After finding one service tee improperly installed on a new PE gas main, a gas utility in the northeastern US had to inspect every service tee in the area to confirm all services tees was installed properly. Rather than digging hundreds of excavations in a quiet, residential neighborhood, this gas utility looked to trenchless technology and new methods to significantly reduce costly and disruptive excavation by 87%.
Client : Undisclosed Gas Distribution Utility
Location : Northeast US
Project Duration : 17 days
Project Completed : October 2014
Example of an improper tee installation. The cutter has not fully penetrated into the gas main.
Example of a successful tee installation. The cutter protrudes slightly into the gas main.
In order to pass inspection, the mechanical cutter of the PE bolt style service tee must fully cut through the wall of the gas main. This works to secure the tee in place and ensure the flow of gas to the customer is not blocked. Using the patented PRX250 Live Gas Main Inspection Camera System, ULC Robotics’ crews inspected multiple tee installations from a single excavation.
ULC Robotics worked closely with the gas utility to plan strategic entry points that maximized camera travel distances and validate tee installations in real time.
Using ULC Robotics’ In-Pipe Locating service, our crews were able to inspect 286 tees through 38 excavations. The use of live gas main cctv cameras reduced excavation by 87%. Data obtained through camera inspection of the plastic gas distribution mains showed that 35% of the installed tees did not pass inspection. With the ability to locate the camera from above ground, ULC Robotics was able to tell the gas utility exactly where to dig. Because the gas main camera inspection is performed live, there was no disruption of service to customers.