If operators do not have adequate records to establish the material properties of their pipeline assets, material verification that produces traceable, verifiable, complete (TVC) records is required. With this requirement, operators are seeking engineered methods that produce TVC records and accurate, reliable information to ensure their pipelines are operating under their maximum allowable operating pressure (MAOP). HSD Testing in-ditch can be used in addition to enhanced inline inspection to characterize material properties and reduce the number of costly repairs.
Combined Strategy for Effective Material Property Verification
Enhanced ILI. Enhanced ILI provides an overview of the pipeline, recreating the condition and describing the various populations of pipe. Operators can better understand the baseline condition of the pipeline using enhanced ILI techniques.
NDT Inspection. State-of-the-art NDT inspections, such as those performed using the MMT HSD Tester, verify the ILI data and augments the baseline established by ILI with accurate and reliable material verification data. The required material verification, including grade, wall thickness, diameter, and pipe type, can be determined using the in-ditch measurements from the HSD Tester. These material properties are also important for assessing integrity threats such as corrosion or crack-like features.
Integrated Seam Weld Identification
Identification of seam type is an important aspect of meeting new regulations. ILI can provide an initial assessment that can be supported by the information gathered by the HSD Tester. The HSD tester can measure variations in hardness across the width of the ERW seam to identify properties from different welding processes and post-weld-heat-treatments (PWHT).
MMT’s HSD testing methodology can also identify high frequency, low frequency, or high frequency normalized heat welds that have undergone PWHT.
The HSD Tester verifies the strength properties data acquired through ILI. MMT’s methods have been validated through the Pipeline Research Council International (PRCI) program NDE-4-8, which concluded that MMT’s HSD was the “best performing” technique. Combined with engineering analysis, the HSD can also account for measurement uncertainty or potential inaccuracies.
By using HSD’s strength measurements, operators can take advantage of MMT’s extensive, robust data analysis process and machine learning applications to verify the ILI data.
Pipe Grade Determination
ILI measurements can be used to make a best-fit grade determination, and when supplementing material verification from in-situ HSD testing, operators receive refined results with added confidence. The material verification requirements established by 192.607 regulations require strength properties determined with NDE methods must account for uncertainty. Both ILI and the HSD Tester meet this requirement. Both have defined tolerances and confidence limits for the yield strength (YS) and ultimate tensile strength (UTS) of individual pipes.
The HSD Tester provides key NDE material verification information that can be integrated into operators’ comprehensive, holistic integrity management plan. To learn more about the possibilities for integrating ILI and NDE testing for pipeline integrity, including case studies, read MMT and Rosen’s joint paper from PPIM 2020 here: bymmt.com/publications