Erosive Failure of Natural Gas Pipes

Abstract

This paper presents the study of the sequential failures of a nominal pipe size 8 (API 5L X42) carbon steel and SDR 17 medium density polyethylene (MDPE) pipes near a high-pressure water pipe. The study was conducted by reviewing the background information and visual inspection on failed specimens. The investigation revealed that a jet issuing from a water pipe joined with surrounding soil to form a slurry with highly erosive properties. The impact of this slurry upon the pipe caused the loss of pipe coating material and thinning of the pipe surface, which eventually led to its failure. Subsequently weaker ground support caused the MDPE pipe to sink into the high-speed gas jet from the failed API 5L X42 pipe. The high impact of the gas jet physically hit the MDPE pipe, causing its rapid erosion.