Replacement of 8-Inch Gas Transmission Pipeline With Smartpipe® Composite Liner in Roanoke County, Virginia

Abstract This paper provides an overview of Enbridge Gas Transmission and Midstream’s PHMSA special permitted project to install and use Smartpipe® to retrofit 0.64 miles of an 8-inch diameter, 1965 vintage steel pipeline, known as the Line 3320A-100. The new 6.25-inch internal diameter (ID), 7.6-inch outer diameter (OD) Smartpipe® was inserted through a small segment of the existing 8-inch diameter steel pipeline, which improves pipeline integrity and safety by eliminating corrosion and increasing resistance to third-party damage. Smartpipe® also significantly reduced the environmental impact and disturbance associated with the excavation, earth disturbance, and other activities that would have been necessary with removal of the existing 8-inch diameter steel pipeline and the installation of a new steel pipeline in the right of way (ROW). In addition to an overview of the engineering design and construction of the project, the short- and long-term use case of the Smartpipe technology over traditional materials is explored. Smartpipe® offers a high strength composite pipe liner solution that involves a trenchless installation within the existing steel line to minimize disruption to both operations and the environment. Embedded fibre optics within the Smartpipe® offer real time leak detection monitoring capabilities and ROW activity real time monitoring along the entire length of the pipe. This ESG centric solution not only provides a reduction in carbon footprint when compared to traditional construction methods (open trench pipe replacement and horizontal directional drill replacement) and it is designed to address high consequence and difficult to access areas where operator systems may pass through. Smartpipe® has high pressure capabilities to provide repurposing opportunities for aging, derated and abandoned pipe assets. Smartpipe® is DOE tested for hydrogen use and compatibility with CO2 to provide a bridge to future energy sources. This study serves as a valuable case for industry professionals, offering lessons learned, a PHMSA special permit application template for Smartpipe® replacements as well as education and knowledge on the Smartpipe® technology and installation considerations.