In July 2009 — more than a year before the San Bruno explosion — we warned about the dangers to the public posed by PG&E’s aging underground infrastructure.  Back then, we were focusing on the utility vaults hidden beneath the streets and sidewalks of San Francisco and other urban areas.  They have a long history…

Where will the San Bruno fire cases be heard? This morning, Judge Forcum ruled that all of the cases should be heard by one judge, and that judge should be in San Mateo County. That was no surprise. Now, it’s up to the Chief Justice of the California Supreme Court to approve Judge Forcum’s ruling.

As reported by the San Jose Mercury News, the "mystery" as to why the pipe ruptured appears to be solved. The NTSB found that the pipe was not properly welded, even by 1956 standards.  The welds were supposed to go through the whole pipe but didn’t.

In the area of pipe identified as the spot where

…

Though more than 30 homes were destroyed by the PG&E gas explosion, many more suffered damage that is not visible from the street.  Getting cracked chimneys, leaky roofs, and broken windows repaired has been, for many homeowners, an overwhelming battle of paperwork, engineering reports, claims forms, and phone calls.  Some homeowners have given up trying.  As…

PG&E documents said that Line 132 was of seamless construction.  As it turns out, it was not.  It was of weaker, welded construction.  As I wrote here, welded seam pipes have long been known to be dangerous.  To run them safely, the utility company should pressure-test them with water to make sure that…

PG&E didn’t document the fact that Line 132 had welded seams.  So really, what’s the big deal? Aside from proving that PG&E is sloppy on its paperwork, what difference does make?

Plenty.

Back in 1998, the Department of Transportation sent out to all utilities, including PG&E, a Safety Alert (see below).  The Alert explained that pipes with welded seams (known as “ERW” pipes) are dangerous.  Special precautions need to be taken to make sure they don’t explode. For example, the pipes should be periodically tested to make sure they are sound.

Because PG&E’s paperwork said that the pipe was not ERW pipe, PG&E took none of the recommended safety precautions.

One of the problems with ERW pipe is that the welds are subject to a type of corrosion that is hard to detect.   According to the Alert:

ERW seams have been involved in 145 service failures . . .since 1970, and . . .all but 2 occurred on pipe manufactured prior to 1970. . .selective seam corrosion appears to  be a contributing cause of failure in a significant number of these incidents. . .

If the welded seam pipe was installed before 1970 (as was Line 132) the Alert called upon the utility to not just review the pipe’s history, but to fill it with water and pressure test it to make sure it is sound.

All operators who have pre-1970 ERW pipe in their systems should carefully review their leak, failure, and test history as well as their corrosion control records. . .operators should consider hydrostatically testing to ensure the integrity of the pipeline.

It appears that PG&E neither conducted nor even considered hydrostatically testing Line 132, despite the fact that Line 132 was suspect pre-1970 ERW pipe.

Did PG&E fail to properly document the type of pipe running through San Bruno due to a mere oversight?  Or did PG&E deliberately fail to document the pipe so that it wouldn’t have to conduct the expensive and time consuming hydrostatic tests?

Safety Alert re Welded Pipe

Continue Reading San Bruno Fire: PG&E Was Supposed To Test Welded Seam Pipe

More than 30 lawsuits have been filed in San Mateo County. Judge Steven Dylina was assigned to preside over the cases. Pursuant to his order, all the lawyers working on the cases met on December 2 to discuss amongst themselves how the cases should be handled. After that meeting, Judge Dylina set a first court date of December…