The results presented briefly in this paper and in detail in Refs demonstrate the capabilities of ATC's patented portable/in-situ stress-strain microprobe system and its automated ball indentation (ABI) test technique to non-destructively and reliably measure the yield strength, the stress-strain curve, and the fracture toughness of samples of carbon steel materials from various natural gas pipeline manufacturers. The accuracy, reliability, and easy field applicability of the SSM technology in testing pipeline materials with unknown properties have been demonstrated in this work. Reference was reviewed favourably by the US Office of Pipeline Safety (OPS) in December, 1999, and the SSM technology is recommended for use by the pipeline industry. The test results from the work in Reference provide the technical basis for: (1) a pipeline operator to submit a waiver to the OPS of the US Department of Transportation (DOT) to use the ABI test as an alternative to the tensile test, and (2) preparing an Amendment to 49 CFR 192 Appendix B to allow nondestructive ABI testing as an alternative to the destructive and expensive tensile testing to measure the yield strength and the stress-strain curve of steel pipeline with unknown properties. The use of the SSM system to test pipelines in the field will improve their structural integrity evaluation as well as their operational efficiency by allowing safe up-rating.
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