Integrating Automated Ball Indentation with ASME B31G Code to Assess Remaining Integrity of Corroded Pipelines

This paper demonstrates a complete fitness-for-purpose workflow combining in-situ ABI® yield-strength measurements with ASME B31G corrosion assessment calculations. It provides pipeline operators a practical method to avoid overly conservative assumptions by measuring actual pipe grade rather than relying on potentially inaccurate records.

The ASME B31G code is the standard method for evaluating the remaining strength of corroded pipelines. It requires knowledge of the pipe's specified minimum yield strength (SMYS) — but for many older pipelines, accurate records of pipe grade are unavailable. In the absence of verified data, operators must assume the lowest possible grade, leading to conservative assessments that may trigger unnecessary pipe replacements costing millions of dollars.

By combining in-situ ABI® measurements with B31G calculations, this paper demonstrates that operators can determine the actual yield strength of the pipe in the field, use that measured value in the B31G assessment, and make fitness-for-purpose decisions based on real data rather than worst-case assumptions. The economic impact is significant: accurate yield strength data can change a B31G assessment from "replace" to "continue service," potentially saving millions per assessment.

This application is directly relevant to the undocumented legacy pipelines now subject to PHMSA's 49 CFR §192.607 (2021), which requires operators to verify material properties of pipelines with unknown or incomplete records through nondestructive or destructive testing.