Questions on D1.1 Prequalified joints

Date 10-02-2005 01:48

Hi fellow forum members.

These questions are to help me have a better understanding of the application of Figures 3.3 and 3.4 . The version of D1.1 I am using is the 2002 version.

1. Can a TC-U4a with groove angle of 30 degrees be detailed on drawings to show a root opening of 3/8 + 1/16 = 7/16 inch, which will then permit the actual root opening to be as wide as 7/16 + 1/4 = 11/16 inch? In other words can detailed and fit-up tolerances be added? Section 13.13.1 suggests that they can.

2. According to D1.1 Section 3.11.1, "groove preparations detailed for prequalified SMAW joints may be used for prequalified GMAW or FCAW". Then there is Figures 3.3 and 3.4 note 5 to consider.

Does this mean GMAW globular transfer mode can be used on B-P1a? If so, what about allowed welding positions? For SMAW, Figure 3.3 indicates "All".

By jwright650 (*****)

Date 10-03-2005 11:51

I'm apologizing in advance for the quickee reply.

#1 yes, you can add up and consider all of the tolerances both detailed and fit-up.

#2 yes, I read 3.13.1 to say that it is permissible.

#3 I think all positions may be a stretch if your wire isn't recommended for all positions.

John Wright

By henri

Date 10-03-2005 14:34

Thanks a lot John.

I have one more question if you do not mind.

Plan indicates an arrow-side all around PJP bevel groove weld with 1/2 inch depth of bevel will be used to join 4-3/4 inch thick base plate to bottom of W 14 x 730 column. Material is A 992 and FCAW-S will be used.

Is there any prequalified joint for this?

By jwright650 (*****)

Date 10-03-2005 14:55

Have you looked at the BTC-P4-GF? You can bevel the column shaft flanges and web to get your 1/2 depth of bevel and that would indicate a required weld size of 1/2 (S min.), if performed in F, or H positions which is within Table 3.4's requirements for the thickness of the column shaft's web and flanges. I'm curious why you want to use a self-shielded Flux Cored wire. Be careful of the types of self-shielded wire you use, some aren't classified for multipass, and some don't meet minimum charpy requirements. Is this weld is being done in a shop or in the field?
John Wright

By henri

Date 10-04-2005 00:42

Thanks for being so helpful.

I looked at the BTC-P4-GF. Can this be used for a PJP bevel all around the perimeter of the column at the base? For an all-around PJP bevel groove weld, apart from flange tips, all other locations will be double bevel, no? What about the BTC-P5-GF for the perimeter except at flange tips? And then for flange tips use the BTC-P4-GF?

Lincoln NR-233 wire will be used..it's tough enough. Fabrication will be done in large open structure under roof ....exposed to wind draft.

FYI I do not work for the fabricator and am no expert on welding. I know the owners and they wanted to know what my opinion was because the QC fellow who was responsible for developing their WPSs recently left. I understand they'll be hiring a replacement very soon. Meanwhile they have this little problem. My initial thinking was that a qualified WPS was required but your response is moving me in the direction of recommending a prequalified WPS.

By jwright650 (*****)

Date 10-04-2005 15:10

Will your advice to the fabricator get sent out to the EOR for approval?
The original weld symbol sounds like something that wasn't thought out very well by the designer, and I realized this after I thought about your situation some and you mentioned the BTC-P5. Maybe you could submit a detail of the joint showing the BTC-P5 along both flanges and the BTC-P4 along the web. Similar to this link...
http://img.photobucket.com/albums/v345/jwright650/welding%20pictures/Col2BPlate.jpg

Submit your written WPS and instructions that will be given to the fitter/welder so the EOR will have a good understanding of what you are proposing. To distinguish the flange welds from the web, use rat holes so that the flange welds can be continuous for the width of the flange. You should grind smooth and MT or PT around the rat holes before welding, due to the size of the column being in the Group 4 and 5 category(5.17.2). BTW, I wouldn't weld at the toes of the flanges. Along the flange width and the web is normally all that is required.
John Wright (feel free to email me if you need to jwright650@aol.com )

By henri

Date 10-04-2005 17:55

John you are a true guru. This information is very valuable. Thanks ever so much.

Yes, the SEOR will review the WPS they submit, run the structural cals to see if it works, stamp "no exceptions taken" if satisfied, then make a revision which will have to be approved by plan check. Many SEORs out here will not stamp "approved" unless a bldg department requires them to do so; I guess for liability reasons.