Material Requirements for Long-Life Pressure Vessels

1964 ◽  
Vol 86 (4) ◽  
pp. 403-409 ◽  
Author(s):  
B. F. Langer ◽  
W. L. Harding
Keyword(s):  
Plastic Deformation ◽  
Brittle Fracture ◽  
Creep Deformation ◽  
Pressure Vessel ◽  
Material Properties ◽  
Failure Modes ◽  
Pressure Vessels ◽  
Additional Information ◽  
Modes Of Failure ◽  
Long Life

In this paper the authors consider the various possible modes of failure of a pressure vessel intended for long service and show which material properties are of significance in preventing them. The failure modes discussed are (a) plastic deformation and bursting; (b) brittle fracture; (c) fatigue failure; (d) creep deformation and creep rupture; (e) corrosion. The need for additional information in several areas is also noted.

Design by Analysis of GFRP/CFRP Composite Pressure Vessels

2018 ◽  
Author(s):  
Martin Muscat ◽  
Duncan Camilleri ◽  
Brian Ellul
Keyword(s):  
Pressure Vessel ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Pressure Vessels ◽  
Design Methods ◽  
Damage Mechanisms ◽  
Modes Of Failure ◽  
Composite Pressure Vessel ◽  
Mode Of Failure ◽  
Composite Pressure Vessels

The ASME Boiler and pressure vessel code Section VIII Division 2 and the European unfired pressure vessel code EN13445 Part 3 Design by Analysis parts dealing primarily with steel pressure vessels have been around for the last ten to fifteen years. The culmination of work on pressure vessel design by analysis address failure modes directly and are very efficient in order to guarantee that the designed and fabricated steel pressure vessels are fit for their purpose. The ASME Boiler and pressure vessel code Section X and the European codes BS EN13923 and BS EN13121 are some of the existing codes that cover design methods for composite pressure vessels. In these codes various failure criteria and damage mechanics models are possible but as such no comprehensive and robust design by analysis methods have been effectively established to encapsulate all composite pressure vessel failure modes. For instance the design of fibre-reinforced composite pressure vessels is still heavily reliant on experimental testing and prototype verification as opposed to the well-established design by analysis methods applicable to steel pressure vessels. Nonetheless a number of damage mechanics models ranging from mesoscale to microscale models have been established in other research work done on composite materials. This paper reviews the different composite pressure vessel design methods identified in the codes and standards and assesses damage mechanisms that can be used within a design by analysis context to design against possible modes of failure such as the limit load mode of failure, the progressive deformation mode of failure, the fatigue mode of failure and the buckling mode of failure. Damage mechanisms can also be used to develop criteria that allow a stress analyst deduce whether the material has failed, how it has failed and whether it has lost its capability to carry the load actions applied to it. The paper also highlights requirements for design methods based on the finite element method, and the necessary experimental validation required for different damage mechanisms leading to the different modes of failure.

Safety Assessment of Long Term Serviced Pressure Vessels: A Case Study of Typical Refining and Chemical Plants in China

2021 ◽  
Author(s):  
Zhiyuan Han ◽  
Guoshan Xie ◽  
Haiyi Jiang ◽  
Xiaowei Li
Keyword(s):  
Pressure Vessel ◽  
Safety Assessment ◽  
Failure Modes ◽  
Pressure Vessels ◽  
Time Dependent ◽  
Chemical Plants ◽  
Safety Specification ◽  
Detailed Assessment

Abstract The safety and risk of the long term serviced pressure vessels, especially which serviced more than 20 years, has become one of the most concerned issues in refining and chemical industry and government safety supervision in China. According to the Chinese pressure vessel safety specification TSG 21-2016 “Supervision Regulation on Safety Technology for Stationary Pressure Vessel”, if necessary, safety assessment should be performed for the pressure vessel which reaches the design service life or exceeds 20 years without a definite design life. However, the safety and risk conditions of most pressure vessels have little changes after long term serviced because their failure modes are time-independent. Thus the key problem is to identify the devices with the time-dependent failure modes and assess them based on the failure modes. This study provided a case study on 16 typical refining and chemical plants including 1870 pressure vessels serviced more than 20 years. The quantitative risk and damage mechanisms were calculated based on API 581, the time-dependent and time-independent failure modes were identified, and the typical pressure vessels were assessed based on API 579. Taking the high pressure hydrogenation plant as an example, this study gave the detailed assessment results and conclusions. The results and suggestions in this study are essential for the safety supervision and extending life of long term serviced pressure vessels in China.

Nonlinear Analysis in Pressure Vessel Design Codes: Recommendations for Codified Rules Improvements

2018 ◽  
Author(s):  
Claude Faidy
Keyword(s):  
Material Properties ◽  
Failure Modes ◽  
Plastic Instability ◽  
Pressure Vessels ◽  
Inelastic Analysis ◽  
Stress Classification ◽  
Piping Systems ◽  
Plastic Shakedown ◽  
Stress Criteria

During the past 30 years the main rules to design pressure vessels were based on elastic analyses. Many conservatisms associated to these different elastic approaches are discussed in this paper, like: stress criteria linearization for 3-D components, stress classification in nozzle areas, plastic shake down analysis, fatigue analysis, Ke evaluation, and pipe stress criteria for elastic follow-up due to thermal expansion or seismic loads... This paper will improve existing codified rules in nuclear and non-nuclear Codes that are proposed as alternatives to elastic evaluation for different failure modes and degradation mechanisms: plastic collapse, plastic instability, tri-axial local failure, rupture of cracked component, fatigue and Ke, plastic shakedown. These methods are based on limit loads, monotonic or cyclic elastic-plastic analyses. Concerned components are mainly vessels and piping systems. No existing Code is sufficiently detailed to be easily applied; the needs are stress analysis methods through finite elements, material properties including material constitutive equations and criteria associated to each methods and each failure modes. A first set of recommendation to perform these inelastic analysis will be presented to improve existing codes on an international harmonized way, associated to all material properties and criteria needed to apply these modern methods. An international draft Code Case is in preparation.

Brittle Fracture Assessments on Piping Systems: MSOT Curves

2019 ◽  
Author(s):  
Ishita Chakraborty ◽  
Kannan Subramanian ◽  
Jorge Penso
Keyword(s):  
Brittle Fracture ◽  
Case Studies ◽  
Pressure Vessel ◽  
Iterative Process ◽  
Pressure Vessels ◽  
Temperature Changes ◽  
End Conditions ◽  
Piping Systems ◽  
Plant Personnel ◽  
Safe Operating

Abstract Brittle fracture assessments (BFAs) of pressure vessels based on API 579-1/ASME FFS-1, Section 3 procedures are frequently easier and more straightforward to implement in comparison to the BFAs on piping systems. Specifically, the development of the MSOT curves. This is due to the complexities involved in the piping systems due to the branch piping interactions, end conditions of piping systems such as nozzle flexibilities at the pressure vessel connections, temperature changes in the length of piping especially when the piping is significantly long as seen in flare header piping systems. MSOT curves that are alternatively used for MAT curves provide a better picture to the plant personnel in understanding the safe operating envelope. Development of MSOT curves is an iterative process and therefore involves significant number of piping stress analyses during their development. In this paper, an approach to develop the MSOT curves is discussed with two case studies that are of relevance to olefin plants.

scholarly journals Influence of preliminary thermomechanical load on the integrity of the vessel of Ukrainian nuclear reactors in case of accidents of "large" and "small" leak

2021 ◽  
Author(s):  
Oleksii Ishchenko
Keyword(s):  
Brittle Fracture ◽  
Pressure Vessel ◽  
Fracture Resistance ◽  
Emergency Situation ◽  
Pressure Vessels ◽  
Reactor Pressure Vessel ◽  
Brittle Strength ◽  
Brittle Fracture Resistance ◽  
Small Leak ◽  
Reactor Pressure

In works of extending lifetime of WWER-type reactors, it is necessary to obtain the brittle fracture resistance (BF) of the reactor pressure vessel (RPV). Implementation calculations for brittle fracture resistance is regulated by the technical PNAE of Ukraine. The objective of these calculations is to prevent catastrophic brittle destruction of the reactor pressure vessel, pipelines and pressure vessels from the existence crack-like defects for all operating regimes, including emergency situations (ES). The paper considers the most dangerous postulated emergency situation in operation is "large" and "small" leak in the RPV NPP. Calculations with Warm Pre-Stressing effect (WPS) of the RPV for the most dangerous scenarios have been presented, and an assessment of the brittle strength of RPV NPP is taking into account with WPS. The results of studies with factor of brittle strength safety are also presented without taking into account the Warm Pre-Stressing, comparing with the existing method for accounting this type of load.

Investigation on the Effects of Carbon Macro-Segregation of Mechanical Properties Using a Large-Scale Forged Low Alloy Steel for a BWR Reactor Pressure Vessel

2020 ◽  
Author(s):  
Takahiro Hayashi ◽  
Takuya Ogawa ◽  
Rie Sumiya ◽  
Tetsushi Yamaoka ◽  
Shigeaki Tanaka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Content ◽  
Pressure Vessel ◽  
Material Properties ◽  
Large Scale ◽  
Structural Reliability ◽  
Pressure Vessels ◽  
Reactor Pressure Vessel ◽  
Steel Making ◽  
Reactor Pressure

Abstract Control of carbon macro-segregation in the steel-making process for large steel forgings is of great importance in order to achieve the material properties and structural reliability required for the pressure vessels of nuclear power plant components. It is well known that high carbon content due to carbon macro-segregation can affect the mechanical properties of steels, leading to decreases in ductility and fracture toughness. In this study, possible effects of carbon macro-segregation have been examined using a large-scale forged steel “bottom head dome” of a reactor pressure vessel (RPV) manufactured for a recent BWR. Material testing conducted included chemical analyses, tensile tests and Charpy impact tests. In the center part of the concave disk-shaped forged material, carbon content varied slightly in the material thickness direction within the range of carbon content requirement, as expected from the relationship between the solidification and the resultant segregation process in the cast ingot material and the forging process from the ingot to the dome material. The results of each mechanical test also showed full compliance with the properties required in the code regardless of the carbon content at each of the thickness locations examined. All the tests results demonstrated that with the steel-making technology and practice employed, carbon macro-segregation is well controlled to achieve the required material properties even in large-scale forged materials used in BWRs.

Design Criteria for Boilers and Pressure Vessels in the U.S.A.

1988 ◽  
Vol 110 (4) ◽  
pp. 430-443 ◽  
Author(s):  
Martin D. Bernstein
Keyword(s):  
Elevated Temperature ◽  
Pressure Vessel ◽  
Failure Modes ◽  
Pressure Vessels ◽  
Design Criteria ◽  
The Future ◽  
Recent Developments ◽  
Design Loads ◽  
Elevated Temperature Design

Preface. Code criteria defined. Evolution of ASME Boiler and Pressure Vessel Code. How the Code operates today. Design by rule. Evolution of design by analysis. Types of stress and their significance. Failure modes. Strength theories. Design loads. New or unusual designs. Code Cases. Interpretations. Stress limits for design by rule and design by analysis. Elevated temperature design. Recent developments. A glimpse at the future. References.

The Plastic Work Curvature Criterion in Evaluating Gross Plastic Deformation for Pressure Vessels with Conical Heads

2011 ◽  
Vol 50-51 ◽  
pp. 93-99 ◽  
Author(s):  
Mohammad Zehsaz ◽  
Farid Vakili Tahami ◽  
Yasser Ashraf Gandomi
Keyword(s):  
Plastic Deformation ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
International Standards ◽  
Plastic Work ◽  
Elastic Response ◽  
Plastic Collapse ◽  
Conical Shells ◽  
Compressive Stresses ◽  
New Criterion

Conical shells are often joined to cylindrical shells and under internal pressure, the intersection between the large end of a cone and a cylinder is subjected to a large circumferential compressive stresses which can lead to its failure by whether axi-symmetric gross plastic deformation involving excessive inward deformations or non-symmetric buckling which accompanies by circumferential waves around the intersection. In Pressure Vessel Design by Analysis, the designer is required to address both these behavior modes when specifying the allowable static load. In this paper, plastic collapse or gross plastic deformation load is evaluated for a typical pressure vessel with conical head using plastic work curvature criterion and the results are compared with other criteria suggested by international standards such as ASME. The plastic work curvature criterion is based on the plastic work dissipated in the structure as loading progresses and may be used for structures subject to a single load or a combination of multiple loads. The results of analyzing using this new criterion show that the plastic collapse load given by the plastic work curvature criterion is robust and consistent and is in the close agreement with the results from international codes. The most significant aspect of the proposed method in which plastic work curvature criterion has been used is that the plastic collapse loads are determined purely by the inelastic response of the structure and therefore they are not influenced by the initial elastic response: a problem with some other established plastic criteria. The results also show that the design load is mostly limited by the formation of an axi-symmetric gross plastic deformation in the intersection of the vessel prior to the formation of non-symmetric buckling modes

Prestressing a Two-Layer Pressure Vessel by Plastic Deformation

1965 ◽  
Vol 87 (1) ◽  
pp. 97-103
Author(s):  
R. W. Schneider
Keyword(s):  
Plastic Deformation ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
Work Hardening ◽  
Design Method ◽  
Strain Curve ◽  
Pressure Vessels ◽  
Stress Strain Curve ◽  
Initial Clearance ◽  
Actual Stress

A method of prestressing two-layer pressure vessels by controlled yielding of the inner layer by internal pressure is described. The required prestressing pressure depends upon the dimensions of the vessel, the initial clearance between layers, and the properties of the material of construction. The design method takes into account the actual stress-strain curve of the material and satisfies the rules of plastic flow with work-hardening. Two-layer, cylindrical vessels are discussed in detail.

Brittle Fracture Prevention Model for Pressure Based on Master Curve Approach

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
QingFeng Cui ◽  
Hu Hui ◽  
PeiNing Li ◽  
Feng Wang
Keyword(s):  
Fracture Toughness ◽  
Brittle Fracture ◽  
Impact Toughness ◽  
Pressure Vessel ◽  
Master Curve ◽  
Fracture Prevention ◽  
Pressure Vessels ◽  
New Model ◽  
Prevention Model ◽  
The Impact

The brittle fracture prevention model is of great importance to the safety of pressure vessels. Compared to the semi-empirical approach adopted in various pressure vessel standards, a model based on Master Curve technique is developed in this paper. Referring to ASME nuclear code, the safety features including the lower bound fracture toughness and a margin factor equal to 2 for the stress intensity factor produced by primary stress are adopted in the new model. The technical background of the brittle fracture model in ASME VIII-2 has been analyzed and discussed, and then its inappropriate items have been modified in the new model. Minimum design temperature curves, impact toughness requirements, and temperature adjustment for low stress condition are established on the basis of new model. The comparison with the relevant curves in ASME VIII-2 is also made. The applicability of the new model is verified by the measured fracture toughness and impact toughness data of several kinds of pressure vessel steels. The results suggest that the minimum design temperature and the impact test requirements derived by the new model are compatible with each other. More testing data of different steels to check this model is necessary for further engineering application.

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