Internal Pipe Repair System

70797 Pipe and/or joint leakage is a critical problem for both the transmission and distribution of natural gas. Most distribution and some transmission systems are located in densely populated urban settings, and these pipeline defects would jeopardize the safety of the surrounding public if left unrepaired. Although external repairs are practical, many collateral costs (associated with traffic control and disruption, public and worker safety, waste disposal, and pavement restoration) result in an annual cost of over $150 million to the gas industry. This project will develop an internal pipe repair system that seals leaks in pipes and joints from the inside of the pipe. The concept consists of a self-expanding, narrow band of composite material that is circumferentially aligned with the pipe defect and confines a bead of sealant between itself and the pipe wall. Phase I will (1) demonstrate the feasibility of a self-expanding sealing band combined with an expanding foam sealant to stop leakage through the pipe wall and/or joint; and (2) develop the engineering parameters needed for the selection of an acceptable material for the sealant compound and sealing band, based on pipeline diameter, wall condition, pipe material, and type of defect. Commercial Applications and Other Benefits as described by the awardee: Gas leakage results in unsafe operating conditions for working crews, the general public, and the end consumer. In addition, unaccounted-for gas (including gas leaks) results in millions of dollars in lost revenue for the gas utilities annually. The internal repair system should greatly reduce the cost for repairing gas main leaks in both transmission and distribution pipelines located in urban settings. Use on water and sewer lines also would be expected