thePetroStreet

Anyone has used LRUT for inspecting the higher diameter flare line(18"-42")?Is it effective to detect the internal corrosion with moderate amount of scales in the piping system?Any limitations?Use experience sharing is highly appreciated.

regards,

Go through these threads:
http://www.thepetrostreet.com/forums/vi ... 276&p=1081
http://www.thepetrostreet.com/forums/vi ... =234&p=983
These may help you.

Is the whole line aboveground?

Why do you want to opt for LRUT in case of flare piping?
Is the piping insulated?
What's the line temperature?

Due to severe internal corrosion we want to carry out 100% scanning on the entire header(5 km length).The manual scanning will take long time that is reason we want to try LRUT.LIne is located in the above ground.Thickness range is 10-14 mm.

There would not be any limitations of LRUT technique in your case.
I think you are aware of this fact that LRUT would only be screening. You have to use some assisting UT technique along with LRUT at certain locations of lower thickness so as to have actual readings of minimum metal thickness.

For one of over pipeline in diameter ranges from 10" - 18" we successfully carried out LRUT inspection.
At almost every 100-120 meters, holding points have to be set for equipment mounting.
After performing LRUT, we scanned the lower thickness regions of pipeline with manual UT (straight probe).

If the length is long like 05 meters, yes LRUT is the best option as it would probably be saving inspection cost also in addition to time.
Though like others have mentioned, after screening, for actual thickness measurements you have to undertake manual UT also. Straight probe on base metal and shear wave technique for weld joints if found corroded.