bluuebunny/crossref_metadata_2025_split huggingface dataset:
FRP Piping Stress Analysis Using the AutoPIPE Software With ASME NM.2 and NM.3.3
Authors: Fathi Mehdi 
Published: November 2024

Abstract
This technical paper defines a consistent approach for the pipe stress analysis of FRP piping based on the guidelines of ASME NM.2. It includes AutoPIPE setup (as an example) for FRP stress analysis. It determines the qualification criteria for FRP piping stress analysis. This method applies to the latest version of AutoPIPE and all previous software versions.
Define how to incorporate the correct allowable stress envelope, chemical resistance, cyclic service, poison ratio, thermal expansion coefficient factor, appropriate stress code, and longitudinal (axial) /circumferential (hoop)/shear modulus of elasticity. Lastly, address the proper stress intensification factor and how all the stresses must be verified.
Define how to incorporate the correct allowable stress, service temperature, environmental factor, poison ratio, thermal expansion coefficient factor, appropriate stress code, and apparent elastic modulus to meet the code cycles, as well as how it will be implemented regarding the duration of sustained loading to have a safe and standard design.
To date, none of the recognized stress analysis software like AutoPIPE and Caesar II has the ASME NM.2 in their database, but in this paper, we have tried to justify using other codes to be used and analyze the FRP/GRP pipe to meet the NM.2.
Successful On-Site Modification in CO2 Stripper of 44 Years Old Ammonia Plant
Authors: Wasi Hafiz Muhammad Zeshan , Farooq Asif , Khalid Saad 
Published: November 2024

Abstract
Pak Arab Fertilizers Plant was established in 1978 with name plate capacity 960 MTPD, KBR Technology. CO2 stripper installed originally with sieve trays. As part of Ammonia Energy Conservation project, sieve trays were replaced with packed bed design to improve stripping efficiency. Modifying 44 years old Stripper Column (∼58.5m height and Inner diameter 4.15m) has potential risks & integrity challenges considering increase in internal vessel loading by 19% from original design and addition of 07 new nozzles / manways along with resizing of 01 existing nozzle. A comprehensive assessment methodology adopted along with robust engineering reviews, Quality Assurance & Quality Control plans for safe execution. This paper focuses on the key learnings including fit for service check of design through Finite Element Analysis on existing vessel skirt for new loadings, existing civil foundation load bearing capacity check through modelling and analysis using MAT 3D, new / modified piping stress analysis using CAESAR II, Vessel design re-evaluation using ASME Sec VIII Div. I, stringent quality control methodology for repairs / alterations during execution & Post Weld Heat Treatment (PWHT) exemption for on-site weld repairs & old asset Inspection plans to monitor, maintain, and enhance safe operating life. This article will help operators to learn design consideration for old in-situ vessel modifications, Non-Destructive Examination (NDE) framework & integrity management plan to extend asset life to avoid loss of containment.
Key Learnings From Large-Bore Compressor Piping Design of a Carbon Capture System
Authors: Fernando John , Chan Luke , Kwok Henry , Yuen Simon , Roberts Steven 
Published: November 2024

Abstract
Thermo-mechanical loading and nominal pipe size are two critical considerations in the design/engineering of large-bore piping configurations, particularly when pipe diameter-to-thickness ratios exceed those commonly treated in conventional codes and standards. These considerations are further challenged when operating space is limited — which makes flexibility in the piping system more difficult to manipulate — and when rotating equipment (such as compressors) must be incorporated into the design. In the case of compressors, when the nominal pipe size is large enough that it is comparable in size to the compressor itself, the rigidity of the pipe can also produce loads on the casing that exceed the allowables. The present study outlines several important design features that should be considered when designing systems that require large-bore piping. To this end, a case study involving the retrofitting of a carbon capture and storage (CCS) facility to an existing plant is presented. In general, the retrofitting of CCS facilities is commonly constrained by the design considerations described above. Holistic design approaches that can accommodate these challenges are therefore of great importance as carbon capture initiatives become more prevalent.
Research on Effects of Surface Finishing and Mean Stress on Fatigue Lives of Notched Specimens: Test Plan and Summary of Outcomes
Authors: Asada Seiji , Hirano Akihiko , Itatani Masao , Kitamura Yoshihide , Ogawa Takeshi 
Published: November 2024

Abstract
DFC and DFC2 subcommittees in the Japan Welding Engineering Society developed a new approach of fatigue analysis method with supports from the Japanese utilities. The JSME Code Committee reviewed this fatigue analysis method and approved to incorporate it into the JSME Environmental Fatigue Evaluation Method 2022 Edition with some modifications. Also, research on effects of surface finishing and mean stress on fatigue lives of notched specimens have been followed by DFC3 and DFC4 subcommittees with supports from the Japanese utilities. In this paper, test plan and overview of the outcomes of DFC3 and DFC4 subcommittees are introduced.
Effects of surface finishing on fatigue strength and relation between a fatigue strength reduction factor and mean stress correction have been investigated using notched specimens, whose materials are carbon steel (JIS STPT370) and low alloy steel (JIS SQV2A).
The applicability of the Ksf (factor for the effect of surface finishing) equation of the JSME Environmental Fatigue Evaluation Method to notched specimens has been investigated and confirmed based on the experimental results.
The order of consideration of fatigue strength reduction factor and mean stress correction may not be considered if the Smith-Watson-Topper approach can be applied to mean stress correction. Hence, the applicability of the Smith-Watson-Topper approach with stress concentration and mean stress have been investigated and confirmed based on the experimental results.
Knowledge Graph-Based Decision Model for Gas Pipeline Emergency Response
Authors: Xu Houjia , Jian Shuai 
Published: November 2024

Abstract
Facing the problems of complexity and variability of oil and gas pipeline accidents and difficulty in giving emergency decision points efficiently, an emergency decision-making method for gas pipeline accidents based on knowledge graph was proposed. First of all, based on the evolutionary characteristics of oil and gas pipeline accidents, we built the model layer of oil and gas pipeline accident emergency knowledge map and construct the ontology model and conceptual framework of emergency knowledge map. Then, the bidirectional long and short-term memory neural network-conditional random field algorithm model was used to extract entities and relationships from 343 oil and gas pipeline accident investigation reports to populate the data in the schema layer. Then, the establishment of entity nodes and relationships was realized through the Neo4j graph database, and the oil and gas pipeline emergency response domain knowledge graph was constructed. Finally, the recommendation and ranking of emergency decision points were realized by clustering the nodes and relations of oil and gas pipeline emergency response tasks, which improves the accuracy of the emergency decision process. The method was applied to the Songyuan pipeline explosion accident in Jilin Province through example analysis. The research results show that the method realizes the rapid generation of the points of the emergency response process for newly occurred accidents. Compared with the accident investigation report, the recommended emergency response points supplement the original emergency response measures with countermeasures during the accident evolution process, combustible gas concentration monitoring, and emergency response upgrading, which further improves the emergency decision-making process. This method not only effectively solves the contradiction that the current massive data in the field of oil and gas pipeline emergency response cannot provide decision support for emergency response, but also provides a new way for emergency response decision-making in oil and gas pipeline accidents.
Analytical Assessment and Mitigation Strategies for Vibration in High-Pressure and Temperature Piping Subjected to Wall Thinning
Authors: Rehman Sameer Abdul , Alian Ahmed , Abbas Anis , Khan Qasim , Mekky Waleed 
Published: November 2024

Abstract
Critical high energy piping lines such as the Main Steam Lines of a Nuclear Power Plant are subject to high pressure, temperature, and flow rates. Operational activities on these lines can produce large dynamic loads that can cause vibration problems resulting in high stresses. High vibration in these critical lines can lead to leakages, support failures, small bore piping failures, or a main steam line break. In aging nuclear power plants, wall thinning due to corrosion can be a significant factor to consider in piping lines that are known to experience vibration.
This paper provides recommendations and mitigation strategies to reduce vibration problems in large-bore piping by assessing a typical layout of a main steam line utilizing a piping analysis software. Iterations are carried out to determine type and location of pipe supports to reduce piping code stresses and displacements. Areas of the piping known to experience wall thinning are also considered. In load cases where code stresses exceed code allowable limits, a Level 3 Fitness for Service Assessment per API 579-1/ASME FFS 2021 Code edition is performed via 3D finite element analysis.
The analysis results show that the piping stresses and displacements due to dynamic loads can be reduced effectively with the addition of supports in appropriate locations. It can also be seen that the generalized wall thickness due to aging piping lines can have a significant impact on the code stresses. Finally, modeling local thinning area in the FEA model in the Level 3 FFS assessment resulted in a less conservative analysis that allowed the corroded component to operate without repair until the next planned outage.
Analytical Modeling of Autofrettaged Cylinders With Consideration to Bauschinger Effect and Reduced Elastic Modulus
Authors: Bouzid Abdel-Hakim 
Published: November 2024

Abstract
The accurate prediction of residual stresses in autofrettaged thick cylinders is an absolute precondition for a successful design that avoids failure and predicts the fatigue life of these plastically deformed structures. The strain hardening material models during initial plastic loading and stress reversals play a major role in evaluating the residual stresses. In addition, the consideration of Bauschinger effect and the reduced elastic modulus are key parameters in the accurate prediction of the stresses specifically near the cylinder bore.
A new analytical model that considers the accurate material constitutive model defined by the material characterization conducted by Troiano and al. [1] is developed. The true strain-hardening material behavior during the initial pressure loading and subsequent stress reversals that includes Bauschinger effect and the material possible softening due to the reduced elastic modulus are taken into consideration by the developed model. The analysis is based on the Henckey deformation theory and uses the Von Mises yield criteria. The radial, hoop, longitudinal and equivalent stress results from the analytical model are compared to the ones obtained from the numerical Finite Element Method (FEM) used in conjunction with user-defined material models that includes gun material such as A723-1160, HY180 and PH 13-8Mo. The good agreement obtained shows the robustness of the developed model.
Formula-Based Thermal Stratification Analysis of Hotleg Safety Injection Piping Using Probabilistic Approach to Measured-Temperature Data
Authors: Lee Bonghee , Nam Ilkwun , Park Sangyun , Kim Hyeongwook 
Published: November 2024

Abstract
Thermal stratification could cause serious damages to both piping and its supports, and fatigue cracks in piping systems. For this reason, the U.S. Nuclear Regulatory Commission issued Bulletin 88-08 to investigate which unisolable portions of piping systems from the reactor coolant system could be potentially susceptible to thermal stratification.
The computational fluid dynamics (CFD)-based method has been widely used to predict the fluid behavior inside the piping caused by the thermal stratification. However, the results of the finite element analysis sometimes lead to different results from the actual phenomenon due to uncertainty of several variables dependent on the temperature, flow rate, and pressure required for the CFD-based thermal stratification analysis. Consequently, when performing the structural and fatigue evaluations using the CFD-based analysis results which do not sufficiently reflect the actual thermal stratification phenomenon in piping systems, the piping design may not adequately consider the effects of thermal stratification-induced stresses. The measured-temperature data from a piping system with the thermal stratification phenomenon show the actual effects of the thermal stratification in the piping system, but it may contain some uncertainty from the operating and atmospheric conditions, measurement error, etc. that affect the thermal stratification analysis results.
In this paper, a probabilistic approach has been applied to the measured-temperature data from the hotleg safety injection (HSI) piping system to account for the effects of the abovementioned uncertainty, and design temperature curves were developed based on the probabilistic approach results to perform the structural and fatigue evaluations by incorporating the effects of the thermal stratification from the HSI piping system. Also, CFD-based, finite element method (FEM)-based, and formula-based thermal stratification analyses have been performed, and their results were compared with each other to review the applicability of the formula-based analysis method to the HSI piping system. When performing the FEM-based and formula-based analysis methods, the design temperature curves determined from the results of the probabilistic approach to the measured-temperature data were used.
Risk-Informed Assessment of French Stress Corrosion Cracking Operational Experience Relative to the Fleet of Pressurized Water Reactors in the United States of America
Authors: Rudland David , Leech Matthew , Homiack Matthew , Nellis Christopher 
Published: November 2024

Abstract
During a typical inservice inspection on October 21, 2021, at Civaux Unit 1 (a 4-loop, 1450 MW pressurized water reactor (PWR)) in France, Électricité de France (EDF) found circumferential cracking at several locations near an elbow in a non-isolable section of piping in the emergency core cooling system (ECCS). Through destructive examination, EDF determined that the root cause of the cracking was intergranular stress corrosion cracking (IGSCC) caused by stresses associated with thermal stratification. Weld residual stress (WRS) may have also played a role in the cracking. After discovery of this cracking, EDF expanded its inspections to other similarly designed plants and identified many cracks in similar locations in the safety injection and residual heat removal systems. The French response to this operational experience (OE) is still ongoing.
The U.S. industry responded to this OE by developing a focus group organized by the Pressurized Water Reactor Owners Group (PWROG) and the Electric Power Research Institute (EPRI). This focus group assessed applicability of the OE to the U.S. fleet of PWRs and the associated safety implications. While the industry focus group found no direct evidence of this type of cracking in the U.S. PWR fleet and, therefore, no safety issues, it did recommend a modification to inspection methods to better identify IGSCC in these welds. In parallel, the U.S. Nuclear Regulatory Commission (NRC) staff conducted both qualitative and quantitative analyses using a risk-informed approach to assess the safety significance of the OE and determine what regulatory actions, if any, were appropriate. This paper discusses the NRC staff’s results, which consisted of detailed probabilistic fracture mechanics (PFM) analyses to estimate loss of coolant accident frequencies that were then used in a probabilistic risk assessment (PRA) to determine the impact of the OE (assuming it occurs) on the core damage frequencies of the U.S. PWR fleet. The results suggest that the risks to U.S. PWRs are low and that the industry-planned inspection method modifications can maintain adequate safety margins and performance monitoring.
On the Required Distance to Major Structural Discontinuity From Local Metal Loss Area
Authors: Ishizaki Yoichi , Ameya Hiroyasu 
Published: November 2024

Abstract
API 579-1/ASME FFS-1 Fitness for Service Part 5 local metal loss Level 2 assessment requires a sufficient distance between local metal loss area and neighboring major structural discontinuity based on S.Timoshenko’s model [1] [2]. The model assumed a concentrated force and moments on a cylindrical shell. A sufficient distance to settle down the bending moment from the point was evaluated.
Occasionally, a flaw is observed around a major structural discontinuity, and the required distance limits the application of Lv.2 assessment. While the model would be well applicable for piping nozzles and supporting attachments that takes external force and moment, some of those limiting components, such as stiffeners, vessel heads and manway nozzles in kind, are not taking any external forces and moments. They might affect to the local metal loss area in a different manner than piping nozzles and such. In 2023 ASME PVP, S.Bouse et al. [2] discussed the effect of ellipsoidal head and hemisphere head in their paper ; PVP 2023-106371 Re-Evaluating the Minimum Required Distance Between Local Thin Area In Cylinder and an Ellipsoidal Head. The conclusion was that ellipsoidal heads was beneficial for local metal loss assessment based on FEM model data. The outcome is incorporated in 2021 version of API579-1/ASME FFS-1 Fitness-For-Service, table 4.2 [3].
To discuss which type of “Major Structural Discontinuity” would be beneficial for local metal loss assessments one step further, it would be important to consider the significance of Folias factor, Mt, and surface correction factor, Ms, of current API579-1/ASME FFS-1 Part 5 assessment. As discussed in our previous paper [4], authors reorganized the significance and derivation of Mt and Ms. Based on the model of Ms, the pressure load working on remaining ligament underneath flaw was equal to flow stress level and the surplus pressure load was traveling to side ligaments. The idea of model indicated RSF would be increased according to the increase of side ligament cross section. If this was true, stiffening ring, manway nozzles and flanges would be a good candidate to exempt from current “Distance to Major Structural Discontinuity”, Lmsd, requirement [3] in addition to ellipsoidal head. Because those components simply exist on cylindrical shells provides extra cross section without any significant external forces and moments on cylindrical shell unlike piping nozzles.
In this paper, using FEM models of stiffening rings and ellipsoidal heads as example cases, an interaction mechanism between “Major Structural Discontinuity” and flaw will be discussed considering the concept of Ms model. This would contribute to enhance the “distance to major structural discontinuity” criteria discussion.
A Comparative Study on Creep-Fatigue Evaluation Methodologies For Natrium™ Reactor Internal Components Using Elastic and Inelastic Analysis
Authors: Xu Heqin , Riordan Tom , Bhuiyan Shafiq , Cohen Michael 
Published: November 2024

Abstract
Per ASME Code Section III Div. 5, design of a Class A component for elevated temperature service must meet the functional requirements specified in the Design Specifications (NCA-3211.19) to be acceptable. Also it needs to satisfy the requirements for a design by analysis, either in HBB-3200 or in the Design Rules for components, while under the loadings described in HBB-3111.2 and the Design Specifications; and satisfies the general design rules of HBB-3130 and the applicable design rules for components. The creep-fatigue assessment is part of the Code requirements to meet the strain and deformation limits for a design by analysis for a Class A metallic pressure boundary component as required in HBB-3200, and a Class SM metallic core support structure as required by HGB-3200. As suggested by the Code, the analysis can be either elastic analysis, elastic perfectly plastic analysis, or inelastic analysis. Although the inelastic analysis is more complicated than the elastic analysis method considering the required time-dependent material properties to account for plasticity and creep, the elastic analysis method has more complicated rules than the inelastic analysis since the elastic strain range must be adjusted to account for plasticity and creep. The adjustments are usually over-conservative that makes it difficult to pass the required limits under most design situations by elastic analysis method. This paper compares the creep-fatigue evaluation procedures and results using elastic analysis method and inelastic analysis method, emphasizing the safety margin each analysis method can achieve.
Experimental and Numerical Analyses for the Evaluation of Heat Fluxes of a Fire Reference Test
Authors: Gleim Tobias , Feldkamp Martin , Quercetti Thomas , Wille Frank 
Published: November 2024

Abstract
Packages for the transport of high-level radioactive material are designed to endure severe accidents. To obtain approval, these transport packages must adhere to the specification-based criteria of the IAEA SSR-6 [1]. To ensure compliance with these requirements, specific mechanical and thermal tests need to be appointed with respect to the package type. Typically, IAEA SSR-6 [1] prescribes mechanical tests followed by a thermal fire test as part of a cumulative test sequence. To approve the fire test, BAM uses a reference package representing the original package in its outer geometry for characterizing the actual fire and its impact on the package. This serves a dual purpose: it allows the precise adjustment of experimental parameters for the package design to be approved, and it provides input parameters for thermomechanical simulations, cf. [2]. With the help of this methodology for characterizing boundary conditions of the package, temperature evolutions within the reference package can be studied in a Finite-Element Analyses (FEA). This helps to compare the experiments with the numerical simulations on the case of the reference package, but also serves at the same time for preliminary simulations with the package design to be approved.
The thermal test consists of a 30-minute fully engulfing 800°C pool fire or an equally severe fire, e.g. a propane gas fire. The fire reference test is performed prior to the regulatory fire test with the package design to be approved. The fire reference package in the described case is a closed sheet 316L steel cylinder with a wall thickness of 10 mm, a length of 182 mm, and a diameter of 102 mm. The package was instrumented with thermocouples and filled with heat resistant insulating material.