Putting the Squeeze on Natural Gas Pipelines

Tool Allows for Above-Ground Repairs of Large, Underground Distribution Lines

Washington, DC — A joint effort between Timberline Tool and the U.S. Department of Energy (DOE) has sped commercialization of the first “keyhole” squeeze-off tool for 4- to 6-inch polyethylene pipe. Through a Small Business Innovation Research grant, DOE funded the research and development of Timberline’s TopReach 650, an innovative tool that gets natural gas pipeline operators out of the trenches and lessens the monetary and environmental impacts of pipeline repair.

An operator lowers the Top Reach 650 over a 4-inch polyethylene pipe in preparation to squeeze off the flow of natural gas.

With more than a million miles of transmission and distribution pipes traversing the United States, the Energy Department is vested in supporting new technologies that contribute to safer, more efficient line maintenance. Support dollars are being spent on a myriad of technologies that increase safety, lower costs, and reduce impact to the environment.
 
The first step in repairing any polyethylene line is to squeeze off the flow of gas, similar to clamping a garden hose to stop the flow of water. Until now, squeeze-off tools for 4- to 6-inch lines have operated exclusively from below the pipe, requiring extensive excavations for access. Keyhole squeeze-off tools operate using a top-down approach and have been available for several years to clamp ½- to 2-inch piping. However, Timberline’s TopReach 650 is the first large-diameter top-down tool to be developed.
 
Conventional tools for large-diameter pipe weigh between 200 and 300 pounds, require two technicians and a backhoe for placement, and are transported by trailer among job sites. Safety is a prime concern because operators must work in the trench where the majority of repair-related injuries occur. In addition, the man-hours, equipment, and reclamation required to complete the job drive up the monetary and environmental costs of repairs.
 
Timberline’s new, out-of-the-box design is a victory for the industry. It is lightweight—only 60 pounds when fully assembled—it can be managed by a single operator, and it can be transported in the back of a pick-up truck. Excavations are kept to a minimum (the device can reach into a hole as small as 18” in diameter), and workers are kept out of the trench. Costs are slashed and job site safety is greatly enhanced.
 
Northwest Natural Gas Company worked with Timberline through the tool’s development, conducting laboratory and field tests and providing feedback on early prototypes. Now the company is a Timberline customer.
 
“There is absolutely a strong need for this in the field,” said Don Brost, a construction quality assurance supervisor at Northwest Natural. “This is the best we’ve found of its kind. We tried to break it for two years. We succeeded only once, and that was with the first prototype. They fixed it so we couldn’t do it again.”
 
Northwest is placing its first purchases with emergency units, because the tool is mobile and easy to use, and it gives the operator immediate shut down capability. However, the goal is to equip all 13 of Northwest's district offices and technical service centers with two tools each for both emergency and planned service calls.
                                       
Seven other companies are following suit and have committed to purchase over 200 tools, pending final approval by each company’s quality assurance division. This kind of response is a rarity in an industry where new approaches must often withstand years of field trial by one or two companies before being generally accepted.
 
Ken Green, president of Timberline, says this is because the TopReach 650 was developed in direct response to an industry need. “It all comes from the ground level,” he says.
 
The Office of Fossil Energy's National Energy Technology Laboratory oversaw the research and development of the TopReach 650, and project manager Rick Baker is pleased with the results. “Timberline’s keyhole squeeze-off tool is a Department of Energy-funded technology advancement that holds wide appeal to the natural gas pipeline industry,” Baker said. “I’m especially pleased we were able to reduce the amount of time to bring it to commercialization from a projected four years to just two. This tool will change the way the natural gas industry operates.”