SI Presents at PRCI AGA & ASME

Pipeline Integrity Activity and Plans for 2022

Authors: Scott Riccardella and Andy Jensen

2021 marked another successful year for the Structural Integrity (SI) Oil & Gas team with several exciting pipeline integrity projects, industry presentations, training events and research programs.  Some of the key highlights include:

  • Continued regulatory consulting support of new pipeline safety regulation (known as Mega-Rule 1 or RIN 1) for nearly all our gas transmission pipeline clients.
  • Commencement of a systemwide pipeline integrity project to evaluate the impact to pipeline safety and reliability from blending hydrogen with natural gas (at various blend levels) for one of the largest U.S. gas pipeline companies.
  • Several industry presentations and training seminars on fracture mechanics evaluation of crack and crack-like defects in support of Predicted Failure Pressure (PFP) Analysis and Engineering Critical Assessments (ECA).
  • Completion of a PRCI study on state-of-the-art technology and a technology benchmark evaluation of X-Ray Computed Tomography to characterize Stress Corrosion Cracking (SCC) on full circumferential samples.
  • Development of a Neural Network algorithm and application of Probabilistic Fracture Mechanics to provide insight on the risk of SCC for a large interstate natural gas pipeline operator.
  • Development of an alternative sampling program for Material Verification when using In-Line Inspection tools including development of regulatory submittals.

2022 is also shaping up to be a similarly busy and exciting year.  Below are some of the events, conferences and presentations SI has currently planned (most of which represent ongoing or recently completed projects):

  • At the PRCI Research Exchange on March 8th in Orlando, FL, SI is presenting on two recent projects:

Insights in the Evaluation of Selective Seam Weld Corrosion

This paper will review a statistical analysis of ERW Fracture Toughness and specific challenges in evaluating Selective Seam Weld Corrosion (SSWC).  It also reviews the results of an engineering critical assessment performed on a pipeline system in which several SSWC defects were identified. Fracture Toughness Testing and Finite Element Modeling were performed to develop insights that were used to support Predicted Failure Pressure analysis and subsequent prioritization and remediation activities.

Title: Evaluation of X-Ray Computed Tomography (XRCT) for Pipeline Reference Sample Characterization

This presentation will review the feasibility of utilizing XRCT for nondestructively characterizing full-circumference pipeline reference samples for subsequent qualification and performance improvement of inline inspection and in-the-ditch nondestructive evaluation technologies, procedures, and personnel. This presentation will cover the state-of-the-art in XRCT, reviewing theoretical and practical concepts, as well as empirical performance data, that were evaluated and analyzed to determine the feasibility of using XRCT for this application.

  • SI has two papers that will be presented at the American Gas Association – Operations Conference the week of May 2nd in New Orleans, LA:

Alternative MV Sampling Program

SI will present technical justification in support of PHMSA notification with regards to the following:

  • Alternative sampling for Material Verification Program (per §192.607).
  • Expanded MV Sampling Program that will achieve a minimum 95% confidence level when material inconsistencies are identified.

A Framework for Evaluating Hydrogen Blending in Natural Gas Transmission Pipelines

Operators are establishing programs to blend hydrogen with natural gas.  Structural Integrity (SI) is supporting a local distribution company to ensure safe and reliable blending and transportation in existing pipeline infrastructure.  SI will present a reliability framework to identify pipelines that are best suited at different H2 blend levels.

  • SI will present at the 2022 ASME – International Pipeline Conference on the following topic:

Probabilistic Analysis Applied to the Risk of SCC Failure

This paper will discuss a model developed and applied to evaluate the probability of Stress Corrosion Cracking (SCC) failure in a large gas pipeline system spanning approximately 5,600 miles.  A machine learning algorithm (neural network) was applied to the system, which has experienced over 500 prior instances of SCC.  Subject matter experts were interviewed to help identify key system factors that contributed to the prevalence of SCC and these factors were incorporated in the neural network algorithm. Key factors such as coating type, vintage, operating stress as a percentage of SMYS, distance to compressor station, and seam type were evaluated in the model for correlation with SCC occurrence.  A Bayesian analysis was applied to ensure the model aligned with the prevalence of SCC.  A Probabilistic Fracture Mechanics (PFM) model was then applied to relate the probability of SCC existing to the probability of rupture.

Alumni Achievement Award

Structural Integrity’s Own HonoredGordon NACE 2021 | Corrosion in the Nuclear Power Industry” for ASM Handbook

Awarded to an alumnus/a for exceptional accomplishment and leadership in the nominee’s professional or vocational field, which brings distinction to themselves and honor to the university. The contribution(s) need not be publicly renowned but should represent important creative effort or accomplishment with significant impact and value.

Barry Gordon is one of the country’s leading experts in corrosion and materials issues in the nuclear power industry.  Upon completing his undergraduate and graduate degree in metallurgy and materials science, he began his career with Westinghouse Electric’s Bettis Atomic Power Laboratory before joining GE Nuclear Energy in San Jose. Currently, Barry is an associate with Structural Integrity Associates, Inc. His professional accomplishments include four patents, more than 85 technical papers and reports, a PE in Corrosion Engineering and a Corrosion Society Fellow. He has served as an expert witness before the Advisory Committee on Reactor Safeguards and Atomic Safety Licensing Board. He also chaired and co-authored “Corrosion in the Nuclear Power Industry” for ASM Handbook, Volume 13C.

Active outside of his professional pursuits, Barry was the president of the Los Gatos Bicycle Racing Club, principal timpanist with the Saratoga Symphony. Barry’s relationship with his alma mater includes supporting two scholarships at CMU, serving as the San Jose chairperson of the CMU Admission Council and being an active member of the Andrew Carnegie Society and a lifetime member of the Order of the May.

Material Verification for Oil and Gas Clients Pipeline Integrity Solutions

News & Views, Volume 50 | Material Verification for Oil and Gas Clients


By:  Scott Riccardella and Roger Royer

Material Verification for Oil and Gas Clients Pipeline Integrity SolutionsOn October 1, 2019, the Pipeline and Hazardous Materials Safety Administration (PHMSA) published amendments to 49 CFR Parts 191 and 192 in the Federal Register, issuing Part 1 of the Gas Transmission Mega-Rule or “Mega-Rule 1”.  In advance of Mega-Rule 1, SI developed field protocol and supported leading industry research institutes in validating in-situ Material Verification (MV) methodologies.  SI has continued to provide MV consulting support to our clients in response to Mega-Rule 1, ranging from program development and implementation to in-situ field data collection and analysis. 

Various sections of Mega-Rule 1 require operators of natural gas transmission pipelines to ensure adequate Traceable, Verifiable, and Complete (TV&C) material records or implement a MV Program to confirm specific pipeline attributes including diameter, wall thickness, seam type, and grade. Operators are now required to define sampling programs and perform destructive (laboratory) or non-destructive testing to capture this information and take additional actions when inconsistent results are identified until a confidence level of 95% is achieved. Opportunistic sampling per population is required until completion of testing of one excavation per mile (rounded up to the nearest whole number). 


SI FatiguePRO for Hydrogen Fueling Station Assets - Vessel Life Cycle Management

News & Views, Volume 50 | SI FatiguePRO for Hydrogen Fueling Station Assets


By:  Erick Ritter and Daniel Peters

SI FatiguePRO for Hydrogen Fueling Station Assets - Vessel Life Cycle ManagementInitial introduction of many of the hydrogen fueling stations to support this rapidly growing demand were installed around 2010. There were many designs of cylinders developed and installed at that time, many with known limitations on the life of the equipment due to the high pressures involved and cyclic fatigue crack growth issues due to hydrogen embrittlement.  The designs were often kept relatively simple to lower their costs often with little or no considerations for in-service inspection or potential end of life considerations.  Others involved innovative designs with reinforcing wrapping to try to enhance the life of the vessels, but by doing so, these designs limited the access to the main cylinder wall for in-service inspection. 

Many of these vessels are now reaching or passing the design life established by ASME.  This is resulting in problems for operators of this equipment as some jurisdictions will not allow the vessels to operate beyond the design life without inspection or re-rating of the vessels to extend the fatigue life.  SI’s FatiguePRO is a commercial software solution which has been addressing this exact concern for over 25 years.


Reactor Vessel Integrity - Fracture Toughness Criteria

News & Views, Volume 50 | Reactor Vessel Integrity


By:  Tim Griesbach and Dan Denis

Reactor Vessel Integrity - Fracture Toughness CriteriaThe integrity of the nuclear reactor pressure vessel is critical to plant safety.  A failure of the vessel is beyond the design basis.  Therefore, the design requirements for vessels have significant margins to prevent brittle or ductile failure under all anticipated operating conditions.  The early vessels in the U.S. were designed to meet Section VIII of the ASME Boiler and Pressure Vessel Code and later Section III.  ASME Section III included requirements for more detailed design stress analyses also included a fracture mechanics approach to establish operating pressure-temperature heatup and cooldown curves and to assure adequate margins of safety against brittle or ductile failure incorporating the nil-ductility reference temperature index, RTNDT. This index is correlated to the material reference fracture toughness, KIC or KIa. 

Radiation embrittlement is a known degradation mechanism in ferritic steels, and the beltline region of reactor pressure vessels is particularly susceptible to irradiation damage.  To predict the level of embrittlement in a reactor pressure vessel, trend curve prediction methods are used for projecting the shift in RTNDT as a function of material chemistry and fluence at the vessel wall.  Revision 2 of this Regulatory Guide is being used by all plants for predicting RTNDT shift in determining heatup and cooldown limits and hydrostatic test limits.


TRU Compliance Equipment Testing Project Equipment Testing and Certification to Assess Risk

News & Views, Volume 50 | TRU Compliance Equipment Testing Project


By:  Katie Braman

Using a risk-based approach derived from various seismic standards from the Institute of Electrical and Electronics Engineers, TRU and BC Hydro will develop a synthetic test motion in three axes, mount the equipment on a triaxial shake table at TRU’s testing partner’s facility, and test at increasing levels until various levels of damage are observed.

TRU Compliance Equipment Testing Project Equipment Testing and Certification to Assess RiskTRU Compliance, the accredited product certification body of Structural Integrity Associates, has been awarded a contract to assist BC Hydro in qualifying and better understanding the seismic vulnerability of critical equipment used to control its spillway gates.  As part of the larger efforts to seismically upgrade the John Hart, Ladore, and Strathcona dams along the Campbell River system on Vancouver Island, British Columbia, BC Hydro is procuring equipment that allows precise flow control of the water going over the spillway.  Reliable equipment is needed to prevent possible overtopping or having uncontrolled water flow through the spillway.


Porting SI's ANACAP Concrete Model into LS-DYNA Advanced Structural Analysis

News & Views, Volume 50 | Porting SI’s ANACAP Concrete Model into LS-DYNA


By: Livia Mello and Shari Day

Porting SI's ANACAP Concrete Model into LS-DYNA Advanced Structural AnalysisOne of Structural Integrity Associates’ (SI) strengths is combining state-of-the-art software with material science expertise to solve difficult structural and mechanical problems. A notable example in recent years is the Aircraft Impact Analysis (AIA) performed by SI for NuScale Power, using the ANACAP concrete material model. With SI’s support, NuScale’s Small Modular Reactor (SMR) building design passed NRC’s comprehensive inspection, bringing NuScale’s SMR technology one step closer to market [N&V Vol. 47 p. 5].

SI’s success in AIA is due not only to our team’s capabilities but also due to the capabilities of our proprietary concrete constitutive model, ANACAP, developed by Joe Rashid, Robert Dunham, and Randy James of ANATECH, now part of SI. Modeling reinforced concrete, which is both nonhomogeneous and anisotropic, is often a challenge in advanced structural analysis. However, ANACAP has a long track record of accurately capturing nonlinear concrete response in structural systems subjected to static, impact, and seismic loads. Its application goes beyond AIA; it has also been utilized in several of SI’s commercial building, bridge infrastructure, nuclear plant, and hydroelectric facility projects.

ANACAP has the ability to account for cyclic degradation, multi-axial cracking, load-rate effects, aging, creep, shrinkage, crushing, confinement, concrete-reinforcement interaction, and high-temperature softening behavior. The combination of these features results in an exceptional representation of concrete intricate behavior. It also leads to more accurate results when compared to standard finite element “built-in” concrete material libraries, all the while being implemented within the same standard finite element formulation.


Oil and Gas Pipeline Intel - Industry Regulation Insights

News & Views, Volume 50 | Oil and Gas Pipeline Intel

PRCI June Technical Committee MeetingsOil and Gas Pipeline Intel - Industry Regulation Insights

Structural Integrity Associates (SI) recently attended the PRCI June 2021 Technical Committee (TC) Meetings. SI is also planning to support the upcoming PRCI NDE workshop scheduled for October 2021 as well as future committee meetings. SI will continue to engage and support industry with PRCI.  As a researcher for PRCI, SI is pleased to support industry in the development and evaluation of new technology and methods that can enhance pipeline safety and reliability.  SI continues to support the development of new tools and analytical methods to help advance crack management, material verification, NDE inspections, and pipeline integrity management and share our experience with PRCI and industry.  Please contact us with any questions regarding our involvement or how SI can support your pipeline safety and reliability objectives.

SI Presenting at the 2021 AGA Operations Conference on “Responding to Cracks and Crack-Like Defects for Mega-Rule 1”.

Structural Integrity is pleased to partner with Duke Energy to present on Mega-Rule 1 requirements for the Analysis of Predicted Failure Pressure (192.712).  Procedures, tools and practical applications will be presented along with specific case studies.  In addition, methods to address additional requirements for evaluating cyclic fatigue will also be presented.  This presentation will be at the AGA Fall Operations Conference in Orlando, FL scheduled for October 6, 2021 at 10:45 AM in the Integrity Management track. Additional detail on the event can be found at the following site:

Materials Laboratory Case Study #6 | Manufacturing – Supply Chain Upsets News

Manufacturing Supply Chain Upsets


A supplier of electromagnetic interference (EMI) components noticed that one of their manufacturer’s components was not performing as well as similar components had previously.  The supplier had several theories on the make-up of the component and asked SI to investigate and confirm the material constituents as well as their distribution across the thickness.

A small, coiled metallic sample, representative of the latest batch of material received from the manufacturer, was brought to SI’s Materials Laboratory for analysis. The goal of the analysis was to identify the elemental constituents present to help assess composition and also the distribution of the elements through the thickness. The sample was cross-sectioned and examined and documented in a scanning electron microscope (SEM) as shown in Figure 1. Using backscattered electrons (which help distinguish compositional differences) it was clear that the surfaces had a unique composition (dark grey) when compared to the base substrate (light grey). 

An elemental map of the cross-section was captured using energy dispersive X-ray spectroscopy (EDS) to identify the elements present across the thickness. The elemental map is provided in Figure 2 and the EDS analysis results are provided in Table 1. The sample was confirmed to comprise mostly of titanium and aluminum, which was expected, but was found to be titanium substrate with cladding of aluminum and silver on the surfaces .

Utilizing this information the supplier was able to engage with the manufacturer to help ensure that the material was being manufactured in a way suitable for the given end-use.

Figure 1. As received image of the metallic component and overall micrograph of the component cross-section red arrows show the cross-section location | Manufacturing – Supply Chain Upsets

Figure 1. As received image of the metallic component and overall micrograph of the component cross-section red arrows show the cross-section location

Figure 2. Maps showing elemental distribution through the component cross section | Manufacturing – Supply Chain Upsets

Figure 2. Maps showing elemental distribution through the component cross section

Element Surface A Base Substrate Surface B
Carbon 10.2 7.2
Oxygen 1.2 1.6
Sodium 0.7 0.7
Magnesium 0.8 1.1
Aluminum 76.5 0.5 81.8
Silicon 0.3 0.5 0.4
Calcium 0.2 0.3
Titanium 8.4 98.7 4.9
Iron 0.1 0.1 0.5
Silver 1.8 1.5

Elemental mapping is based on compiling extremely specific elemental composition data across an area of a sample. This is typically done in an SEM using EDS analysis. A high resolution image of the area of interest is collected along with the EDS data, and the two are correlated.

[1] The sample was prepared in a carbon-based mounting medium for use in the SEM, so much of the carbon is from sample preparation.

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Materials Laboratory Case Study #5 | Process Upsets – Condition Analysis

Process Upsets – Condition Analysis


A filter was removed from a stator cooling system after pressure differential sensors indicated it may be blocked. The filter was submitted to SI’s Materials Laboratory for analysis to help identify the material blocking it.

Figure 1. The filter shown in the as-received condition| Process Upsets – Condition Analysis
Figure 1. The filter shown in the as-received condition

Figure 2. The yellow color is the original appearance of the filter | Process Upsets – Condition Analysis
Figure 2. The yellow color is the original appearance of the filter

The filter was visually examined and documented in the as-received condition as shown in Figure 1. The submitted sample had a perforated plastic shell that covered an inner filter. The outer plastic was removed to provide access to the filter underneath. Figure 2 shows close images of the filter, which was yellowish-white with much of its surface covered in gray colored debris/deposit.

Figure 3. SEM images of material removed directly from the filter (left) and particles from the evaporated MEK (right) B | Process Upsets – Condition Analysis

Figure 3. SEM images of material removed directly from the filter (left) and particles from the evaporated MEK (right) B

A portion of the filter was scraped to remove the deposits. Another portion of the filter was removed and soaked in Methyl Ethyl Ketone (MEK) to remove the debris present on the filter. The solvent evaporated and the remaining particles were collected. Both samples were analyzed in a scanning electron microscope using energy dispersive X-ray Spectroscopy (EDS) to identify the elements present. The results are provided in Table 1. The results indicate that the filter debris was primarily copper oxide. Plant personnel reported that copper contamination could be occurring in the system, so these findings appeared to be consistent with plant information. With their suspicions confirmed, plant personnel were able to move forward with mitigation steps for keeping the filters from becoming blocked.

Element Material Removed from Filer Particles from MEK Wash
Carbon 4.9 ND
Oxygen 13.4 18.5
Aluminum 0.2 1.3
Silicon 0.4 4.2
Sulfur 0.1 0.3
Chlorine 0.1 0.1
Chromium 0.3 1.6
Iron 0.4 4.0
Nickel ND 0.4
Copper 79.7 68.4
Tin 0.4 1.3

Table 1. Filter Material EDS Analysis Results (wt.%)

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