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VOGT Ultrasonics GmbH
non-destructive testing, services, training, ultrasonic systems, immersion and squirter inspection systems, PROline, digital radiology

931 views
01:56 Mar-20-2004

Abdulhamid Al-Akel

Engineering
Saudi Arabia,
Joined Mar 2003
2
U/G condition Assessment

We have Oily water drain U/G lines that were found severly corroded and started leaking contaminating soil. These lines are C.S and externaly PE wraped. Please advise on available NDT methods that can be utilized to assess the condition of these lines without excavation.


 
07:12 Mar-20-2004

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1208
Re: U/G condition Assessment To assess the best option more details are needed.
Diameter of pipe, wall thickness, the maximum bend that migh represent restriction of instrumentation put in the line, the presence of any fittings that migh restrict access and the length of line are a few that come to mind.

I have seen a small diameter pigging tool (I think it was an RTD instrument) and Oceaneering has a good selection of ROVs that could be useful too.

----------- Start Original Message -----------
: We have Oily water drain U/G lines that were found severly corroded and started leaking contaminating soil. These lines are C.S and externaly PE wraped. Please advise on available NDT methods that can be utilized to assess the condition of these lines without excavation.
------------ End Original Message ------------




 
09:35 Mar-20-2004

Gary

Consultant
TWI,
United Kingdom,
Joined May 2001
15
Re: U/G condition Assessment ----------- Start Original Message -----------
: We have Oily water drain U/G lines that were found severly corroded and started leaking contaminating soil. These lines are C.S and externaly PE wraped. Please advise on available NDT methods that can be utilized to assess the condition of these lines without excavation.
------------ End Original Message ------------

Teletest® is a novel non-invasive long range ultrasonic testing method for the rapid survey of pipes, for the detection of both internal and external corrosion. Other types of defect may also be detected.

The principal advantage is that long lengths of pipe, up to 175m (575ft) in each direction, may be examined from a single test point.

The benefits are:

Reduction in the costs of gaining access to the pipes for inspection.
Avoidance of removal and reinstatement of insulation or coatings (where present), except for the area on which the test head is mounted.
The ability to inspect inaccessible areas, such as at clamps or sleeved or buried pipes.
The whole pipe wall is tested, thereby achieving a 100% examination.





 
08:25 Mar-21-2004

John O'Brien

Consultant, -
Chevron ETC ,
USA,
Joined Jan 2000
278
Re: U/G condition Assessment This is one of those cases where you need a lot of details. In particular the issues over what degradation mechanism is occurring, reliability of NDE techniques to detect it and whether you need to size the damage. Access and cost become the next issues.

There are a number of techniques available.

Guided Wave UT is a screening option but effective ditance may be affected by access and the external PE coating.
Internal pigging tools will probbaly provide high quality data but you require access and they are not cheap.
There is a technique called No Pig from Germany which allows some screening with only contact at 1 km access points. Again it may not be cost effcetive.

Depending upon what you are looking at AE testing may also be able to produce effective data.

You need to consider a risk based screening approach with specific inspection selected at appropriate points.

Please contact me if you require more data.



 


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