The Effects of the Distance Between Two Defects on the Load-Carrying Capacity of a Pressure Vessel

1999 ◽  
Vol 122 (2) ◽  
pp. 198-203
Author(s):  
H. F. Chen ◽  
D. W. Shu
Keyword(s):  
Numerical Method ◽  
Curve Fitting ◽  
Upper Bound ◽  
Carrying Capacity ◽  
Pressure Vessel ◽  
Empirical Formula ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Single Defect ◽  
Load Carrying

A simplified numerical method for both lower and upper-bound limit analyses of 3-D structure has been developed in our previous work. The load-carrying capacities of 3-D pipelines with either one or two part-through defects of various geometrical configurations were calculated by the proposed method. In the present paper, the effects of the distance between two defects on the load-carrying capacity of pressure vessels are evaluated and discussed in details. Using curve-fitting schemes, an empirical formula for obtaining the load-carrying capacity of pressure vessels with double defects from that of pressure vessels with a single defect are proposed. Some engineering suggestions are presented simultaneously. All the numerical results confirm the applicability of the simplified numerical method. [S0094-9930(00)00102-5]

Investigation of Burst Pressure in T-Joints With Wall-Thinning by Using FEA

2017 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Element Analysis ◽  
T Joints ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in numerous industrial plants, and damaged equipment in the plants is often detected by visual inspection or non-destructive inspection techniques. The most common type of damage is wall thinning due to corrosion under insulation (CUI) or flow-accelerated corrosion (FAC), or both. Any damaged equipment must be repaired or replaced as necessary as soon as possible after damage has been detected. Moreover, optimization of the time required to replace damaged equipment by evaluating the load carrying capacity of boilers and pressure vessels with wall thinning is expected by engineers in the chemical industrial field. In the present study, finite element analysis (FEA) is used to evaluate the load carrying capacity in T-joints with wall thinning. Burst pressure is a measure of the load carrying capacity in T-joints with wall thinning. The T-joints subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The burst pressure is investigated by comparing the results of burst testing with the results of FEA. Moreover, the maximum allowable working pressure (MAWP) of T-joints with wall thinning is calculated, and the safety margin for the burst pressure is investigated. The burst pressure in T-joints with wall thinning can be estimated the safety side using FEA regardless of whether the model is a shell model or a solid model. The MAWP is 2.6 MPa and has a safety margin 7.5 for burst pressure. Moreover, the MAWP is assessed the as a safety side, although the evaluation is too conservative for the burst pressure.

Load‐carrying capacity of spherical pressure vessels weakened by butt joints

2001 ◽  
Vol 15 (2) ◽  
pp. 153-157
Author(s):  
V V Erofeev ◽  
M V Shakhmatov ◽  
M V Erofeev ◽  
V V Kovalenko
Keyword(s):  
Carrying Capacity ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Butt Joints ◽  
Load Carrying ◽  
Spherical Pressure

Analysis of the load-carrying capacity of pressure vessels in the presence of through cracks

1989 ◽  
Vol 21 (11) ◽  
pp. 1454-1459
Author(s):  
N. A. Makhutov ◽  
M. I. Burak ◽  
V. B. Kaidalov
Keyword(s):  
Carrying Capacity ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Load Carrying

Limit Load Analysis of Cylindrical Vessels Under Internal Pressure and Axial Strain

2011 ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Internal Pressure ◽  
Carrying Capacity ◽  
Pressure Vessel ◽  
Axial Strain ◽  
Limit State ◽  
Limit Load ◽  
Operating Pressure ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Load Analysis

Strain-based design is a newer technology used in safety design and integrity management of oil and gas pipelines. In a traditional stress-based design, the axial stress is relatively small compared to the hoop stress generated by internal pressure in a line pipe, and the limit state in the pipeline is usually load-controlled. In a strain-based design, however, axial strain can be large and the load-carrying capacity of pipelines could be reduced significantly below an allowed operating pressure, where the limit state is controlled by an axial strain. In this case, the limit load analysis is of great importance. The present paper confirms that the stress, strain and load-carrying capacity of a thin-walled cylindrical pressure vessel with an axial force are equivalent those of a long pressurized pipeline with an axial tensile strain. Elastic stresses and strains in a pressure vessel are then investigated, and the limit stress, limit strain and limit pressure are obtained in terms of the classical Tresca criterion, von Mises criteria, and a newly proposed average shear stress yield criterion. The results of limit load solutions are analyzed and validated using typical experimental data at plastic yield.

Optimal Shapes for Axisymmetric Pressure Vessels: A Brief Overview

2000 ◽  
Vol 122 (4) ◽  
pp. 443-449 ◽  
Author(s):  
Lei Zhu ◽  
J. T. Boyle
Keyword(s):  
Pressure Vessel ◽  
Limit Load ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Limit Pressure ◽  
Optimal Shapes ◽  
Load Carrying ◽  
Analysis System ◽  
Elastic Compensation Method

This paper describes how optimal shapes for axisymmetric pressure vessels can be established based on maximizing limit pressure. This type of problem has been rarely examined in the literature due to the difficulty of evaluating limit loads. However, the “elastic compensation method” is used to approximate the limit load using elastic analysis alone, which opens the possibility of studying shape optimization based on limit pressure. The basic procedure, using a commercial finite element analysis system, is described and three example problems are examined. The aim is to investigate how much of an increase in load-carrying capacity could potentially be achieved if nonstandard pressure vessel shapes could be employed in practice. Of course, this may not be possible, but the results described here do contribute to a better understanding of the role shape plays in providing strength to a simple pressure vessel. [S0094-9930(00)00304-8]

Investigation of Burst Pressure in Pipes With Square Wall Thinning by Using FEA and API579 FFS-1

2013 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Fe Analysis ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Accelerated Corrosion ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in chemical industrial plants and equipment is inspected periodically for damage. The most common type of damage is wall thinning due to Flow-Accelerated Corrosion (FAC) or corrosion under insulation (CUI). Any damage must be repaired or replaced as necessary. On the other hand, optimization of the time required in order to replace damaged equipment by evaluating the load carrying capacity of pipes with wall thinning is expected in chemical industrial field. In the present study, FE analysis is used in order to evaluate the load carrying capacity in pipes with wall thinning. Burst pressure is a measure of the load carrying capacity in pipes with wall thinning. The pipes subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The examined wall thinning is rectangular, and the eroded depth is half the pipe wall thickness. The burst pressure is investigated by comparing the results of burst testing with the results of FE analysis. Moreover, the reduced maximum allowable working pressure (MAWPr), which is calculated by fitness-for-service (FFS) assessment, and the safety margin for burst pressure are investigated. The burst pressure calculated by FEA agrees well with the test results, except for square wall thinning for circumferential angles of less than 15°. Also, the safety margin of MAWPr based on FFS-1 Part 4 is over 4.0 times for burst pressure.

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