It is estimated that there are about one million kilometers of gas and liquid transmission pipelines operating across the globe today. Pipelines, owing to their strategic role of transporting gas and liquid fuels, are of immense capital value. Potential degradation and failure of pipelines is a sensitive issue both with the public and legislative bodies, since the consequences of failure could include injuries and death. In addition, pipeline failures have severe financial consequences. More than half the pipelines in use today are 30 or more years old and invariably have experienced some deterioration. Preventive maintenance using nondestructive evaluation (NDE) techniques plays an important role in ensuring safe pipeline operation [1].