Pipeline Sectional Replacement "Weld" Defects

[Matthew78]

Please I need an urgent help on this.

I have a section of an old pipeline with crack detected earlier this year on it. The management decided to shutdown and do a repair by cutting out a 12m length and replacing with a new section of linepipe. The line in question is 24 inch, API 5L X52. Unfortunately, after the sectional replacement, NDT results show unacceptable weld defects sizes (LF, IP and inclusion) in both welds carried out. The reason given for this was that too much magnetization was experienced during the welding process.

As is, repair is inevitable. We were advised to repair with full encirclement sleeve but a senior personnel kicked against it saying the defect locations may serve as a location for carck initiation. I am presently in a fix for the solution to fix this sort of problem. I searched API 1104 and 2201 and could not see any mention for repair of supposed "Golden Weld".

Is there any with any experience in such who can help with an idea of how to solve this problem? Please kindly help on this.

 

[Jason8zhu]

ECA I think the engineering critical assessment (ECA)can first be carrried out to check if the defect is acceptable for the design load during operation.

 

[DekDee]

A weld repair in a "Golden Weld" is treated exactly the same as a "Normal Weld".
Repair it or cut it out - up to you,
Cheers,
DD

 

[BigInch]

I have to agree that many very big problems start with small inclusions and weld defects.

Most companies call for complete cut out and replacement, not encirclement. Encirclements might be used to repair a critical operating pipeline that is very difficult to shut down, however you seem to be working with a line that is stopped, so take advantage of that and do a full cut out. Why start the race behind the last car when you can choose to have the pole position.

 

[LittleInch]

Matthew78,

There's something not right here.

you have a fault on you pipeline, you shut it down, drain or blow the contents out so that you can perform a cut out an repair.

You weld it back in. seemingly you are not hydro testing this new piece so it needs some NDT on the weld. This shows up some faults in the weld. Now comes the odd bit - why did you let the pipeline go back into service with faults or prior to the NDT results being seen / reviewed. This is not what you would expect to happen, especially where you have "golden welds". please explain a bit more what happened.

what sort of full encirclement sleeve? Welded? grouted?

Too much magnetisation - De-gauss the pipeline - this is quite common to get for older lines, but also quite fixable.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.