The gas industry spends over $150 million per year repairing gas mains. Gas leakage results inrnunsafe operating conditions for the working crew and the general public. An internal repairrntechnique that could minimize and/or eliminate some of the problems and costs associated withrnexternal repairs of pipelines would be of significant benefit to the gas industry. A repairrntechnology is needed that can be inserted into the pipe through a small keyhole excavation. Therntechnology should also be adaptable to several possible delivery platforms including autonomousrnrobots, snakes and crawlers.rnThe internal pipe repair system is designed to address the many technical issues associated withrnpipeline problems including sealing leaks in pipe joints from the inside of the pipe and/orrnreinforcing the pipe wall from either mechanical dents or corrosion induced pitting. The conceptrnconsists of a self-expanding, narrow band of composite material that contains (and ultimatelyrnconfines) a bead of sealant. The band is circumferentially aligned with the pipeline defect, andrnsealant is dispensed onto the band as it is released from the carrier. The band is fed from therninside of the carrier as the carrier rotates around the inside of the pipe. Once released from itsrncarrier, the band self-expands outward and grows to the inside diameter of the pipe.rnBased on the analysis and testing performed, the ability to internally deliver and deploy a selfexpandingrncomposite band to seal a pipeline leak is achievable. This approach requires a short,rnlow-cost composite material and a suitable adhesive. Preliminary studies indicate that thernmaterial cost for this type of repair would be less than $25 per leak. Adapting the system tornstructural repair will present a challenge that will require additional research.
展开▼
