WPS needed for welding E71T-1 OVER E7018?

By pipewelder_1999 (****)

Date 05-27-2008 17:16

Hinkdog,

Weldome to the forum.

AWS D1.1 Para 3.6.1 Combination of WPSs. may provide some guidance.

I think that covers it but I may be amiss. Do not forget that the engineer may very well sppecify additional requirements above and beyond AWS D1.1

Gerald
www.weldingdata.com

By HinkDog411 Date 05-27-2008 17:33

Thank you Gerald, I appreciate your help. I had read that section, but what was asked by the engineer (as it was told to me) was for one that applied to welding over the tacks, therefore asking for a new WPS, not a combination of two.

Again, I can't seem to find criteria for this in D1.1. I can write up a WPQR for it, have a test plate(s) made, but what to what specific requirements am I to have them tested? That's the part that stumps me. What specifications(criteria) am I testing to if I go through the WPQR process? What do I tell the testing firm I am going to have do the testing? I can't find anything that specifically applies to this situation. I am being asked to look into this o that we can be prepared in the event of being asked for one.

Thanks again for getting back to me Gerald, and for the welcome. I am still a little nervous when going outside the lines on things.

By pipewelder_1999 (****)

Date 05-27-2008 17:47 Edited 05-27-2008 17:51

The allowance to use multiple WPS's allows you to weld up a joint with one WPS (E7018) and then Follow up with another. (FCAW) . There is no distinction regarding how much of one joint needs to be welded up. Tacks, root, fill only etc.

It is my opinion that the referenced paragraph is the one that applies to bthe situation. In addition in para 5.18.1 it is addressed that tack welds shall meet the requirements for the final weld. Could 7018 be used for the final weld ? If yest then 7018 tacks are OK. If 7018 is not OK then 7018 tacks would have to be removed before subsequent welding.

Lets look at the SAW process, what process can be used to tack thos welds? Any. Which is good since tacking with SAW would not be very practical.

Thats my view and is subject to change provided further guidance is provided from others. There is not a practical reason to prohibit this practice. An example of a practicle reason to prohibit the practice could be the use of some self shielded FCAW wires. Some of thise do NOT lend them selves to being welded over with other processes.

Have a good day

Gerald Austin
Iuka, MS

By HinkDog411 Date 05-27-2008 18:16

Gerald......you da man!

I believe you are correct on the use of two processes, one following the other. I will pass this along to the "powers-that-be" here and see where we go with it. I believe you are spot-on with that assessment and I appreciate it. Sometimes I need a little reminder about what's in the book.

Again, I appreciate your info and help!

You have a great day too!

By Kix

Date 05-27-2008 17:26

What code are you supposed to abide to on this project? If you don't mind me asking, why would to want to tack with E7018 electrodes in the first place? It would be much faster and consistent to tack with the FCAW method you're going to end up using anyway. E7018 tacks = bad arc starts after your first start, unless your tacks are long enough to use a whole electrode. If your flux on the end of the rod flakes a bit after you've beaten it against the part trying to get it to restart for your next tack, porosity will likely occur and if not ground all the way out, it will move into the next weld layer. When you specify a code to reference, you will get some very good help!

By HinkDog411 Date 05-27-2008 17:38

Kix,

Unfortuantely, I am not sure WHAT is being asked, as it was by another company here in town that was asked. I was just told of this situation and my boss asked me to look into it to be prepared BEFORE we get asked (if we get asked). He is a business major-type guy and doesn't quite get the "I need the specifics before I can write it" thing that is what we do.

I am assuming (yes, I know the old joke about assuming), that the code is D1.1, as that is the predominant codecalled out in projects here.

As for using 7018 for tacking it is very common here and efficient. We can't afford to have (I'm told) that many welding machines for dual shield in our shop. Not my decision, as I am not in charge of the actual economics of the company.

I apprecate the info and help.

Thanks.

By hogan

Date 05-27-2008 18:11

you are having difficulty with this because this type of intermixing of fillers has been an issue with FEMA. look to FEMA 350

By ctacker (****)

Date 05-28-2008 00:11

I've worked alot of structural shops in the phoenix area and I can tell you that EVERYONE of the ones I worked at(big & small) the fitters tack with SMAW and the welding is done with FCAW-g. if you pinch the end of a rod and twist with your gloved fingers you can get a good start each time!