Critical states of longitudinal seam pipesof large diameter under axial compression and internal pressure

2021 ◽  
Vol 6 (2) ◽  
pp. 208-216
Author(s):  
V. L. Dilman ◽  
T. V. Karpeta
Keyword(s):  
Internal Pressure ◽  
Axial Compression ◽  
Large Diameter ◽  
Critical States ◽  
Longitudinal Seam

Application of Plastic Region Bolt Tightening to Flange Joint Assembly: Behavior of Large Diameter Flange

2009 ◽  
Author(s):  
Shinobu Kaneda ◽  
Hirokazu Tsuji
Keyword(s):  
Internal Pressure ◽  
Large Diameter ◽  
Plastic Region ◽  
Load Factor ◽  
Past Study ◽  
Flange Joint ◽  
The Past ◽  
Sealing Performance ◽  
Assembly Behavior ◽  
Bolted Flange

In the past study the plastic region tightening has been applied to the bolted flange joint with smaller nominal diameter and its advantages have been demonstrated, however, behavior of the bolted flange joint with larger diameter is not investigated. Flange rotation of the bolted flange joint with large diameter increases when the internal pressure is applied. Gasket stress is not uniform and it may cause leak accident. So, it is necessary to investigate the behavior of the larger diameter flange. The present paper describes the behavior of bolted flange joint with large diameter under plastic region tightening. Firstly, API 20-inch flange joint tightened to the plastic region by bolt with a smaller diameter and superiority in the uniformity of the axial bolt force is demonstrated. And then the internal pressure is applied to the bolted flange joint and the behavior of the additional axial bolt force is demonstrated. The axial bolt force decreases with increasing the internal pressure, and the load factor is negative due to increasing of the flange rotation. However, the load factor of the bolted flange joint tightened to the plastic region by using the bolt with the smaller diameter approached zero. Using the bolts with smaller diameter is advantageous to the flange joint with the larger diamter, whose load factor is negative, to prevent the leakage. Additionally, the leak rate from the bolted flange joint is measured and the sufficient sealing performance is obtained.

Effect of Expansion Ratio and Wall Thickness on Large-Diameter Solid Expandable Tubular after Expansion

2021 ◽  
Author(s):  
Changshuai Shi ◽  
Kailin Chen ◽  
Xiaohua Zhu ◽  
Feilong Cheng ◽  
Yuekui Qi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Internal Pressure ◽  
Wall Thickness ◽  
Performance Test ◽  
Large Diameter ◽  
Expansion Ratio ◽  
Fe Model ◽  
Laboratory Test Results ◽  
Low Efficiency ◽  
Pressure Resistance

Abstract The large-diameter solid expandable tubular with a smaller wall thickness faces the risk of internal pressure burst and external squeeze collapse in repairing damaged casing well. The internal pressure and external squeezing resistance calculation of the tubes using the analytical method require many expansion experiments and post-expansion tensile experiments, resulting in high costs and low efficiency. This paper gives a set of laboratory expansion and post-expansion performance test, which is based on the laboratory experiment and mechanical properties of material expansion. Two materials are studied: 316L and 20G. Then it analyses the error and causes of the error in the traditional analytical algorithm. Besides, it establishes an accurate finite element (FE) model to study the quantitative influence of expansion ratio and wall thickness on the burst strengths and collapse strengths of the tube. The results show that the toughness and hardening ratio of 316L is better than 20G at the same expansion ratio. The numerical simulation results of the model can effectively simulate the expansion process and the mechanical properties of SET in good agreement with the laboratory test results. The expansion ratio and wall thickness affect the mechanical properties after expansion. Thus the quantitative laws of the expansion driving force, internal pressure resistance, and external squeezing resistance under different variables are summarized. To ensure the integrity of the reinforced wellbore, the expansion ratio should not exceed 12.7%. In the current study lays a theoretical basis and technical support for optimizing SET and preventing downhole accidents.

Buckling Strength of Pressurized Cylindrical Shells under Axial Compression

2014 ◽  
Vol 638-640 ◽  
pp. 1750-1753
Author(s):  
Yu Chao Zheng ◽  
Yang Yan ◽  
Pei Jun Wang
Keyword(s):  
Numerical Simulation ◽  
Internal Pressure ◽  
Axial Compression ◽  
Parametric Study ◽  
Shell Thickness ◽  
Steel Shell ◽  
Plastic Buckling ◽  
Buckling Strength ◽  
Elastic Plastic ◽  
Steel Strength

A systematic parametric study was carried out to investigate the elastic and elastic-plastic buckling behaviors of imperfect steel shell subject to axial compression and internal pressure. Studied parameters include the magnitude of internal pressure, steel strength, and ratio of cylinder radius to shell thickness. Design equations were proposed for calculating the elastic and elastic-plastic buckling strength of imperfect steel shells under combination of axial compression and internal pressure. The buckling strength predicated by proposed equations agrees well with that from the numerical simulation.

Stress and flexibility factors for multi-mitred pipe bends subjected to internal pressure combined with external loadings

1972 ◽  
Vol 7 (2) ◽  
pp. 97-108 ◽  
Author(s):  
M P Bond ◽  
R Kitching
Keyword(s):  
Internal Pressure ◽  
Large Diameter ◽  
Pipe Bend ◽  
Bending Tests ◽  
Bending Load ◽  
Out Of Plane ◽  
Thin Walled ◽  
Plane Bending ◽  
Internal Pressures ◽  
Stress Patterns

The stress analysis of a multi-mitred pipe bend when subjected to an internal pressure and a simultaneous in-plane or out-of-plane bending load has been developed. Stress patterns and flexibility factors calculated by this analysis are compared with experimental results from a large-diameter, thin-walled, three-weld, 90° multi-mitred bend which was subjected to in-plane bending tests at various internal pressures.

Practical Design of Aluminium Silos According to EC9-1-5

2016 ◽  
Vol 710 ◽  
pp. 97-102 ◽  
Author(s):  
Peter Knoedel ◽  
Thomas Ummenhofer
Keyword(s):  
Internal Pressure ◽  
Aluminium Alloy ◽  
Axial Compression ◽  
Wall Thickness ◽  
Imperfection Sensitivity ◽  
Building Regulations ◽  
Federal States ◽  
Buckling Resistance ◽  
Practical Design ◽  
Made In

Within the code-family of the Eurocodes, provisions for aluminium shells are given in EN 1999-1-5 (EC9) [1]. EC9-1-5 is listed in the Bavarian List of Technical Building Regulations. Thus, in Bavaria as well as in other Federal States of Germany it is mandatory to use EC9-1-5 for the verification of silos. A typical aluminium silo for industrial products might have a diameter of 3 m, a bin height of 10 m and wall thicknesses of 4 mm / 5 mm. The aluminium alloy EN AW-5754 [Al Mg3] O/H111 (EN 485-2 [2]) would be typical as well. Relevant for determining the required wall thickness is the buckling resistance under axial compression in the skirt and axial compression with coexisting internal pressure in the silo bin. When some obvious shortcomings in the formulae for coexisting internal pressure were investigated, it was found that there is a big discrepancy between scientific research, which has been done on the imperfection sensitivity of aluminium shells and the design equations in EC9-1-5. In the present paper an effort was made, in order to tackle these discrepancies and make clear, in which points the code needs amendment.

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