The utility recently used the 3D laser scanner to map the surface of a 16-inch standard PG&E gas pipe. The laser is bounced off round, reflective targets to read the tool's position relative to the pipe surface. It's being used by PG&E in the field and at its San Ramon testing facility.
The data it collects can be interpreted to see if corrosion on the pipe surface means that pipe is no longer safe to use. The old, manual method of testing for corrosion involves using chicken wire, spray painting a grid, and using a manual tool to measure corrosion depth. What could take up to two days, can be done in a matter of hours with the portable scanner which will be used for regular pipe maintenance inspections.
The 2010 San Bruno pipeline explosion happened because of faulty old welds that had never been properly inspected. The new scanner would likely not have found those internal problems, but it's still a powerful tool for improving PG&E's regular external pipe maintenance inspections.
"Using the laser scanner, compared to conventional means, would save, literally, hours and hours and hours," said PG&E Senior Welding Engineer Alexander Gutierrez.
"This is one of several technologies that PG&E has invested in and is testing right now," said PG&E spokesperson Brittany Chord.
The scanners can measure all the way down to 40 microns, about the width of the smallest human hair. They cost about $100,000, so cost could be a factor in whether or not PG&E will add anymore to its arsenal.