 11382 views |
 Technical Discussions |
| nathan
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nathan
|  09:41 Feb-07-2008
RT film interpretation can we see the oxidation image(oxidation due to lack of purging in SS welding ) in the readiographic film.
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| chris s
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chris s
| 03:19 Feb-07-2008
Re: RT film interpretation ----------- Start Original Message -----------
: can we see the oxidation image(oxidation due to lack of purging in SS welding ) in the readiographic film.
------------ End Original Message ------------i believe that you would be able to see evidence of no purge in a radiograph
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|  burhanudin sudharmin
Engineering, Reliability and Integrity Eng
Shell Malaysia Trading, Malaysia, Joined Jan 2008,  54 |
burhanudin sudharmin
Engineering, Reliability and Integrity Eng
Shell Malaysia Trading,
Malaysia,
Joined Jan 2008
54
| 05:40 Feb-08-2008
Re: RT film interpretation A lot of things can be observed from radiographic films. The technique is a penetrating eye. However, the image on radiographic films are based on difference in material densities and amount of radiation that passes through, interpretation of the image is quite subjective with the exception of proven codes and standards defect sizing. I personally have seen objects and debris such as sand being projected onto radigraphic films due to the carelessness of the repair crew. My advice for your case, is to have a test piece of a non purging SS welding and see how it looks like on radiography.------ Start Original Message -----------
: can we see the oxidation image(oxidation due to lack of purging in SS welding ) in the readiographic film.
------------ End Original Message ------------
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| John Brunk
Engineering, NDT Level III
Self employed, part-time, USA, Joined Oct 1999, 162 |
John Brunk
Engineering, NDT Level III
Self employed, part-time,
USA,
Joined Oct 1999
162
| 07:26 Feb-08-2008
Re: RT film interpretation ----------- Start Original Message -----------
: A lot of things can be observed from radiographic films. The technique is a penetrating eye. However, the image on radiographic films are based on difference in material densities and amount of radiation that passes through, interpretation of the image is quite subjective with the exception of proven codes and standards defect sizing. I personally have seen objects and debris such as sand being projected onto radigraphic films due to the carelessness of the repair crew. My advice for your case, is to have a test piece of a non purging SS welding and see how it looks like on radiography.
: ------ Start Original Message -----------
: : can we see the oxidation image(oxidation due to lack of purging in SS welding ) in the readiographic film.
------------ End Original Message ------------
I have had several experiences of performing both x-ray and borescope inspection of stainless steel welds. For applications such as food machinery and sterile water systems there can be rejectable ID surface conditions from incomplete or lack of purge that could never be imaged with high sensitivity radiography. Other industry requirements are not nearly so restrictive. There are other situations where gross oxidation from lack of purge would be quite evident on a radiograph. The ability to detect a certain extent of this problem depends a lot on the section thickness, double or single wall exposure, x-ray or isotope. The accept/reject criteria, material thickness, and available equipment all have to be considered. Sometimes there is no substitute for a borescope.John Brunk
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| fereidoon zolfaghari
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fereidoon zolfaghari
| 07:31 Feb-12-2008
Re: RT film interpretation long time back under a perfect gamma radiography exposure time i could read letters such as kodak and fogi on the cover sheet of a fine graine coarse radiography film.u may read oxidation from RT film if u expose a fine graine film ,set for best geometric condition,wash up with standard procedure. by trial and error u can expose a field case together with a sample case under perfect exposure and process condition with fine IQI also. comparing the final film u may infer about ur parameter.
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| Cjhumane
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Cjhumane
| 09:00 Mar-03-2008
Re: RT film interpretation ----------- Start Original Message -----------
: long time back under a perfect gamma radiography exposure time i could read letters such as kodak and fogi on the cover sheet of a fine graine coarse radiography film.
: u may read oxidation from RT film if u expose a fine graine film ,set for best geometric condition,wash up with standard procedure.
: by trial and error u can expose a field case together with a sample case under perfect exposure and process condition with fine IQI also.
: comparing the final film u may infer about ur parameter.
------------ End Original Message ------------Can i ask a film interpretation procedure as Im new in the NDT Industry? Pls..
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| jason
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jason
| 05:18 Mar-14-2008
Re: RT film interpretation ----------- Start Original Message -----------
: can we see the oxidation image(oxidation due to lack of purging in SS welding ) in the readiographic film.
------------ End Original Message ------------Absolutely. Some people refer to it as a sugared root. The biggest problem isn't finding it, it's what to do with it. Most codes don't address it so if there isn't lack of fusion or other defects radiographers generally note it on the report and accept it. Another approach is to reject the weld on the basis that it doesn't meet the welding procedure requirements but that isn't a call a radiographer will make unless it's agreed with the inspector/QA rep. Cheers
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| Bill Kiesel
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Bill Kiesel
| 02:04 Mar-14-2008
Re: RT film interpretation ----------- Start Original Message -----------
: : can we see the oxidation image(oxidation due to lack of purging in SS welding ) in the readiographic film.
: Absolutely. Some people refer to it as a sugared root. The biggest problem isn't finding it, it's what to do with it. Most codes don't address it so if there isn't lack of fusion or other defects radiographers generally note it on the report and accept it. Another approach is to reject the weld on the basis that it doesn't meet the welding procedure requirements but that isn't a call a radiographer will make unless it's agreed with the inspector/QA rep.
: Cheers
------------ End Original Message ------------We perform raidography on thin walled sst tubing and find oxidation occasionally. It appears as a more-dense weld with a mottled look. On visual verification it will have a grey almost crystalline apperance. We consider it a rejectable defect since it is a indcation of a non-controlled welding process.
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| azmi
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azmi
| 01:16 Aug-26-2008
Re: RT film interpretation ----------- Start Original Message -----------
: : : can we see the oxidation image(oxidation due to lack of purging in SS welding ) in the readiographic film.
: : Absolutely. Some people refer to it as a sugared root. The biggest problem isn't finding it, it's what to do with it. Most codes don't address it so if there isn't lack of fusion or other defects radiographers generally note it on the report and accept it. Another approach is to reject the weld on the basis that it doesn't meet the welding procedure requirements but that isn't a call a radiographer will make unless it's agreed with the inspector/QA rep.
: : Cheers
: We perform raidography on thin walled sst tubing and find oxidation occasionally. It appears as a more-dense weld with a mottled look. On visual verification it will have a grey almost crystalline apperance. We consider it a rejectable defect since it is a indcation of a non-controlled welding process.
------------ End Original Message ------------
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| Fijo Antony
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Fijo Antony
| 18:47 Aug-14-2013
Re: RT film interpretation In Reply to azmi at 01:16 Aug-26-2008 .
We are in confusion , Today we saw some indication on RT film. We will cut that weld and we will see.... |
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| Gerald R. Reams
Engineering,
Industry, USA, Joined Aug 2012, 182 |
| 01:24 Aug-15-2013
Re: RT film interpretation In Reply to azmi at 01:16 Aug-26-2008 .
The lack of adequate purging gas at the root of the weld causes oxygen and other impurities to react with the molten/hot metal on the pipe or tube ID. This discontinuity is commonly known as "sugaring the root." It is apparent through discoloration of the weld root and can be seen visually or with a videoscope. The larger or more severe indications will have a sugared appearance and can appear crackled.
Whenever I have encountered sugaring of the root, I have rejected that area of the weld. In addition to the acceptance criteria of the weld, a visual examination is usually required and I use the visual acceptance criteria. Even though x-rays can see through walls, it is still a visual aid.
This has been my experience and opinion in the nuclear, utility, and petrochemical industries. |
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| Jon Wallis
NDT Inspector, -
Netherlands, Joined Feb 2010, 626 |
| 08:00 Aug-15-2013
Re: RT film interpretation In Reply to Gerald R. Reams at 01:24 Aug-15-2013 .
In Germany this is colloquially known as 'cauliflower' effect due to its appearance on the radiograph. It can also appear in carbon steel welds such as P9-1.
This defect is rejectable according to visual standards but not covered by RT interpretation standards and as such we also reject the welds. |
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| srinivasan
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srinivasan
| 21:00 May-14-2015
Re: RT film interpretation In Reply to chris s at 03:19 Feb-07-2008 .
can we see the oxidation image(oxidation due to lack of purging in SS welding ) in the readiographic film |
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| Jon Wallis
NDT Inspector, -
Netherlands, Joined Feb 2010, 626 |
| 12:17 May-15-2015
Re: RT film interpretation In Reply to srinivasan at 21:00 May-14-2015 .
Yes, read the previous answers.... |
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