The October 2019 revisions to US federal rules governing natural gas pipelines require Operators to establish vintage and manufacturing process for line-pipe assets with incomplete records. Vintage and manufacturing process are considerations when establishing populations of pipe for maximum allowable operating pressure (MAOP) reconfirmation, materials verification, and integrity management programs. Additionally, the rule changes establish an allowance to utilize in-situ nondestructive examination (NDE) technologies to verify line-pipe material properties including strength, composition, microstructure, and hardness.
Economic and market demands have driven changes in steelmaking technologies and pipe-forming approaches. Knowledge of the relationships between processing, microstructure and mechanical properties have been fundamental to the evolution of steel line pipe manufacturing. Product specifications and standards for the manufacture and testing of pipe and tube have crystallized this evolution as performance expectations increased. The resulting manufacturing process changes have left a variety of “fingerprints” observable from in-situ materials verification NDE data, when analyzed holistically.
The purpose of this work is to enable operators to begin leveraging these fingerprints to illuminate the vintage and manufacturing process of their line pipe assets using the NDE data. A method is proposed to re-establish line-pipe asset manufacturing and vintage records using historical line pipe manufacturing practices and NDE materials verification data.