Weld access holes

By swnorris (****)

Date 03-02-2005 19:45

Hi Rick,

Sorry. I hit the wrong key and it posted before I finished. If you are welding a web plate to flange plates, you won't need access holes. You will need access holes in the web when you're performing complete penetration welds on the flange plates.

By Rick Nelson Date 03-02-2005 19:50

All that came through on the reply was H.

By Rick Nelson Date 03-02-2005 20:01

We are welding flange to bolting plate. A back up weld is placed on the inside (web side) of the joint then back gouged to the backup weld and effectively to the web therefore the full thickness of the joint is fused. The code is not very clear as to the requirements of access holes but does mention their use ion heavy hot roll shapes.

By jwright650 (*****)

Date 03-02-2005 21:17

Access holes are just that, access for the welder to complete a successful full pen joint.
John Wright

By CHGuilford (****)

Date 03-03-2005 17:47

The TC-U8a-GF by itself does not have any bearing on whether to use access holes or not. Non of the prequalified joints do. The requirement for access holes depends on whether a CJP joint is required and when there is limited access to make the welds.

In a beam configuration, it is easy to see that complete joint penetration would be more difficult at the web to flange junction. It is possible to achieve CJP without the hole but not without large grooves to fill and there is likely going to be some problems with the welds. By using an access hole, it is possible to get at 2 sides of the joint for backgouging, which makes CJP easier and cheaper to do.

Remember too that not all beams or built up members require CJP. There are some times where the engineer allows beams to be spliced without access holes. Just remember that the engineer knows the loads and conditions and can make an informed decision (we hope so anyway, most can). The average welder or fitter should not make that kind of decision for him/herself.

Chet Guilford

By mksqc

Date 03-03-2005 21:23

HI RICK WE DO WHAT YOU DESCRIBE WELD INSIDE AND THEN BACKGOUDGE TO SOUND METAL.AUDITED BY AISC, ICBO, A660 AND CWB AND HAVE NOT HAD ANY PROBLEMS

By Rick Nelson Date 03-04-2005 13:57

I guess the question is: Is that sound metal? Is that proper backing as described by the code? In my opinion it is. The full thickness of the joint is fused and it is a much stronger joint than we had (fillets). That is what is raising all the fuss anyway-cosistently achieving proper fillet size. Anyone been getting dinged by auditors on that? Skewed t-joints, root openings, Z-loss! My calculations show that by following the code our fillet sizes over all will increase by 25% or more depending on fit up. Then comes the fun part, babysitting the welders to ensure proper size on all fillets. I'm rambling now. I appreciate all the feedback on my question.

By jwright650 (*****)

Date 03-04-2005 14:20

page 313 D1.1:2004 Annex B Definitions
backing weld. Backing in the form of a weld.

page 97 Figure 3.4 TC-U8a-GF Notes listed are 1,4,7,10,11
Note 4 in particular says" Backgouge root to sound metal before welding second side"

John Wright

By swnorris (****)

Date 03-04-2005 14:32

Hi Rick,

You mentioned Z loss and skewed connections. Z loss is a dimension that accounts for the lack of penetration to the root of PJP welds. As you probably know, In D1.1, Tables 2.2 and 2.8 provide Z loss dimensions for tubular and nontubular connections for different angles, welding processes, and positions. Also, someone please correct me if I'm wrong, but you can also use note 10, as it applies, (the 45 to 90 degree variance of angles for T-joints) in conjunction with the prequalified PJP and CJP details in D1.1, as opposed to solely using Figure 3.11, Prequalified Skewed T-Joint Details. Also, here's a link to an interesting article from Welding Innovation about skewed connections that you might find useful or helpful.

http://www.jflf.org/pdfs/papers/design_file102.pdf

By Rick Nelson Date 03-04-2005 16:46

I am in agreement with most of the responses. However, does anyone apply these factors to their every day welding? What about adding for root opening? We have a varying degree of weld joint geometry due to material size, joint fit up and angle. There is no one size fits all fix for fillet welds in joints that have material sizes from 1/4" to 1-1/4", roof slopes from 1/4-12 to 8-12, and root openings up to 1/8". Do you over weld all fillet welds to compensate for all cases? Do you have the engineer calculate and size welds for all possible joint configurations? This is why I proposed changing from fillets to CJP and posed the access hole question. Is it acceptable to apply fillets without access holes? Why? I feel there is too much to consider when applying the code to day to day shop welding of t-joint fillets and to monitor all joints produced by all welders is not possible with a staff of two. Welders are welders. I have been one and still weld regularly. Production is king. Quality is secondary at best. Back to the question. Access holes. I have heard from many and I thank you. However, the question has still not been answered to 100% satisfaction. I have been talking on two different forums and it has been a wash. Thanks for the article by the way.

By swnorris (****)

Date 03-04-2005 17:29

Hi Rick,

To answer your questions:

1. Does anyone apply these factors to their every day welding? Absolutely
2. What about adding for root opening? Yes
3. Do you over weld all fillet welds to compensate for all cases? No. Too costly.
4. Do you have the engineer calculate and size welds for all possible joint configurations? Yes
5. Is it acceptable to apply fillets without access holes? I've never heard this question before, but I can tell you that there is absolutely no reason to add extra labor to a project by adding access holes for fillet welds. If you propose all CJP welds, your welding cost will go through the roof. With that in mind, it would probably be less expensive to just add another QC guy to your staff.
I am a Production Manager, and to me, production and quality must really be one in the same. You want to build quality into your products, not inspect it into your products. Back when I first started in the shop, I used to refer to Quality Control as Quantity Control. I have long since realized that it isn't any harder or it doesn't take any longer to do things the way they're supposed to be done. That is, by the code. Our work must meet the minimum applicable code requirements. To me, anything beyond that is overkill, and drives up the cost to produce the job. On the opposite end, anything less than that is automatic poor quality, and is rejected. Our shop guys are trained and educated to the point that they know exactly (for lack of a better phrasing) what they can get away with and what they can't. As someone once said, There's never enough time to do it right, but there's always enough time to do it twice.

By Rick Nelson Date 03-04-2005 18:01

Scott,
If I understand the code, I must assume that most fillet welds over 90 deg and any root opening must be increased in size to some extent. Maybe I'm reading more into the code than is required but after applying the code information to our fillets, some single pass welds were turning into multi pass due to single pass fillet size limitations. How can multi pass fillets on either side of a joint be cost effective vs simple prep and half the amount of deposited weld metal of CJP? What about the effect this has on the HAZ? This, of course, will affect joints of different thicknesses in different ways. Unless you are welding parts that are repeatable in size and shape with perfect fit up there can't be a cost effective way to apply fillets consistently. How is the weld size translated to welders? Shop drawings? Should not the same rules apply for fillets concerning access to both sides of the joint for the full length of that joint? I understand most people's reasoning for fillets but I think a lot is overlooked and we are taking chances by just meeting the minimum. I am enjoying this forum but need to leave for the day. We'll talk next week. Thanks to all.

By DGXL

Date 03-04-2005 18:29

I concur with Scott, the D1.1 requirments for PJP welds or skewed fillets are always adhered to, at least here on the West Coast.