TULSA, Okla. — Research funded by the National Energy Technology Laboratory (NETL) has resulted in the successful development of a unique new tool that can remotely repair plastic natural gas distribution pipelines without disrupting natural gas flow. The new tool also provides substantial cost savings, improved safety, and reduced environmental impacts.
That’s good news for the millions of American families and businesses that consume natural gas. The new tool is designed to repair the polyethylene (PE) pipe that comprises most of the nation’s 1.2 million miles of underground natural gas distribution pipeline system. Repairing PE pipe can be a costly, time-consuming, and dangerous job that entails substantial excavation upstream and downstream of the damage, halting gas flow, isolating and removing the damaged pipe section, and fusing a new pipe section into place. Such conventional repairs also cause lengthy disruptions to natural gas service.
Under a cost-shared project with NETL, Timberline Tools (Whitefish, Mont.) developed a remote repair tool that uses unique chemical and mechanical processes to apply a permanent external repair patch to damaged or defective PE natural gas pipe. The portable, lightweight tool has an open-jaw configuration that can fully encompass the pipe, so it can be operated by a single worker from the top down without the need to fasten the device under the pipe. Such an approach is undertaken remotely via a small “keyhole” excavation, which expedites repairs. More importantly, this approach keeps the operator out of an excavated trench and away from the risks of cave-in or other dangers. In addition, using a thermal-chemical patch to repair the pipe’s nicks and gouges or worn spots eliminates disruption to natural gas service.
The cost savings with the Timberline tool are significant: about 30–50 percent of the operation and maintenance costs. The tool has undergone extensive field testing by several natural gas utility companies across the United States, and the repair patches displayed no long-term unwanted effects on the pipe.
Timberline, which also developed a special squeeze-off tool for large-diameter PE gas pipe under an earlier NETL project, completed the repair-tool project in 2006. Based on the successes of this project, the company continues to optimize the repair tool to develop a single tool for 2-, 4-, 6-, and 8-inch PE pipe and to reduce the “time to market.” The natural gas industry has expressed strong interest in commercializing the tool, as it did with Timberline’s large-diameter-pipe squeeze-off tool.
NETL funded more than $600,000 of the roughly $875,000 project cost. Oregon State University also is participating in the research.
The Energy Department’s Energy Information Administration, in its latest annual energy outlook, forecasts that U.S. natural gas demand will grow by about 19 percent from 2005 to 2030. Investments in pipeline technology research will become even more critical to the maintenance and expansion of America’s natural gas transmission and distribution infrastructure required to keep up with that demand growth.