scholarly journals Example of stress evaluation for a pipe subjected to impeded thermal expansion according to ASME code

2021 ◽  
Vol 3 (2) ◽  
pp. 120-131
Author(s):  
Costin Ilincă ◽  
Maria Tănase ◽  
Marius Gabriel Petrescu
Keyword(s):  
Thermal Expansion ◽  
Stress Evaluation ◽  
Asme Code

Ratchet Boundary for Superimposed Biaxial Membrane Stress States

2018 ◽  
Author(s):  
Wolf Reinhardt
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
Analytical Solution ◽  
Pressure Vessels ◽  
Stress Fields ◽  
Design Codes ◽  
Bending Stress ◽  
Membrane Stress ◽  
Asme Code ◽  
Stress States

Thermal membrane and bending stress fields exist where the thermal expansion of pressure vessel components is constrained. When such stress fields interact with pressure stresses in a shell, ratcheting can occur below the ratchet boundary indicated by the Bree diagram that is implemented in the design Codes. The interaction of primary and thermal membrane stress fields with arbitrary biaxiality is not implemented presently in the thermal stress ratchet rules of the ASME Code, and is examined in this paper. An analytical solution for the ratchet boundary is derived based on a non-cyclic method that uses a generalized static shakedown theorem. The solutions for specific applications in pressure vessels are discussed, and a comparison with the interaction diagrams for specific cases that can be found in the literature is performed.

Piping Local Stresses for Solid Versus Hollow Attachments

2005 ◽  
Author(s):  
C. Basavaraju ◽  
R. C. Fox
Keyword(s):  
Finite Element ◽  
Wall Thickness ◽  
Cylindrical Shells ◽  
Local Stress ◽  
Support Design ◽  
Element Analysis ◽  
Stress Evaluation ◽  
Local Stresses ◽  
Asme Code ◽  
The Impact

The simple and most commonly used WRC-107 (Welding Research Bulletin #107) Bijlaard methodology for local stress evaluation addresses cylindrical shells and pipes with solid circular, rectangular, and square attachments only. Hollow circular, square, or rectangular tubular shaped attachments on cylindrical shells, though commonly used, are not addressed in WRC-107. ASME Code Case N-392 addresses hollow circular attachments on pipes but is known to be conservative. This paper studies commonly encountered sizes of hollow circular, hollow square, and hollow rectangular attachments of various wall thicknesses on piping utilizing rigorous finite element analysis (FEA) method to obtain the local stresses at the pipe/attachment interface due to mechanical loads. A total of fifty (50) finite element models were analyzed to study the most frequently used configurations. The impact of attachment wall thickness including solid attachment will be addressed. A comparison of finite element results with WRC-107 solid attachment results, when applicable, will be made. Recommendations and guidelines are provided based on the results of the FEA study. The objective is to reduce conservatism, and hence the associated cost in piping and pipe support design by optimizing the round attachment’s wall thickness.

A New Shape of Expansion Loop to Compensate Thermal Expansion of Piping Systems

2009 ◽  
Author(s):  
Aurel M. Alessandrescu
Keyword(s):  
Thermal Expansion ◽  
Heavy Water ◽  
Operating Conditions ◽  
Piping System ◽  
Analysis Program ◽  
Alternative Compensation ◽  
Pipe Expansion ◽  
Water Plant ◽  
Piping Systems ◽  
Asme Code

To provide the piping system self-compensation under the conditions in which lenticular thermal pipe expansion devices cannot be used due to the crack induced corrosion (e.g.in the Heavy Water Plant) is accomplished by special devices (e.g. U,L,Z type). Under such circumstances a novative alternative compensation solution was implemented, namely, the employment of ROTATING Z type or AA (VΛ). Such a type of compensation consists in 2× 90° pipe bends and 2× 45° pipe bends. Calculations of 15 alternative compensation solutions with more over 120 variants of materials, nominal diameter, operating conditions (Po, To) were made by running CaePipe 5.15 analysis program for 3 cases: sustained, thermal expansion and operating. The stress and distorsion conditions of the new shape satisfied the requirements in ASME Code B31.3 evidencing that this shape provides the most favorable results.

An Overview of ASME Section III Class 2 and 3 Valve Design and Service Loading Rules

2020 ◽  
Author(s):  
Ronald Farrell ◽  
Jason Lambin
Keyword(s):  
Pressure Vessel ◽  
Working Group ◽  
Historical Perspective ◽  
Local Stress ◽  
Code Design ◽  
Bending Stress ◽  
Valve Design ◽  
Design Rules ◽  
Stress Evaluation ◽  
Asme Code

Abstract In addition to providing an overview of the ASME Boiler and Pressure Vessel Code design rules applicable to Class 2 and 3 valves, where Class is defined in Section III of the ASME Code, Sub-Article NCA-2130, this paper offers some insight as to why the rules are as they are. The motivation comes from a request by the ASME Codes and Standards Committee, Components Subgroup, for the Valve Working Group to prepare this overview. The request came after discussing a question from a participant regarding how the “(Primary Membrane or Local) plus Bending” stress category should be addressed for a valve. The paper goes beyond a basic overview of Code rules as it includes a discussion of the underlying valve standard ASME B16.34, looks at the valve rules in relation with the rest of the Code, and contributes some historical perspective. From a perusal of the Code both in general and during preparation of this paper, it is concluded that the valve Code rules could benefit from a few clarifications; thus, changes are proposed, and the Working Group is encouraged to consider them. In answer to the underlying question regarding the primary local stress category, it is shown that the need for a local stress evaluation would be rare for a valve.

A Practical Method Based on Stress Evaluation (σd Criterion) to Predict Initiation of Crack Under Creep and Creep-Fatigue Conditions

1995 ◽  
Vol 117 (4) ◽  
pp. 335-340 ◽  
Author(s):  
D. Moulin ◽  
B. Drubay ◽  
D. Acker ◽  
L. Laiarinandrasana
Keyword(s):  
High Temperature ◽  
Crack Front ◽  
Practical Method ◽  
Small Distance ◽  
Strain History ◽  
Stress Evaluation ◽  
Simplified Method ◽  
Creep Fatigue ◽  
Asme Code ◽  
Nuclear Structures

The behavior of defects like cracks in nuclear components operating at high temperature, where creep is significant, must be under control. There exists the need to have a practical method of analysis, which can be used by engineers, to calculate the time of initiation for defects existing at the start of life of nuclear components. This study presents the background, the development, the application, and results concerning validation work made for a simplified method named σd of prediction of initiation for nuclear structures made of 316L austenitic steel and operating at temperature where creep is significant. This method relies on the evaluation of real stress-strain history on a small distance d (d = 0.05 mm) close to the crack front and material characteristics (limiting stresses) that are available in nuclear codes like ASME Code cases or RCC-MR.

The Effect of Steady State Thermal Loading on the Deflections of a Flanged Joint With a Cover Plate

2002 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Akli Nechache ◽  
Warren Brown
Keyword(s):  
Thermal Expansion ◽  
Steady State ◽  
Temperature Profile ◽  
Thermal Effects ◽  
Thermal Loading ◽  
Cover Plate ◽  
Asme Code ◽  
Effects Of Temperature ◽  
Bolted Flange

It is well recognized that bolted flange joints operating at high temperature are often very difficult to seal. The existing flange design methods including that of the ASME code do not address thermal effects other than the variation of flange and bolt material mechanical properties with temperature. It is possible to include the effects of temperature loading in the flexibility analysis of the joint. However, the temperature profile to be known to determine the radial and axial thermal expansion displacements of the joint elements to be used in the analysis. This paper outlines the theoretical analysis used for the determination of the steady state operating temperature profile, the thermal expansion displacements of the joint components and the bolt load changes for the case of a flange joint with a blind cover. The results from the proposed analytical model are verified by comparison to finite element results of three different sizes of bolted joints.

Numerical Estimate of Elastic Follow-Up in Piping: Inelastic Evaluation

1986 ◽  
Vol 108 (4) ◽  
pp. 453-460 ◽  
Author(s):  
A. K. Dhalla
Keyword(s):  
Thermal Expansion ◽  
Numerical Estimate ◽  
Large Diameter ◽  
Piping System ◽  
Fast Breeder Reactor ◽  
System Configuration ◽  
Primary Stress ◽  
Asme Code ◽  
Inelastic Strains

Large-diameter thin-walled piping such as that used in the Liquid Metal Fast Breeder Reactor (LMFBR) plant is characterized by relatively stiff straight pipes welded to flexible elbows. According to Robinson [1], such a piping system configuration may experience elastic follow-up during elevated temperature operation. Therefore, ASME Code Case N-47 requires that the secondary thermal expansion stress “. . . with large amounts of elastic follow-up . . .” be considered a load-controlled primary stress. A procedure to calculate the extent of potential elastic follow-up and thereby classify the thermal expansion stress as either primary or secondary is presented here. The elastic follow-up effect is investigated in detail by evaluating spatial and temporal redistribution of loads and inelastic strains computed for a typical LMFBR piping system.

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

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