Robot Inspects Live New York Natural Gas Pipeline
In a field demonstration filled with “firsts,” a self-powered robot developed by the Northeast Gas Association, Carnegie Mellon University, and the Department of Energy’s National Energy Technology Laboratory successfully inspected a mile of a live natural gas distribution main in Brockport,New York.
Known as EXPLORER, the remote-controlled robot was launched and retrieved four times on October 8 with no interruption in customer service. The system successfully made its way through an 8-inch diameter pipeline owned and operated by Rochester Electric & Gas, and maneuvered several 70- to 90-degree bends.
This is big news for the U.S. natural gas industry, which must maintain more than a million miles of pipelines. The demonstration marked the first introduction of this type of internal inspection system into a high-pressure (60 pounds per square inch) pipeline. The mile it traveled set a record for an untethered pipeline inspection system.
The EXPLORER robot is equipped with a miniaturized fish-eye imager that sends pictures of the pipeline to a monitor above ground through a wireless connection. Because it provides pictures of a pipe’s interior in real time, the system provides an accurate, complete view of a pipeline’s health.
In June, EXPLORER was placed inside a low-pressure, 8-inch gas main owned and operated by Con Edison in Mount Vernon, New York. The robot successfully inspected 2,150 feet of pipe that was originally installed in 1890. Cameras mounted on each end continually transmitted visual images to an external monitor over the wireless connection.
EXPLORER’s main advantage over traditional pipeline-detection systems is its innovative modular design, which resembles a series of sausage links strung together. Each of the system’s seven modules houses components that enable it to function properly. Articulated joints connect each module to the next, giving the 6-foot robot the flexibility it needs to twist and turn and make sharp, 90-degree bends as it travels through pipelines 6 to 8 inches in diameter.
More conventional, larger inspection systems cannot pass through such narrow, winding configurations. Without a robot like EXPLORER, the only way to inspect such pipelines would be to dig and view them from the outside, a major expense in urban areas.
The first and last modules have cameras with a 190-degree field of view which transmit high-resolution color images of a pipe’s interior as EXPLORER searches for leaks. Because the first and last module have their own cameras, the system provides views at either end, allowing observation during travel in both directions. An operator can view the two images separately or simultaneously.
The information an operator receives determines how a pipe will be repaired if a leak is detected. For example, an operator has to decide whether a faulty pipe should be spot- or section-repaired, relined, or replaced based on in situ data.
The ease with which EXPLORER can be placed inside a pipe is another bonus. Only one hole needs to be drilled, and, in densely populated areas, creating numerous holes is often the most expensive part of pipeline inspection. Once inside, the system can accurately check a neighborhood’s entire natural gas pipeline network in a matter of hours.
This successful demonstration has paved the way for the second phase of research: EXPLORER II. This prototype will be a more rugged platform equipped with advanced sensors being developed through the Energy Department’s Natural Gas Delivery Reliability Program.
The National Energy Technology Laboratory is the lead field center for the Office of Fossil Energy’s research and development program.