CJP (TS to TS) WPS and Welder Qual

By John P Sullivan Date 08-16-2007 19:59

Could someone verify my conclusion interpreting AWS D1.1
We are looking at a job (for a company that already has a contract) which includes CJP weld joints with backer plate
TS 6X12X1/2 welding to TS 6X12X1/2 sloping Tee configuration (column to sloped roof beam 4.6/12 slope) using FCAW. The Contract Drawing shows weld symbol for "flare-bevel with backer all around" also 100% UT or RT is required on all CJP joints. They also want all welds to be prequalified

I believe weld symbol is wrong as flare-bevel would only apply to two sides of column
and there is no prequalified weld joint for this with backer
and we would have to qualify the joint.
I also believe welders need to be qualified in 6GR position T-Y-K connection, with same tube used in contract?
Do engineers realize what they are asking for? I think a continuous backer, weld prep and ability to pass UT would be near impossible.
Sorry for the long post but it took a long time to come to my conclusions and I would be interested in your expert opinions. Am I making a mountain out of a molehill? How would you make a backer for these same size tube? (as the backer has to extend lower on the flare bevel sides)

By James Ashe Date 08-23-2007 17:28

I ran into a similar situation not long ago. Am new at this and hope others will address this question. This is what I did. Read 3.13 specifically 3.13.3(1); 3.13.4; 3.13.4.1 now go to table 3.6 and then check Fig. 3.8 Detail B. I'm assuming the roof beams are sitting on top of the columns. Your slope, if I did the math correctly, indicates a 21degree cut. I believe the way I read these sections that this is a prequalified joint configuration. For my situation I cut flat bar and used round bar for the inside corners to match the radius of the tubing. You can cut the ends of the flat bar at same degree cut as the columns so they will fit in nicely. Now follow fit up from table 3.6 and fig. 3.8. Their are a lot of smart people that come to this site and I hope they will comment also. You are right about the welders not being qualified to weld this, they do need to qualify by the 6gr position for T-Y-K connection per Table 4.10. Again, hope others will comment on your question.

By dschlotz (***)

Date 08-29-2007 12:16 Edited 08-29-2007 12:25

As far as the backing goes, this is what I do in this configuration. I use a flat plate, 1/2" thick, cut to fit the inside of the tube steel. It is just like capping the tube only the plug goes on the inside with 1/16" maximum gap anywhere. I miter the ends and radius the corners, of this plate, at the same angle and inside radius as the joint configuration and insert this plug leaving enough of it sticking out to achieve the required root opening. Because there is only one piece of plate my backing is continuous as required by code.

I would just draw it up as I described and float it as a CJP groove weld (Single "Bevel") with backing and let them come back with a response.

Click on my name at the top of the post to reveal my email address if you wish to contact me.

Dennis

I just read anoither post about this same subject. http://www.aws.org/cgi-bin/mwf/topic_show.pl?tid=12704#fp

By swsweld (****)

Date 08-30-2007 02:14

http://www.robvon.com/ under products click squings. They can make other sizes that are not on the chart. Don't know if this will work in your situation with the slope. Hope it works.

By dschlotz (***)

Date 09-01-2007 22:08

These backups are not acceptable in full pen situations. They are not continuous. The back up must be continuous one piece.

By ctacker (****)

Date 09-02-2007 05:14

D.1.1 2.2.1, 2.2.3 and 2.2.5 should make the engineer tell you how to do it!

By swsweld (****)

Date 09-02-2007 23:38

It may be more trouble than it is worth but it wouldn't take much to weld, backgrind and weld to make the split a continuous backing bar.

I'm not trying to push these products. No affiliation. Just a thought.

By ctacker (****)

Date 09-03-2007 01:45

I left a post here saying just that!

would only take about 15 minutes a splice if you have a shear and bender close by,smaller tubes would require fillet inside corner first then grind to weld and fill from outside
http://www.aws.org/cgi-bin/mwf/topic_show.pl?tid=12704#pid69310

By swsweld (****)

Date 09-03-2007 06:13

Good to know I wasn't the only one. Wasn't sure if I was on the right path on that one.