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427 views
07:47 May-06-1997
Michael Hnytka
Mechanised UT on Girth Weld

I'm currently working with Rivest testing and observed the test RTD was performing on the 42" pipeline for TCPL in Manitoba. I was wondering if they determine what the background noise they were receiving was from? And, I was also interested if they had any problems with scanning both sides of a transition weld? Problems being thickness changes, material changes and weld profile changes?


 
01:25 May-09-1997

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1197
Re: Mechanised UT on Girth Weld : I'm currently working with Rivest testing and observed the test RTD was performing on the 42" pipeline for TCPL in Manitoba. I was wondering if they determine what the background noise they were receiving was from? And, I was also interested if they had any problems with scanning both sides of a transition weld? Problems being thickness changes, material changes and weld profile changes?


Michael:
The "background noise" was found in the initial setup
and was associated with a problem in probe/wiring .

As for transition welds you mean the weld that joins a
heavy wall pipe to a light wall pipe. The transition
is made by counterboring the heavywall pipe to match
the lightwall pipe thickness. The counterbore extends
for a distance of about 50-60mm which ensures any skip
point will occur at the same thickness as the
light wall pipe on which the array was calibrated.

The matching of thickness by the counterbore
ensures the weld profile is maintained.

The material difference we are primarily concerned
with is shear velocity variation between manufacturers.
In the technique used only one probe was over
70 degrees. Only this beam might be adversely affected.
For the 60 degree probes the angle changes that might result
due to velocity variation would not likely be more
than 2 degrees. The 70 degree probe used in the
technique was used in the root area which was also
inspected using a 60° and TOFD.


Sorry about the dealy in response, I got called
out of town with no access to the internet.

ED



 


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