Lightning damage pictures

Following the earlier post on lightning damage I have acquired a few photos.  The donors wish to remain anonymous but I am very grateful to them.

The first three pictures are of the recently reported event which resulted in a leak.  The the small stick inside the defect was to prevent any trace of gas from diffusing out after the pipeline section was blown down to atmospheric pressure.  Apart from anything else it is interesting that a hole in the pipe as small as 1.6 mm could create such a large hole in the ground.  It is easy to forget what high pressure gas can do.

Hole in ground above the leak

Defect as found

Defect after grit blasting

The final photo is of a deep but non-penetrating defect that was found through in-line inspection.  The effect on the coating is very different to the defect above – it looks as if the hole in the coating here is no larger than the crater in the steel and coating is only slightly blackened, whereas in the photo above the coating has been burned off or charred for a considerable distance.

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5 Responses to Lightning damage pictures

  1. Chris Hughes says:

    Was the coating just ordinary yellowjacket in both cases? Bredero used to offer a version of Yellowjacket where the HDPE was actually bonded to the steel rather than floating over the mastic: that might explain the difference between the two effects. Not sure whether they sold much of it.

  2. petertuft says:

    The pipeline in the first photos had conventional HDPE-over-mastic Yellowjacket but I have no information on the second case.

  3. matt says:

    Fascinating. I can see why you don’t get a lot of clues about the lightning path through the soil! Many thanks to your source.

  4. petertuft says:

    Received by email from a reader who had trouble posting directly here:

    “Viewing the photo it appears that the defect is a result of lightning flash discharging to earth. Since most coatings are designed to resist high voltages, I assume the exit point is not random but the site of a coating defect. Ideally the lightning flash would be directed to earth via a dedicated earthing electrode. Possibly the pipeline is in near contact with a metal structure that discharged the flash to the pipeline.”

    At face value it sounds plausible that the site might be a coating defect. However I know there is concern about burning holes through coatings by “geeping” at too high a voltage prior to lower-in of a new pipeline, and lightning would be at a much higher voltage than anything a geeper could generate. Maybe there is indeed a defect at the site, but it might need to be only a micron-sized pinhole.

    Also, I think most pipelines are well-connected to earth via surge diverters at stations. Doesn’t seem to solve this problem though.

  5. Recent research reveals lightning strikes to occur repeatedly at or near fault lines and mineral deposits. Where these areas and pipelines intersect, the likelihood of damage is higher and more frequent. Another issue to contemplate besides lightning bolts would be solar eruptions. When large CME’s impact earth (although not as often) they energize the whole ground….the pipeline as a whole could be energized and the energy can be transferred into the ground at said faults and deposits causing damage.

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