint is, say a flat plate welded to a square tube, we know what they want but they used the wrong symbol.

By 803056

Date 10-20-2010 21:16

You scare the hell out of me eekpod.

I question every weld symbol that isn't correct. If the designer can't take the time or doesn't know his welding symbols, what are the chances he can properly size a weld?

Besides, that telephone call is billable time! ;)

Best regards - Al

By waccobird (****)

Date 10-20-2010 21:50

Al
I also question every weld symbol.
As I have stated before I either give the Engineer what is called for in the contracts or RFI it to Engineer to confirm. I am not beyond delving into the contract's Documents and checking to make sure the detailer has it right.

Marshall

By 803056

Date 10-20-2010 22:38

Better to ask a question than to make a serious mistake.

Best regards - Al

By eekpod

Date 10-21-2010 10:21

wish I had the time to question EVERY weld symbol. But when they get it right on 5 other sheets and they get it wrong on one, and all the parts are EXACTLY the same except for length, it's safe to say the weld symbol is the same for all the pieces.
Besides who doesn't like to blame the detailers for all thats wrong in the world :)

By 803056

Date 10-21-2010 16:02

The receiving inspector. ;)

Al

By ssbn727 (*****)

Date 10-21-2010 17:31

Very interesting when the term "Weld symbol" is thrown around so loosely because this term is only referring to a part of the welding symbol which indicates the type of weld and, when used, is a part of the welding symbol.

Now "welding symbols" consists of several elements including the weld symbol... Only the reference line and arrow are required elements. Additional elements may be included to convey specific welding information... Alternatively, welding information may be conveyed by other means such as by drawing notes or details, specifications, standards, codes, or other drawings which eliminates the need to include corresponding elements in the welding symbol.

All elements, when used, shall have specific locations within the welding symbol
(Refer to figure 2 on page 3 in ANSI/AWS A2.4-98.. quickest one I found ;) ) Mandatory requirements regarding each element in a welding symbol refer to the location of the element and should not be interpreted as a necessity to include the element in every welding symbol.

So please let's get the terminology correct here! ;)

Respectfully,
Henry

By 803056

Date 10-22-2010 12:52

It reminds of the fella that told his doctor he wanted to be castrated.

Al

By MBSims

Date 10-23-2010 21:40 Edited 10-24-2010 01:43

The undersize tolerance has already been justified by the D1 committee through the design requirements for sizing welds. A minimum safety factor is already built in. Welds are not sized so "marginal" that an inspector must take responsibility for ensuring the design is sufficient by over inspecting them. The practice of applying a standard tighter than the requirements does not help anyone. The fabricator will consider the additional cost of over-inspection in their bids, so the price goes up and they may lose the bid. The purchaser does not get a better product, and his cost goes up also. The inspector develops a reputation as being more stringent than necessary and may not get called to inspect the next project or lose their job eventually. No one benefits by this practice.

By mistaway Date 10-23-2010 01:46

Has anyone had any dealings or business with Leedon Inspection out of Midland Texas? Trying to find out if it is a reputable company? Does anyone know their Chief Inspector Mike Ruud?

By 803056

Date 10-23-2010 15:57

Only after the operation did he learn the correct term was "circumsized."

Ouch!

Henry, I couldn't have said it better.

Best regards - Al