Qualifying a procedure.

Date 07-30-2011 11:37 Edited 07-30-2011 12:32

Good morning;
What am I doing here on a Saturday??? I guess I should be more careful what I volunteer for. The question I have is this: We have to qualify a new procedure under ASME Section IX. The previous PQR showed a groove weld with backing. 1g Rotated positon. My boss asked if the following joint detail would be considered as such. It would be socket joint with bevels machined on both ends of the pipe. The pipe itself would act as backing material. I have performed a test like this before but I believe it may have been for Sub Arc and it was going to be RT'd. We have to perform tensiles, bends, charpys, hardness,macros, and LP. This would be for PJP weld qualification as most everything we weld is a socket weld. Very little open roots. If I can figure out how to attach a sketch on here, I will do so. My boss has sent the question to the weld engineer. Thought I would pose the question to the more learned folks in here. Thanks for your time.

Have a good day;
Matt

By 803056

Date 07-30-2011 19:27

We need a sketch.

A socket joint requires a fillet weld around the joint. There is no bevel involved.

A groove weld qualifies fillet welds per ASME Section IX.

Al

By unclematt (***)

Date 08-01-2011 10:34 Edited 08-01-2011 10:43

Thank you Al for your response. I have created a sketch but I am unable to resize to get it posted on the forum. If I may try to explain in words...... 1/2" wall pipe with two 30 degree bevels 3/8" deep........one bevel starting at the end of the pipe with the other starting 1/4" to 3/8" back from the end. On the ID of the pipe where the bevel starts at the end, machine a 1/8th inch recess 1/4" to 3/8" deep to accept the other pipe..... I suppose a tongue and groove description would have been a better choice of words in my original post. May I email you a sketch?

Thanks;
Matt

By js55

Date 08-01-2011 13:24

I don't understand the question.

By unclematt (***)

Date 08-01-2011 14:49 Edited 08-01-2011 15:14

Hello js55;
I may have not explained it very well. I guess a simplified way to put it is: When performimg a weld procedure qualification test using a tongue and groove weld joint configuration, could you qualify the procedure as a groove weld with backing; using the coupon itself as backing? Would you know how I can resize a "Windows paint program" sketch small enough to submit it here to the forum?

Thanks;
Matt

By waccobird (****)

Date 08-01-2011 15:22 Edited 08-02-2011 16:29

unclematt

send it to me I will see what I can do about re sizing.

waccobird@gmail.com
Attached is the sketch from unclematt

Attachment: Doc1.pdf (81k)

By unclematt (***)

Date 08-06-2011 13:05

waccobird;
Thank you for re-sizing the sketch for placement here on the forum. After seeing the sketch, did you have any thoughts as to if this would be considered a groove weld with backing for procedure qualification? I am administering another procedure qualification test using 80KSi 4140 with an open root. I am considering doing away with the backing for the other test because, as js55 stated, backing is not an essential variable in procedure qualification. This will qualify the procedure for any and all welds we have come our way in this particular
material. The reason we are re-qualifying is because the exsisting joint configuration does not allow adequate axcess to the joint root with the already qualified SMAW procedure. With using the 4140 140KSI material, we have had several rejects because of cracking. We have found that running a GTAW root with SMAW out results in a weld that has greater root penetration and eliminates the cracking problem. I am very appreciative of your your help and any advice that you can send my way. Have a good day.

Matt

P.S. Could you enlighten me as to how you were able to resize the sketch? I am not as tech savvy as I should be I suppose. Thanks again.

By bozaktwo1 (***)

Date 08-08-2011 17:28

Wow. My first thought is, PJP. Definitely a groove weld, but I wouldn't call that with backing. More like a modified lap joint, or a tongue in groove. Where are your cracks propagating from?

By unclematt (***)

Date 08-08-2011 17:43

bozaktwo1;
The weld foreman seems to think it is originating from the root. I submit it is, because of the joint design, the lack of penetration to the root is causing a stress riser. The material and the rate of cooling after the weld is also a factor, I believe. These welds are for placing a key over a window in a piece of tube. We have decided to do away with the backing a perform an open root test. Thanks for your reply to this post. Have a good one.

Matt

By jwright650 (*****)

Date 08-08-2011 17:44

Looks like PJP to me also...I can't see how you could get CJP due to the root/backing configuration.

Interesting joint to say the least....keep us up to date with how this progresses.

By 99205

Date 08-08-2011 18:20

Maybe an Engineer would know better, but it seems to me that there would be some unusual stress development in the root pass of that joint configuration.

By js55

Date 08-01-2011 15:24

matt,
I don't know what a tongue and groove joint is. I can't help you with paint. But keep in mind under ASME backing is not an essential variable for procedure qualification. It is for performance quals though.

By unclematt (***)

Date 08-01-2011 15:28

Thank you js55 and waccobird for your responses. I will email the sketch to you, waccobird.

Have a good one;
Matt