The San Bruno Gas Pipe Explosion

Welcome to CR4! and ga!

chris

Who told you that the ground was solid? Did you review the geological survey of the soil? Why do you think that there was one and only one explosion that occurred? Might the continuing flame from the burning gas line excavated some of the soil below the rupture. How many cubic yards of gas was initially ignited and how much continued to burn afterward. Now as far as ejecting the pipe out of the whole, do you really think that with this much energy being released in an uncontrolled fashion that metal pipes cannot bounce.

A forensic analysis is a difficult complicated act that should be done by qualified individuals that have access to all information. This is not CSI. The most critical information will not be found in the interesting pictures the press publish.

Are you missing something? Yes, you are missing almost everything.

I would expect that the initial blast was an overpressure burst that probably blew the soil and the gas into the air where it then became a fuel air bomb. Gas is compressible and will store a LOT of energy when compressed. That is why you don't pressure test with gas if you can possibly avoid it. Now as to what caused the burst I haven't a clue, it could have been a cathodic protection fault, a flaw in the coating that allowed a pit to form, a metallurgical flaw in a weld, Hydrogen embrittlement from various and sundry causes, or the pipeline could have been overpressurized due to a process control problem.

PG&E has directed attention towards corrosion issues in older pipeline infrastructure, which has now become the band wagon for the State politicians.

Latest is that it was overpressured to 375 psi due to a failed UPS procedure on the control station in Milpitas.

That much pressure would jiggle a lot of dirt, with air in it. How much of a gas/air bomb would you need for such a little hole, and how much hole was dug by that much gas pressure? Don't know.

The normal running pressure was almost that high. NO automatic shutoff valves, deferred maintenance. We have no idea if it had ever been nicked or deformed by heavy equipment loads. Time will tell. We really know nothing, and will know little when it's settled.

2.7 million miles of pipeline, but they only killed one person a month average in the last five years. Much safer than cars, I guess.

wiki

if you follow the coordinates link, and have google earth, it will take you there, and it is showing the real scene...

chris

As you zoom in, the aerial photos are taken prior to the blast showing a series of recent excavations in the road near the line. Impossible to tell whether these are related or not.

the sad thing here is any time a oil well or gas line oil line blows up you have no control over it. what you do have is a way to stop what happens after the blowout. time is where we fail the (shut down) time to long. also the back flow that is still in the lines has to end from both sides. the fireman said it took to long to shut down the line. it should have been done without waiting for the valves to be closed. i can prove the aftermath could have been shut down faster with no ones help. also the oil well fire in the gulf should have been done with out the lost of so much or the damage to the gulf. i have the only working emergency shutdown valve it has never failed.