Evaluation of Stress Corrosion Cracks in Pipelines 1

[Heyns1]

ASME 31G for the evaluation of “the remaining strength of corroded pipelines” but it is not used for crack like defects.
What code can I use as a reference for the evaluation of Stress corrosion cracks in pipelines under pressure?

Thank you

 

[BigInch]

Best thing is to talk to your metallurgist.

ASME G103 might help

http://www.astm.org/Standards/G103.htm

with some additionl hints here,

http://www.npl.co.uk/upload/pdf/stress.pdf

From "BigInch's Extremely simple theory of everything."

 

[stanweld]

The first step is to accurately define the cracks' size (length and depth). Determination of the the current growth rate is another problem.

 

[brimmer]

For predicting burst pressures you could use CorLas, modified NG-18, PAFFC, even KAPA (has option for crack like) or API 579 & BS 7910. CorLas seemingly shows the best correlation in burst pressure tests. You would need to know the toughnes values of the pipe for increased accuracy. Then as per stanweld you would need to get a proper length and depth of the crack, for SCC I would recommend to use maximum interlinked length.

 

[stanier]

First you need to establish why SCC is occurring in the first place. Is the environment the same now?

SCC crack growth is a bit like buckling, lightning or earthquakes. it is not something you can put a number on when it comes and bites you.

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