Fracture control plan

[09091960]

If one have to carryout fracture controll plan for 40 years old gas pipe line what methods use to address the issues related to interaction with weld heat effected zones, considerations for corroded pipe etc. For a newly fabricated pipes sample testing is a possibility where as old corroded pipes should have some procedures to incorperate these issues to the plan.Appreciate your feed back on this subject.

 

[grampi1]

Normally one is not required to meet the latest code requirements on a line built to an older code.

A line 40 years old may have a large range of toughness properties. First stop is to look at the original material certificates as perhaps some toughness data will be present on them.

Gas pipelines on land do not require a fracture control plan for girth welds. Fracture control plans normally refer to pipe base metal toughness properties. If however, you now find a concern over displacement like seismic, girth welds could be a problem.

 

[metengr]

What methods? I would review ASME/API 579 FFS-1.

 

[brimmer]

As noted above, API 579 suggests a variety of eng. assessment for pipeline and various components. Also, PDAM is a good manual. A suggestion, check and see if your pipe was constructed with low frequency ERW longseam (many up to approx 1970 were), as there have been many issues with this type of longseam. You will need to select and write which assessment criteria you will need to use for which type of defect.