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Up Topic Welding Industry / Inspection & Qualification / Conflicting RT interpretation
- - By Superflux (****) Date 01-11-2015 14:08
Can RT repairs be rejected if the technicians find new defects outside of the repair that was not "caught" on the original film?
Film #1 was rejected due to lack of fusion in the root. Repair shot indicates poor tie-in and then is also being flagged for repair of porosity in another section of the weld. I really have no control over the RT crew so I have no vested interest in this. But I've never run into this issue before.
Just curious... Thank goodness.
Any of you ever run into this problem?
Parent - - By thirdeye (***) Date 01-23-2015 20:55
If I'm reading this correctly the initial weld had an area (let's call it view 0-1) that contained rejectable IF which was marked for repair. Then later in time, another view on the same weld (let's call this one view 2-3) which was accepted following the initial review, is now being rejected for porosity.

1.  Was the initial set of films reviewed again, maybe by the customers auditor and he/she overruled the RT technicians initial interpretation?  This happens on occasion.

2.  Maybe the RT technician was reviewing the initial rejectable area  in view 0-1 to compare it with the "repaired" area, and happened to notice they overlooked the porosity in the 2-3 view, (or made an inaccurate measurement) and realized it is in fact rejectable.

3. Is it policy to radiograph the entire weld again after repair, verses only the particular view which was rejected?  If so, a slight change in the placement of the source can sometimes make an indication appear differently with respect to length or diameter, and could display a length which is now rejectable.  For example, because of it's orientation it's common in cases of a "suspect crack" to shoot a couple additional radiographs, each one about 10° off the typical placement of the source used in the initial exposure.... many times one of the additional shots will display the crack much better than the initial radiograph.  Likewise, with a DWE/SWV technique the radiographic image of a gas pocket or cluster porosity, or slag inclusion may appear differently if it is located near the end of a radiograph than if the same indication is located at the center of the radiograph.
Parent - By Superflux (****) Date 01-23-2015 23:13
Third eye,
"image of a gas pocket or cluster porosity, or slag inclusion may appear differently if it is located near the end of a radiograph than if the same indication is located at the center of the radiograph."
I think this is the cause.
As I said, I don't even have the duty to review or even see the film. It's totally off my plate.
I only seek a better understanding and try not to be judgemental.
Tanks for your clarification,
- - By 803056 (*****) Date 01-11-2015 16:31
It is sometimes referred to as inadvertent RT. Once a defective weld is identified, it must be addressed.

Al
Parent - - By JTMcC (***) Date 01-12-2015 03:06 Edited 01-12-2015 03:09
In my experience, yes. Same with xray and visual.
While working repairs I've seen several instances where additional repairs were called, and completed.
J

edit: sorry, thought you were talking ut, seen this many times with rt. Defect is a defect right, gotta get fixed by sombuddy : )
The rt auditer finds things the original interpreter missed, there ya go. Just my take.
Parent - - By Superflux (****) Date 01-12-2015 11:43
I just do not wish to be guilty of "Over Inspection".
That and I am trying to understand (be sympathetic?) the "competency" of the RT crew.
For instance, now we are on R3 and a couple of R4s.
The RT interpreter just keeps finding "more stuff"...
Parent - By 803056 (*****) Date 01-12-2015 13:38
The welding contractor should have the opportunity to review all the film. If the contractor providing the RT services is changing the technique or changing the location of the film, the welding contractor has a legitimate complaint.

Best regards - Al
Parent - - By js55 (*****) Date 01-12-2015 16:47
This should be a rare occurrence. If this is happening on a regular basis you have a quality control problem with your RT vendor.
And R4???
I'd be having a sit down with my vendor and asking WTF!!!
And depending upon spec and Code you do not have to shoot the whole weld again.
Parent - By js55 (*****) Date 01-12-2015 16:49
Besides I can see planar defects (fusion) popping up in new views but it should be very rare for rounded indications (slag or porosity) to suddenly pop up.
Parent - By 46.00 (****) Date 01-12-2015 19:33
No No No! unless your welders are putting defects into the repaired weld, the Interpreter shouldn't be finding more defects!
Parent - - By TimGary (****) Date 01-12-2015 20:11
Lots of things can cause situations like this.
In most applications, a limited amount of porosity, especially internal rounded, is acceptable.
To determine acceptability, there are a lot of variables, like:
Measure the diameter of each indication and compute a total volume per inch of weld.
Determine if any are "Tailed".
Measure to see if any one particular indication is too large.
Disregard indications below are certain diameter.
etc etc.

When you consider that separate shots most likely are taken at slightly different angles, which can change the view, and that quality of exposures vary, and that different Interpreters have different opinions, skill levels and work ethic, it's easy to see how this happens.

Bottom line is that if a reject is found, it must be corrected, regardless on which round of shots is being done.

Tim
Parent - - By Superflux (****) Date 01-18-2015 01:13 Edited 01-18-2015 03:47
Thanks to everyone for all the help and suggestions.
I am lucky in that I'm not the manager over RT (WHEW!!! Big relief there).
Also set a new record here (of dubious notoriety) as this is the first job I've ever been on that had a 100% RT failure rate.
4 months and we have 140 welds now accepted.
Parent - By 803056 (*****) Date 01-18-2015 01:35
Ouch!

Al
Parent - - By welderbrent (*****) Date 01-18-2015 11:44
100%!  Wow, nothing quite like being a complete success at your job,  :lol: :confused:

I agree with Al,  OUCH!  I'll bet someone was not happy with those percentages.

But, sometimes we have to be knocked down to remember how to do things right.  Welders get in habits of cutting corners because not every job has high expectations and then have to rework their technique, procedure, and skills until they get it right. 

He Is In Control, Have a Great Day,  Brent
Parent - - By 803056 (*****) Date 01-19-2015 02:51
As I say, the less they know, the more we make.

Their pain is our profit. Our task is to ease their pain. The more they hurt, the more we make.

We are their cure. Help is just an e-mail away!

Best regards - Al
Parent - - By Superflux (****) Date 01-20-2015 13:19 Edited 01-20-2015 13:49
Since my arrival (10 working days ago on the ROW), we've averaged 3 completed welds per day. This includes the 11 RT repairs.
There are just over 2,000 welds on this line. They told me 6-8 months here. Somehow the math aint quite working out???!!!
AND it is a 4 day work week to boot! I hope my Daughters come visit me cuz otherwise I aint gonna see them for Looooonnnngggg time to come.
The good news is; The last figures I ran had us up to 87% ACCEPTANCE. This of course I attribute to my Superior and superhuman Quality control powers...
Progress and improvement. What  more can you ask for?
Parent - - By Superflux (****) Date 01-20-2015 13:39 Edited 01-20-2015 13:46
MATH
1 mile = 5280 feet divided by 40' sticks of pipe = 132 welds, X's 17 miles = 2244 welds divide by 3 per day = 748 days, divide by 4 (days/work week) = 187 WEEKS!!!
OMG, I need more welders. Not sure how much of this tropical paradise I can handle...
Rumor is that my 3 welders make between 12 and 18 bucks an hour which is excellent "local" pay for skilled labor (if ya wanna call it that!).
So PLEASE don't bother asking me for contact info to help you get on this gig.
Parent - By welderbrent (*****) Date 01-20-2015 15:13
What, you sayin' it wouldn't be worth it just for the experience of working around you and in a tropical paradise to boot?? :lol:

He Is In Control, Have A Great Day,  Brent
Parent - - By aevald (*****) Date 01-20-2015 15:15
I don't know John, a 4 day work week in paradise, even with the low pay it might just be a good gig anyway. Just all depends on how you view life. Best regards, Allan
Parent - By Superflux (****) Date 01-21-2015 11:29
Allan,
They hire locals because the hands don't get per diem or travel. Apparently this is how they can financially justify this world class RT failure rate.
"Just all depends on how you view life."
Well, if you set your standards low enough, you can be content with anything.

I DO manage to stumble onto some doozies though.
Back in 2008, I was on a refinery where we had a 316SS peroxide line with a Zero tungsten inclusion clause in the specs. That first run of RTs had an 87% fail rate after about 60 shots. And I thought then "Surely this will be my all time record"!
Little did I know...
The bad news is; I'll never have another gig with a worse number.
Just prior to my arrival, there was one joint in particular (can't really call it a weld BECAUSE!) they went to R2, FAILED! Then the weld was cut out and went to R2 again before acceptance.
Not every weld here was an RT failure, but a few of the examples such as mentioned actually drove the numbers to an even 100%!
This kinda stuff keeps me well entertained.
- - By Dualie (***) Date 01-21-2015 04:42
whats the fishing like?   Im listening...
Parent - By Superflux (****) Date 01-21-2015 11:15
Dualie,

Haven't dropped a line in the water yet. Only been snorkelling a couple of times due to we keep getting hammered with tropical depressions. The last one skirted by us, and went to the Philippines cutting the Pope's trip short.
Been here 19 days and it has rained 17 of them. Always on my days off!
One local offered to take me scuba diving to an outer island. In broken English he said; "My friend, he have big boat. 18 maybe 20 foot big". Hmmmmmmm... Can't wait to take on the high seas in that one. I have been boat wrecked on a desert island before in the Texas Gulf.
I'll start a topic in the OTB&G with fotos soon.
Up Topic Welding Industry / Inspection & Qualification / Conflicting RT interpretation

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