Building on our efforts to enhance pipeline safety throughout northern and central California, PG&E has been an industry leader in supporting investments in new technology—including inspection robots.
In 2014, PG&E tested and implemented a variety of gas pipeline inspection robots. One such inspection robot is a customized "smart pig," which travels inside transmission pipelines and captures detailed information about the inside of the pipe without any interruption to gas service. These smart pigs travel inside pipelines to identify dents, cracks and corrosion before they become a problem.
Smart pigs rely on GPS mapping data, magnetic sensors and other technology to record detailed information from inside the pipeline. They can find defects as well as measure the thickness of pipeline walls. And, if corrosion or any other signs of weakness are found, repair crews are able to reach the part of the pipeline that needs work with precision.
PG&E also began testing a miniature robot that will allow the visual inspection of natural gas pipelines for signs of corrosion without the need for disruptive construction digs. PG&E joined with NYSEARCH—a voluntary research organization representing several gas companies in North America—and Honeybee Robotics to develop the robot prototype.
This robot is designed to travel through tight, rounded vents to the space between the pipe and casing to record the condition of each covered segment. The integrated cameras will allow PG&E gas crews to visually examine the health of the external surface of the pipe, the condition of the protective casing, detect any liquids and determine whether there is undesired contact between the pipe and casing.
PG&E has added another tool in its toolbox as it continues its progress to improve the safety and reliability of its gas system. Called the Pipetel Explorer, the untethered robotic device allows crews to inspect pipelines that are not accessible to other in-line inspection devices. The battery-powered robot can travel through a gas pipeline to identify defects in pipe walls. This device can successfully identify, size and pinpoint dents, metal loss and other potential issues. It is 12 feet long, weighs 250 pounds and has cameras on each end.
In recent years, PG&E has made significant progress in finding and fixing natural gas leaks on its 80,000-mile transmission and distribution gas system, including a 99 percent reduction in non-hazardous leaks in its backlog in 2013.
PG&E was the first utility in the country to test and deploy the industry's most sophisticated car-mounted leak detection system, which is 1,000 times more sensitive than traditional equipment. PG&E collaborated with the Silicon Valley-based Picarro scientists to refine the natural gas detection system.
The technology uses GPS to pinpoint even the most miniscule natural gas leak. Natural gas molecules are measured with a near-infrared laser. A high-precision wavelength monitor, meanwhile, ensures that only natural gas is being monitored, virtually eliminating the interference of other gases. Leaks are displayed on an iPad secured on the dashboard. If the system is in surveying mode, the information is automatically sent in real-time to Picarro's headquarters.
The technology also can tell in less than 10 minutes whether the gas being detected is natural gas or naturally occurring methane. Determining the exact type of gas using traditional leak-surveying would involve using a syringe to collect the gas and testing it a lab, a process that could take as long as a week.
PG&E's crews are now able to find 80 percent more leaks using this device, and the company is responding by accelerating repairs and increasing any necessary pipe replacement.
Currently, PG&E has six vehicles mounted with the Picarro Surveyor, with plans to add four more by the end of 2015.