Maximum Allowable Operating Pressure (MAOP) Archives

News & Views, Volume 49 | Digital Elevation Modeling: Support Pressure Tests Records and Reduce MAOP Reconfirmation Costs

April 20, 2021/in Bruce Paskett, Eric Elder, News and Views, Oil and Gas Pipeline, Scott Riccardella/by Structural Integrity

By: Scott Riccardella, Bruce Paskett, and Eric Elder

§ 192.624(a)(1) of the Mega-Rule 1 requires MAOP Reconfirmation for steel transmission pipe segments if records necessary to establish the MAOP in accordance with § 192.619(a)(2) (e.g. pressure test), including records required by § 192.517(a), are not traceable, verifiable, and complete and the pipeline is located in a high consequence area (HCA) or a Class 3 or Class 4 location.

Part 192, Section 192.517(a) requires that natural gas pipeline operators shall make and retain, for the useful life of the pipeline, a record of the following information for any Subpart J Pressure Test (PT):

The operator’s name, the name of the operator’s employee responsible for making the test, and the name of any test company used,
Test medium used,
Test pressur,
Test duration,Pressure recording charts, or other record of pressure readings.
Elevation variations, whenever significant for the particular test, and
Leaks and failures noted and their disposition.

News & Views, Volume 45 | Gas Pipeline Safety Regulation Update

January 1, 2019/in Bruce Paskett, Eric Fisette, Mega-Rule, News and Views, Oil and Gas Pipeline, Scott Riccardella/by Structural Integrity

By: Scott Riccardella. Erica Fisette, and Bruce Paskett

Update on the Safety of Gas Transmission and Gathering Pipelines Rulemaking (known as the Mega-Rule)
Structural Integrity (SI) personnel have had significant involvement in the Gas Pipeline Advisory Group (GPAC) meetings focused on consideration of the proposed pipeline safety rule titled “Safety of Gas Transmission and Gathering Pipelines” (Notice of Proposed Rule Making April 8, 2016). The meetings produced several recommendations to the Pipeline and Hazardous Materials Safety Administration (PHMSA) that are likely to be included in the Final Rule. A key outcome of these meetings was that PHMSA has decided the Final Rule will be split into three sub-rule packages that will all be final rules to facilitate the rulemaking process:

Maximum Allowable Operating Pressure (MAOP) reconfirmation, Material Verification, Expansion of Integrity Management Assessments Outside of High Consequence Areas (HCAs) and other related issues,
Repair Criteria, Inspections Following Extreme Weather Events, Corrosion Control improvements, Management of Change; and
Expansion of Part 192 regulations to include additional Gas Gathering Lines.

News & Views, Volume 44 | Update on Proposed Safety of Gas Transmission and Gathering Pipeline Regulation

April 27, 2018/in Bruce Paskett, Eric Fisette, News and Views, Oil and Gas Pipeline, Scott Riccardella/by Structural Integrity

By: Scott Riccardella, Erica Fisette, and Bruce Paskett

Structural Integrity (SI) has significant depth and expertise in current pipeline safety regulations and dedicates substantial resources to ensure a comprehensive understanding of proposed pipeline safety regulations. Using the most current insights relative to upcoming regulations, Structural Integrity guides our clients with strategic direction to best position their pipeline safety programs to comply with the new regulations. Structural Integrity takes a proactive role in attending key Pipeline and Hazardous Materials Safety Administration (PHMSA) meetings such as the Gas Pipeline Advisory Committee (GPAC) meetings as well as supporting the rulemaking efforts of the American Gas Association (AGA), Interstate Natural Gas Association of America (INGAA), Pipeline Research Council International (PRCI) and other key associations.

The GPAC is a statutorily mandated Committee that advises PHMSA on proposed gas pipeline safety standards and regulations. The Committee consist of members from Federal and State governments (PHMSA and National Association of Pipeline Safety Representatives or NAPSR), the regulated industry, and the general public. The Committee is responsible for reviewing the technical feasibility, reasonableness, cost-effectiveness, and practicability of proposed standards and regulations relative to pipeline safety. The goal of the Committee is to provide recommended revisions and/or actions in response to standards and/or regulations proposed by the Federal Department of Transportation (DOT)/ PHMSA.

News & Views, Volume 43 | In-Line Inspection – An Improvement Over Pressure Testing for Pipeline Integrity Management

October 5, 2017/in News and Views, Non-Destructive Evaluation, Oil and Gas Pipeline/by Structural Integrity

By: Scott Riccardella, Dilip Dedhia, and Peter Riccardella

Structural Integrity recently performed probabilistic fracture mechanics (PFM) analysis of a gas transmission pipeline for a major U.S. operator. The analysis yielded interesting insights in several areas:

Pressure Testing versus In-Line Inspection
Pressure testing has long been considered the gold standard for assuring pipeline integrity. By testing at a factor (e.g., 1.25x or 1.5x) above the Maximum Allowable Operating Pressure (MAOP), any size critical flaws in the line would fail at this pressure level and are thus removed prior to future service. Subcritical flaws that remain after the test will be smaller than the critical flaw sizes during operation, and thus can be assumed to have some margin for growth before they become critical in service. Flaw growth rates can be calculated based on operational and environmental factors to establish a reassessment interval for future testing or inspections.

News & Views, Volume 43 | A Strategic Approach for Completing Engineering Critical Assessments of Oil and Gas Transmission Pipelines

October 5, 2017/in News and Views, Oil and Gas Pipeline, Scott Riccardella, Steven Biles/by Structural Integrity

By: Scott Riccardella and Steven Biles

Regulatory Overview
In January 2012, the Pipeline Safety, Regulatory Certainty, and Job Creation Act of 2011 was signed into law directing PHMSA to take steps to further assure the safety of pipeline infrastructure. PHMSA issued the related Notice of Proposed Rulemaking (NPRM) for Safety of Gas Transmission and Gathering Pipelines on April 8, 2016. Included in the NPRM were significant mandates regarding:

Verification of Pipeline Material (§192.607); and
Maximum Allowable Operating Pressure (MAOP) Verification or “Determination” (§192.624)

The NPRM proposes requirements for operators to verify the MAOP of a gas transmission pipeline when:

The pipeline has experienced an in-service incident (as defined by §191.3) due to select causes¹ in a High Consequence Area (HCA), “piggable” Moderate Consequence Area (MCA), or Class 3 or 4 location since its last successful pressure test
The pipeline lacks Traceable, Verifiable, and Complete pressure test records for HCAs or Class 3 or 4 locations
The pipeline MAOP was established by the grandfather clause (§192.619 (a)(3)) for HCAs, “piggable” MCAs, or Class 3 or 4 locations.

To verify the MAOP of a pipeline, the NPRM provides the following options:

Method 1: Pressure Test
Method 2: Pressure Reduction
Method 3: Engineering Critical Assessment (ECA)
Method 4: Pipe Replacement
Method 5: Pressure Reduction for segments with small potential impact radius (PIR) & diameter
Method 6: Use Alternative Technology

The ECA Approach
Per the NPRM, Method 3 (ECA) is defined as an analysis, based on fracture mechanics principles, material properties, operating history, operational environment, in-service degradation, possible failure mechanisms, initial and final defect sizes, and usage of future operating and maintenance procedures to determine maximum tolerable sizes for imperfections.

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