Assessing the integrity and increasing the service life of HPFF pipe type cables

Electric utilities in the United States are currently utilizing over 4000 miles of high pressure fluid filled (HPFF) underground transmission lines. Most have been in service in excess of their 30 year design life with some being in service as long as 60 years. The systems have proven to be robust with very few problems and have required little or no maintenance. Over the years the pipe type cables have increased in their importance as part of the backbone of the transmission systems. As the systems continue to age new strategies need to be utilized to insure their ability to provide safe and reliable service. The following is a well established integrity program designed to assist asset managers properly maintain aging pipe type cables.