Last month, the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration (PHMSA) alerted the public to its April 1, 2022, response denying a petition for reconsideration of the final rule titled “Safety of Gas Gathering Pipelines: Extension of Reporting Requirements, Regulation of Large, High-Pressure Lines, and Other Related Amendments.” This amended the Pipeline Safety Regulations at 49 CFR parts 191 and 192 to introduce reporting requirements for previously unregulated Types C and R gas gathering pipelines along with safety standards for Type C gas gathering pipelines.
Under the PHMSA MEGA Rule pipeline companies are to adhere to the following requirements and timeline:
- Integrity Management Plan in place and all required procedures documented by July 1, 2021
- 50% of pipeline mileage verified by July 3, 2028
- 100% of pipeline mileage by July 2, 2035
Additionally, this ruling requires that records confirming MAOP (Maximum Allowable Operating Pressure) and material properties be traceable, verifiable and complete, leaving operators to interpret what that means for them.
It’s important to note that one of the first pieces of data that should be gathered is the elemental breakdown of the pipe material.
Fatal accidents and injuries, as well as leaks, premature pipe replacements, loss of property, and unplanned outages at refineries, chemical plants and gas processing facilities often can be traced back to equipment failures due to faulty or counterfeit metal building components or because piping is made from material that does not meet specifications. Changing the amount of carbon in these products can change the properties of the steel including tensile strength, hardness, weldability, ductility, and corrosion resistance. It could event affect the safety of your operations, so identifying the material is crucial.
Perhaps the most significant change, however, is the now limited applicability of § 192.619 Maximum allowable operating pressure: Steel or plastic pipelines, commonly referred to as the “grandfather clause,” for confirming MAOP, the maximum pressure a pipeline can safely operate. This clause allowed operators to confirm MAOP using the highest pressure recorded within a five‑year period that predated July 1, 1970. No test records were required nor knowledge of what exactly was in the ground. That’s a lot of unknown information on numerous pipelines in the U.S., many of which are still around and in service today.
In addition, pipelines constructed of cast and wrought iron, as well as bare steel, are among the oldest energy pipelines constructed in the United States and pose the highest-risk due to the degrading nature of iron alloys, the age of the pipelines, and pipe joints design. Aging infrastructure more often provides the challenge of “in-situ” or retro-PMI testing to confirm existing assets are fit for service.
Elemental Analysis of Pipes
Potential solutions for gathering the elemental breakdown for determining the API 5L pipe grade involves XRF and LIBS technologies.
X-ray fluorescence spectroscopy (XRF) is a non-destructive analytical technique used to determine the elemental composition of materials, including the metals from which the pipes and tanks are made. Handheld XRF analyzers work by measuring the fluorescent (or secondary) X-rays emitted from a sample when excited by a primary X-ray source. Each of the elements present in a sample produces a set of characteristic fluorescent X-rays, or “unique fingerprints”. These “fingerprints” are distinct for each element, making handheld XRF analysis an excellent tool for quantitative and qualitative measurements.
Laser Induced Breakdown Spectroscopy (LIBS) is an analytical technique used to determine the elemental composition of materials. Handheld LIBS analyzers work by using a high-focused laser to ablate the surface of a sample. A plasma is formed consisting of electronically excited atoms and ions. As these atoms decay back into their ground states, they emit characteristic wavelengths of light, or “unique fingerprints”. These “fingerprints” are distinct for each element, making handheld LIBS analysis an excellent tool for quantitative and qualitative measurements. LIBS analysis is vital to calculating carbon equivalency prior to welding to determine heat affected zone hardenability.
LIBS is an important technology used in the oil and gas industry for positive material identification of piping, pressure vessels, valves, pumps, and finished welds, or to grade unknown materials to regain traceability. (Read Is LIBS the Right Technology for Your Oil & Gas or Petrochem PMI Program?)
Using XRF + LIBS Together can also be a solution. Because oil and gas, chemical, and power generation industries use various materials ranging from carbon steel through stainless steel to super alloys, it may be appropriate to use both technologies. Many industries or third party inspection companies use these analyzers to verify the compliance of material either prior to commissioning or retroactively testing. Using handheld XRF and LIBS in tandem allows inspection companies to achieve ultimate maneuverability and mobility. Handheld XRF and Handheld LIBS are more complementary than competing techniques, each excelling in determining the composition and in verifying the grades of different families of alloys.
The mission of the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration is to “protect people and the environment by advancing the safe transportation of energy and other hazardous materials that are essential to our daily lives.”
Technologies like XRF and LIBS analysis can be part of that protection.