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Ultrasonic test instrumentation and systems for scientific research, quality control inspection and production testing applications.

1030 views
00:34 Sep-11-2003
W Lee
Detection of cracks or pinholes on large diameter thin wall pipes

Can anyone let me know what types of NDT techniques/detectors are currently available for detecting cracks or pinholes on large diameter thin wall steel pipes (around 4 mm thick) for transporting liquefied natural gas? These pipes are heavily insulated.


 
05:34 Sep-12-2003
Richard Kazares
Re: Detection of cracks or pinholes on large diameter thin wall pipes If you are talking about relatively short lengths of pipe - with access to the center section, we provide a system (PipeScan) that can provide a 100% wall thickness map or using shear, provide a 100% scan looking for cracks or other defects not necessarily obvious in a straight-in UT signal.

The system is automated and currently usable from 15 through 22 inches (375 - 550 mm) inside diameter - but could easily be extended up to 1 meter.

Send an e-mail and I'll send you a photo and short vidoe of the system in operation.

Hope this is helpful


----------- Start Original Message -----------
: Can anyone let me know what types of NDT techniques/detectors are currently available for detecting cracks or pinholes on large diameter thin wall steel pipes (around 4 mm thick) for transporting liquefied natural gas? These pipes are heavily insulated.
------------ End Original Message ------------




 
07:31 Sep-12-2003

James Doyle

Consultant
Laser Techniques Company, LLC,
USA,
Joined Jan 2003
6
Re: Detection of cracks or pinholes on large diameter thin wall pipes We develop laser-based systems for similar applicaitons. They are applied from the ID however. Check our web site www.Laser-NDT.com


----------- Start Original Message -----------
: Can anyone let me know what types of NDT techniques/detectors are currently available for detecting cracks or pinholes on large diameter thin wall steel pipes (around 4 mm thick) for transporting liquefied natural gas? These pipes are heavily insulated.
------------ End Original Message ------------




 
00:21 Sep-25-2003

Daniel H.Rice Consulting Services

Consultant, Ultrasonic Evaluation of Resistance Spot Welding
Daniel H. Rice Consulting Services,
USA,
Joined Jan 2003
10
Re: Detection of cracks or pinholes on large diameter thin wall pipes ----------- Start Original Message -----------
: Can anyone let me know what types of NDT techniques/detectors are currently available for detecting cracks or pinholes on large diameter thin wall steel pipes (around 4 mm thick) for transporting liquefied natural gas? These pipes are heavily insulated.
------------ End Original Message ------------
This can be accomplished by performing the following

using Co 60 Image the pipe as you would on a elipse of a girth weld as in E94 EXCEPT the source should be perpenducular to the pipe.

Your UG should be no more than .O30 use a double load of film and .010 Pb film side intensifying screens and .010 backside intesifing screens. You may want to use a .010 intensifying screen in the middle.

use a film load of M source side and AA on the side away from the source.

Shoot a 0*,60*, and a 120* image, make sure to keep direction of flow of the pipeline consistently marked on the film.

Control your exposure to image the pipe wall use the proper IQI's.

When reading the image the image the source side will roll one way and the film side image will roll the oppisite.

"a picture is worth a 1000 Words" Ajacent to elbows will be where the corrision is the worst, as the flow accelerates and deccelerates changing direction.




 
07:33 Oct-04-2003

m.trinidad

Consultant, API 510 570 & 653
Marine Inspection Service Pty Ltd (MIS),
Australia,
Joined Jan 2003
138
Re: Detection of cracks or pinholes on large diameter thin wall pipes There are several LRUT (Long Range UT) devices on the market which may be of some use.

The defect has got to be over a particular percentage of cross wall area to be detected which for some perculiar reason a lot of people believe LRUT cannot find pin holes. However LRUT should not be disputed out of hand as my personal experience is that yes the pit may be a pin hole on the outside but on the inside, with associated corrosion, pitting etc.

Cracking is another problem as orientation is going to be a big factor and transverse to the pipe is best. I have seen once experimentality and once in the field where cracks have been detected and both times they were rather large.

Many other factors to be considered similar to ET "many known and unknown variables" to contend with that affect the sensitivity but most likely worth you effort to get a company in to do a trial section.

Kindest Regards

Mike Trinidad
----------- Start Original Message -----------
: : Can anyone let me know what types of NDT techniques/detectors are currently available for detecting cracks or pinholes on large diameter thin wall steel pipes (around 4 mm thick) for transporting liquefied natural gas? These pipes are heavily insulated.
: This can be accomplished by performing the following
: using Co 60 Image the pipe as you would on a elipse of a girth weld as in E94 EXCEPT the source should be perpenducular to the pipe.
: Your UG should be no more than .O30 use a double load of film and .010 Pb film side intensifying screens and .010 backside intesifing screens. You may want to use a .010 intensifying screen in the middle.
: use a film load of M source side and AA on the side away from the source.
: Shoot a 0*,60*, and a 120* image, make sure to keep direction of flow of the pipeline consistently marked on the film.
: Control your exposure to image the pipe wall use the proper IQI's.
: When reading the image the image the source side will roll one way and the film side image will roll the oppisite.
: "a picture is worth a 1000 Words" Ajacent to elbows will be where the corrision is the worst, as the flow accelerates and deccelerates changing direction.
------------ End Original Message ------------




 


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