MAOP validation - traceable, verifiable and complete illustration

When assisting with the materials verification stage of MAOP validation, SKW’s team completes a comprehensive records review to ensure there are reliable, traceable, verifiable and complete records for all pipelines in HCAs (high consequence areas), including the mill test report, pipe tallies and as-built tallies. The proposed rulemaking would expand the number of areas subject to this review.

On April 8, 2016, the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) issued a notice of proposed rulemaking (NPRM) published in Federal Register Vol. 81 No. 68 that outlines significant changes to the Pipeline Safety Regulations to increase the safety of onshore natural gas transmission and gathering pipelines across the country.

Shafer, Kline & Warren’s (SKW) Team Leader of Integrity Management Daniel Thayer and his team provide comprehensive project management, plan development, integrity assessment and hydrostatic testing to help pipeline owners and operators ensure pipeline safety and regulatory compliance. Thayer explains that understanding the forthcoming changes and how to address them proactively should be an essential part of operations and maintenance plans moving forward.

One of the most significant areas of change that will have far-reaching impacts on owners and operators focuses on maximum allowable operating pressure (MAOP) and pipeline material verification.

When approaching MAOP validation, Thayer breaks it into a two-part process. The first step is materials validation as part of 49 CFR Part 192.  For this, a design formula is used that accounts for the pipeline’s specified minimum yield strength (SMYS), wall thickness and diameter multiplied by the class location factor, which is based on population density and the number of residents living within close proximity of the pipeline. PHMSA’s Advisory Bulletin AD-12-06 published in Federal Register Vol. 77 No 88, on May 7, 2012 reminded operators to verify their records are traceable, verifiable and complete.

During the second step, hydrostatic testing or other approved methods must be used to validate the lengths of pipe that have missing information.

“During the first step we go through the records to identify gaps, and show that the parameters used in the design formula were accurate and support the pipeline’s current MAOP,” said Thayer. “The second step is really about proving the pipe through a PHMSA-approved method, the most common of which is hydrostatic testing.”

Currently, pipelines that were installed before 1970 can rely upon a grandfather clause that allows operation of the pipeline at the highest pressure in the five years prior to 1970 without hydrostatic test records.  In the NPRM, it is recommended that the grandfather clause be eliminated. According to PHMSA, about 60 percent of natural gas transmission pipeline mileage was installed prior to 1970.

“The operating pressures that these pipelines are operating at under the grandfather clause may not have ever been substantiated,” said Thayer. “If that clause disappears as PHMSA is recommending, it will affect a large number of owners and operators who are going to need to prove these pipelines through hydrostatic testing or other methods approved by PHMSA.”

Another change recommended is the definition of moderate consequence areas (MCAs). Pipelines in the newly defined MCAs would be required to complete integrity assessments in addition to the high consequence areas (HCA). HCAs are currently subject to comprehensive integrity management regulations, and are defined as pipeline segments with 20 or more buildings intended for occupancy within the impact radius of the pipeline, which is calculated based on the pipeline’s diameter and MAOP. MCAs would be calculated using the same formula except the threshold would be five buildings, rather than 20.

According to the NPRM, “The intention is that any pipeline location at which persons are normally expected to be located would be afforded extra safety protections.” This would include periodic integrity assessment, reliable, traceable, verifiable and complete materials documentation, and MAOP verification.

“We have extensive experience helping operators through this process,” said Thayer. “We always begin the process with a comprehensive review of construction job books to verify that they have the documentation to substantiate the pressure at which the pipeline is operating. We then perform a gap analysis to determine what documents are missing, and come up with a strategic plan to bring the pipelines into compliance, prioritized based on risk level.”

The final two areas of regulatory expansion related to MAOP are the recommended addition of a spike test as part of the hydrostatic testing requirement and the application of transmission line MAOP regulations to certain gathering lines.

“The impacts of these regulations are far reaching, and, if enacted, may tax the capabilities of the integrity management industry as we work to meet the needs of pipeline operators,” said Thayer. “There will likely be a cost to waiting. As the demand for hydrotests and records validation increases, so may the cost of these services. By taking a proactive approach to these proposed changes, operators will avoid these market pressures while protecting themselves against regulatory enforcement as well as dangerous, costly pipeline incidents.”

Dan Thayer

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