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

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.

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

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.

Carrying Capacity of Strain-Hardening Austenitic Stainless Steel Pressure Vessels Under Hydrostatic Pressure

2011 ◽  
Author(s):  
Yang-chun Deng ◽  
Gang Chen
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Hydrostatic Pressure ◽  
Austenitic Stainless Steel ◽  
Strain Hardening ◽  
Carrying Capacity ◽  
Plastic Instability ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Load Carrying

To reduce the waste of austenitic stainless steels due to their low yield strengths, the strain hardening technology is used to significantly improve their yield strength, in order to increase the elastic load carrying capacity of austenitic stainless steel pressure vessels. The basic principle of strain-hardening for austenitic stainless steel pressure vessels and two common models of strain hardening, including Avesta Model for ambient temperature and Ardeform Model for cryogenic temperature, were briefly introduced. However, it was fully established by experiments, the lack of a necessary theoretical foundation and the safety concern affect its widespread use. In this study, we investigated the load carrying capacity of strain-hardening austenitic stainless steel pressure vessels under hydrostatic pressure, based on the elastic-plastic theory. To understand the effects of strain hardening on material behavior, the plastic instability loads of a round tensile bar specimen were also derived under two different loading paths and validated by experiments. The results of theoretical, experimental and finite element analyses illustrated, considering the effect of material strain hardening and structural deformation, at ambient temperature, the static load carrying capacity of pressure vessels does not relate to the loading paths. To calculate the plastic instability pressures, a method was proposed so that the original dimension and original material parameters prior to strain hardening can be used either by the theoretical formula or finite element analysis. The safety margin of austenitic stainless steel pressure vessels under various strain hardening degrees was quantitatively analyzed by experiments and finite element method. A 5% strain as the restrictive condition of strain hardening design for austenitic stainless steel pressure vessels was suggested.

Enhancement of Load-Carrying Capacity of Undermatching Butt Joints by Weld Shape Design

2011 ◽  
Vol 189-193 ◽  
pp. 3279-3283 ◽  
Author(s):  
Zhi Li Zhao ◽  
Tao Wang ◽  
Hong Yuan Fang ◽  
Jian Guo Yang
Keyword(s):  
Carrying Capacity ◽  
Welded Joints ◽  
Weld Zone ◽  
Geometric Parameters ◽  
Shape Design ◽  
Load Carrying Capacity ◽  
Butt Joints ◽  
Critical Crack ◽  
Weld Shape ◽  
Load Carrying

A new attempt is proposed to improve the load-carrying capacity of high strength steel undermatching butt welded joints by shape design. Based on the principle that reasonable geometric parameters designs of welded joints can regulate the distribution of stress and strain, reduce the stress concentration factors in low strength weld zone, the geometric parameters of undermatching butt joints, such as weld toe radius, height of excess weld metal and width of the cover passes are designed. A series of tests were completed to investigate the effect of weld shape design on the mechanical properties and security of undermatching butt joints. The results showed that the critical crack sizes of the 0.6~1.0 undermatching joints is greater than or equal to the one of base metal, the joints strengths approach to the tensile strength of base mental, and the fatigue strength is far higher than that of the as-welded equalmatching butt joints.

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]

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