Thursday, September 15, 2016

Salem: Spectra found 30% wall loss in 2012 and took no action.

This is incredible.

New info in the Salem, Westmoreland Co., PA failure of the TETCO (Spectra).
in 2012. An inline inspection found 30% wall loss!!
And Spectra took no action.

Four years later it failed, scarred a man for life, destroyed his home,

Andy Drake, vice president of operations for the Houston-based company, says the corrosion was revealed during a 2012 inline-pipeline inspection. It showed a 30 percent decrease in the thickness of the pipeline's wall.

"It was very small. It was smaller than any threshold we would have been required to [take] action on or investigate," Drake says. "The anomaly grew at a significantly higher rate than anything we've seen in the past."

Spectra says, essentially, it failed sooner then we expected.

30% wall loss seems like significant corrosion to me.
Why did Spectra do nothing?

The Spectra rep quoted in this article indicates they have prioritized all of their anomalies, and concluded a spot of 30% loss in a Class-1 area, doesn't make the cut in 4 years.

This makes perfect sense from a cost-benefit equation,
but is astounding from a pipeline safety perspective.

Line 27 was installed in 1981.
So even if we assume linear rate of corrosion,
then we have about 1% wall loss per year.
30% in 30 years.

The Spectra guy is saying is they took no action
(essentially) because 1% corrosion per
year is nominal, 30% loss is not an action threshold
(at least not in Class-1), and they have worse problems
in the field.

Sweet baby Jesus.

So he is implying, something site-specific happened since 2012
which increased the rate of corrosion FASTER than 1% per year,
which is what they expected.

My head is swimming contemplating this question:

If 1% per year is considered nominal wall loss
even with best technology in 1981 inc. CP,
and a spot of 30% loss is non-actionable... wow.

What does this imply about the shape of our national pipeline system?

IMO-- PIPELINE OPERATORS should prioritize the following sites
for evacuation and inspection: Corrosion anomalies near:
  • 1) wet areas (e.g., creekbeds)
  • 2) within 5 miles downstream of a compressor
  • 3) nearby sources of stray DC, such as CP systems from foreign pipelines (at crossings and/or co-located ROWs), bridges, railroads, storage tanks, or other sites where CP is used.



May you, and all beings
be happy and free from suffering :)
-- ancient Buddhist Prayer (Metta)

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