Unusual Occurrence Causes Leak in High-Pressure Underground Gas Pipeline

"Unusual Occurrence Causes Leak in High-Pressure Underground Gas Pipeline"

Saatchi, A., Aghajani Koopaee, A.

MATERIALS PERFORMANCE, Dec. 2005

Abbstract :

A gas leak was detected on a 56-in cross-country gas pipeline, the Trans-Alaska Pipeline, on October 4, 2001, from a small orifice on the bottom of an indentation. A close-up of the hole revealed signs of impact from a foreign object and the splashing effect of white metal around it. The scanning electron microscopy (SEM) micrograph of the splashed region around the hole indicated a melted state and some porosity and microcracks were also visualized around the region. Three different zones were evident from the micrograph which included a banded bottom layer, a homogeneous grey middle layer, and a top white layer. The results support the theory that the high-energy impact of the steel bullet was involved.