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

1988 ◽  
Vol 110 (4) ◽  
pp. 430-443 ◽  
Author(s):  
Martin D. Bernstein

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.

2021 ◽  
Author(s):  
Zhiyuan Han ◽  
Guoshan Xie ◽  
Haiyi Jiang ◽  
Xiaowei Li

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.


Author(s):  
Chithranjan Nadarajah ◽  
Benjamin F. Hantz ◽  
Sujay Krishnamurthy

ASME Section VIII, Division II, Boiler and Pressure Vessel Code does not have any design by analysis procedures for designing pressure vessel components in the creep regime. This publication presents a methodology for evaluating and categorizing elastic stresses calculated from finite element stress analysis when designing in the creep regime. The proposed methodology is compared with multi axial creep results for various pressure vessel components and found to be in reasonable agreement.


Author(s):  
William Koves ◽  
Elmar Upitis ◽  
Richard Cullotta ◽  
Omar Latif

Every engineering project involving the design of pressure equipment, including pressure vessels, heat exchangers and the interconnecting piping requires that the interface loads between the equipment and piping be established for the pressure vessel nozzle design and the limitations on piping end reactions. The vessel or exchanger designer needs to know the external applied loads on nozzles and the piping designer needs to know the limiting end reactions on any connected equipment. However, the final loads are not known until the piping design is completed. This requires a very good estimate of the piping end loads prior to completing the vessel or piping design. The challenge is to develop a method of determining the optimum set of design loads prior to design. If the design loads are too low, the piping design may become too costly or impractical. If the design loads are too high the vessel nozzle designs will require unnecessary reinforcement and increased cost. The problem of the stresses at a nozzle to vessel intersection due to internal pressure and external forces and moments is one of the most complex problems in pressure vessel design. The problem has been studied extensively; however each study has its own limitations. Numerous analytical and numerical simulations have been performed providing guidance with associated limitations. The objective is to establish allowable nozzle load tables for the piping designer and the vessel designer. The loads and load combinations must be based on a technically accepted methodology and applicable to all nozzle sizes, pressure classes, schedules and vessel diameters and thicknesses and reinforcement designs within the scope of the tables. The internal design pressure must also be included along with the 3 forces and 3 moments that may be acting on the nozzle and the nozzle load tables must be adaptable to all materials of construction. The Tables must also be applicable for vessel heads. This paper presents the issues, including the limitations of some of the existing industry approaches, presents an approach to the problem, utilizing systematic Finite Element Analysis (FEA) methods and presents the results in the form of tables of allowable nozzle loads.


Author(s):  
Ch. Botsis ◽  
G. Anagnostides ◽  
N. Kokavesis

Nozzle loads impose an important constraint in the design of pressure containing equipment. Pressure vessels are connected to external piping by a nozzle welded to the vessel wall and a flange connection. The nozzle loads are due to the piping expansion or contraction caused by the difference between the installation and operating temperatures. Pressure vessel designers need to know, early in the design process, the piping loads that a nozzle may be subjected to. It is important that such loads do not overstress the vessel-nozzle intersection. However the actual piping loads many times are only determined long after the pressure vessel materials are ordered and even procured. The intention of this paper is to provide an empirical but also realistic load set as a function of nozzle external radius, r, vessel external radius, R, vessel thickness, t, and allowable stress, S. The basis of this work is practical experience and also existing theoretical work. This will be a valuable tool in the hands of the pressure vessel mechanical designer. It will allow him to prescribe an early-heuristic estimate of the allowable nozzle loads that will cover external piping loads. These “anticipated” or design loads will allow a pressure vessel mechanical designer to reinforce his design early into the manufacturing of a pressure vessel. Finally, piping engineers will know the terminal allowable loads and thus determine the best piping routing and support arrangements if space constraints allow it.


1964 ◽  
Vol 86 (4) ◽  
pp. 403-409 ◽  
Author(s):  
B. F. Langer ◽  
W. L. Harding

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.


2021 ◽  
Author(s):  
Bart Kemper ◽  
Guy Richards ◽  
Taylor Nappi ◽  
Veda Thipparthi ◽  
Ana Escobar

Abstract Section VIII of the Boiler and Pressure Vessel Code is introducing the use of acrylics as a pressure vessel material. The design method is specified in ASME PVHO-1, Safety Standard for Pressure Vessels for Human Occupancy. The current method relies upon an empirical method developed in the 1960–70’s. It does not use “allowable stress” or other mechanical properties traditionally used to calculate design dimensions, but instead uses a fixed range of dimensions for specific shapes and determines the wall thickness using a curve. Understanding the PVHO-1 design assumptions and typical failure modes is important for a non-PVHO pressure vessel designer using acrylics. An ASME Codes & Standards task group is developing a “design by analysis” method (DBA) for acrylics and other glassy polymers for pressure vessel components. The proposed DBA methodology uses Verification and Validation (V&V) techniques and Finite Element Method (FEM) as the design method framework in order to advance the use of glassy polymers as pressure vessel materials.


Author(s):  
Chen Xuedong ◽  
Fan Zhichao ◽  
Dong Jie ◽  
Ai Zhibin ◽  
Hu Mingdong

Abstract In recent years, a large number of pressure vessels for the petrochemical plants built in China in the 20th century have been in service for more than 20 years. The Chinese pressure vessel safety specification TSG 21-2016 “Supervision Regulation on Safety Technology for Stationary Pressure Vessel” stipulates that if the pressure vessels without definite design lives have been in service for more than 20 years, they shall be considered to have reached the design service lives. For these pressure vessels, if they are all blindly scrapped, it will cause huge economic losses. However, if they continue to be used blindly, it may bring great safety risks. In this paper, the failure mode, mechanism and damage evolution law are analyzed through a number of failure accident investigations and experimental studies, for typical pressure vessels such as large LPG spherical tanks, pressure swing adsorbers and coke drums. The classification method of pressure vessel for the time-independent and time-dependent failure modes has been proposed. As for the pressure vessels with time-independent failure modes, the principle to determine target life, and the strategy of inspection and maintenance have been proposed. While for the time-dependent failure modes, the safety evaluation and remaining life prediction methods for the pressure vessels with and without defects have been provided. Finally, the advices on amendment to the relevant regulations on pressure vessels have been proposed. The research findings could provide guidance for rationally determining the safety grades and scientifically extending the service lives of pressure vessels.


Author(s):  
Martin Muscat ◽  
Duncan Camilleri ◽  
Brian Ellul

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.


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