Abstract
Each year, the U. S. Department of Transportation issues in July its "Annual Report on Pipeline Safety." That report incorporates information covered by the Natural Gas Pipeline Safety Act and the Hazardous Liquid Pipeline Safety Act. Included in that report are interesting summaries such as the two taken from the 1984 report. Table 1 and Table 2 list the number and cause of actual gas pipeline failures. Table 3 lists the liquid pipeline failures by cause and by product. Pipeline internal corrosion accounts for a noticeable percentage of pipeline leaks. In 1984, liquid pipeline internal corrosion accounted for about 5.5% of leaks reported. In 1985, the reported percentage increased to nearly 9%.
Although internal corrosion can be mitigated by use of corrosion inhibitors, thin film cured coatings, or by use of expensive alloy pipe, internal corrosion of pipelines can now be halted by use of a field installed, 100% holiday free, polyethylene liner suitable for use in low, medium, and high pressures at temperatures below 150°F to 180°F. It works because it separates the flowstream from the metal pipe, is tested to be and remain 100% holiday free, and is resistant to all but a handful of the nearly 3,300 known man-made chemicals within its temperature use range. This particular polyethylene liner is a very tough, inert material which does not rust rot, pit or corrode.
Long term performance of the liner in hostile environments include brackish salt water, wet CO2 gas gathering, wet sour (H2S) natural gas, mild slurries, solution mining (SX), multiphase crude oil pipelines, offshore piplines and nitrate fertilizer pipelines. Here, during the past nine years, about 600 miles of liner has been installed in a broadening range of applications and sizes. Properly designed, installed and operated, the lined pipeline functions without corrosion or problems providing high performance against aggressive media.
