Pipeline lamination 2

[sam62]

Hi all,

what are the possible factors that can have an effect on a burried pipeline lamination, in terms of growth for ex.?

Thank you

 

[Goahead]

According to ASM Glossary:
lamination is a type of discontinuity with separation or weakness generally aligned parallel to the worked surface of a metal. May be the result of pipe, blisters, seams, inclusions, or segregation elongated and made directional by working.

Laminations should not be present in buried pipes of operating fluid transfer systems. The same factors that would cause growth of fatigue cracks might cause also expansion of laminations.

http://www.welding-advisers.com/

 

[SJones]

The factors that would affect the growth of laminations are: The stresses imposed, the current size of the lamination, and the resistance of the surrounding material to the growth (probably related to fracture toughness). BS 7910 or API RP 579 can then help you further.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[unclesyd]

What is the physical dimensions and operating parameters of the pipeline and process fluid being transported.

I have seen laminations due to manufacturing problems that lasted for years and other that after a change in service started to enlarge due H2/CH4 generation or corrosion.

I have seen so called laminations that were actually H2/CH4 blisters caused by the process lay dormant when the process fluid was changed and in several years start to increase in volume.

You need to ascertain the origin of the discontinuities in the pipe.

 

[sam62]

To unclesyd:

NPS 10, w.t: 5.16 mm, Operating Pressure:10 000 kPa.
Product: Crude oil.

 

[unclesyd]

sam62,

Am I reading your correctly .2" wall holding 1450 psi?

 

[sam62]

unclesyd,

apologies for the mistake and the delay.

Please read MAOP instead of Operating Pressure.