Re: UT versus RT weld inspection on butt welds

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Re: UT versus RT weld inspection on butt welds
Posted by: J. Mark Davis (PID_553), E-mail: mkdavis@mindspring.com, on March 15, 2000 at 15:35 :
In Reply to: UT versus RT weld inspection on butt welds posted by : Michael Trinidad on March 02, 2000 at 13:06:
Dear Michael,
I hit the wrong key in case you get two responses from me.
I agree with the others. However, if the client has a problem with green squiggles, then perform a automated or semiautomated UT examination. Then a, b and c scans can be presented for better understanding of what is down under. Also, archivibility is a key advantage. Evaluation is more effective also.
Another consideration is digital radiography.
One technology is to scan and digitally enhance the radiographic film. My company, Digital Imaging Servcies, has scanned film and enhanced and imaged cracks like IGSCC for many of the nuclear power and petrochem plants here in the US.
Another technology is Phosphur Plates or Amorphous Silicon which are filmless technqiues. This are great for defect evaluation. Generally the human eye can see about 125 to 200 shades of gray. 4096 shades of gray can be viewed in film scanning or digital radiography.
Will you be at the Spring ASNT Conference? I am the Host Chairman and I can discuss some of these ideas with you.
Good Luck,
Mark Davis

: An ispection requires a 100% UT inspection of an 80-90mm butt weld in steel plate followed by a re-test of the same weld by 10% RT.
: The re-test by 10% RT is because the clients do not 'as always happens' trust the little green squiggly lines on the UT set or the operators.
: The only gamma source available in this country is IR192 so RT of this joint is stretching the capabilities and there are other problems, backing strip, access etc. The weld will be FCAW with multiple passes which I believe will have a common decfect of lack of inter-run fusion which RT on this thickness will be unlikely to fix.
: My suggestions to the clients in this case has been to scrap the RT and to ensure confidence in the UT operator's ability, have them perform a practcal test.
: My question is I know of codes that prefer the use of UT on thicker weldments instead of RT but does anyone recall of any papers related to the probability of detection of defects RT versus UT?
: I need as much ammunition as I can find.
:
: Kindest Regards
:
: Michael Trinidad

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: Dear Michael, : I hit the wrong key in case you get two responses from me. : I agree with the others. However, if the client has a problem with green squiggles, then perform a automated or semiautomated UT examination. Then a, b and c scans can be presented for better understanding of what is down under. Also, archivibility is a key advantage. Evaluation is more effective also. : Another consideration is digital radiography. : One technology is to scan and digitally enhance the radiographic film. My company, Digital Imaging Servcies, has scanned film and enhanced and imaged cracks like IGSCC for many of the nuclear power and petrochem plants here in the US. : Another technology is Phosphur Plates or Amorphous Silicon which are filmless technqiues. This are great for defect evaluation. Generally the human eye can see about 125 to 200 shades of gray. 4096 shades of gray can be viewed in film scanning or digital radiography. : Will you be at the Spring ASNT Conference? I am the Host Chairman and I can discuss some of these ideas with you. : Good Luck, : Mark Davis : : : An ispection requires a 100% UT inspection of an 80-90mm butt weld in steel plate followed by a re-test of the same weld by 10% RT. : : The re-test by 10% RT is because the clients do not 'as always happens' trust the little green squiggly lines on the UT set or the operators. : : The only gamma source available in this country is IR192 so RT of this joint is stretching the capabilities and there are other problems, backing strip, access etc. The weld will be FCAW with multiple passes which I believe will have a common decfect of lack of inter-run fusion which RT on this thickness will be unlikely to fix. : : My suggestions to the clients in this case has been to scrap the RT and to ensure confidence in the UT operator's ability, have them perform a practcal test. : : My question is I know of codes that prefer the use of UT on thicker weldments instead of RT but does anyone recall of any papers related to the probability of detection of defects RT versus UT? : : I need as much ammunition as I can find. : : : : Kindest Regards : : : : Michael Trinidad

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