Squeeze off tool

A joint effort between Timberline Tool and the US 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.

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 lightweight — only 60 pounds when fully assembled — 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.

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.

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 centres 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.