scholarly journals Finite Element Analysis of Skirt to Shell Junction in a Pressure Vessel

2017 ◽  
Vol 10 (25) ◽  
pp. 1-10
Author(s):  
Deepali Mathur ◽  
Mandar Sapre ◽  
Chintan Hingoo ◽  
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2020 ◽  
Vol 117 ◽  
pp. 104791
Author(s):  
Nitikorn Noraphaiphipaksa ◽  
Piyamon Poapongsakorn ◽  
Anat Hasap ◽  
Chaosuan Kanchanomai

Author(s):  
Phillip E. Prueter ◽  
Brian Macejko

Post weld heat treatment (PWHT) is an effective way to minimize weld residual stresses in pressure vessels and piping equipment. PWHT is required for carbon steels above a Code-defined thickness threshold and other low-alloy steels to mitigate the propensity for crack initiation and ultimately, brittle fracture. Additionally, PWHT is often employed to mitigate stress corrosion cracking due to environmental conditions. Performing local PWHT following component repairs or alterations is often more practical and cost effective than heat treating an entire vessel or a large portion of the pressure boundary. In particular, spot or bulls eye configurations are often employed in industry to perform PWHT following local weld repairs to regions of the pressure boundary. Both the ASME Boiler and Pressure Vessel (B&PV) Code and the National Board Inspection Code (NBIC) permit the use of local PWHT around nozzles or other pressure boundary repairs or alterations. Additionally, Welding Research Council (WRC) Bulletin 452 [1] offers detailed guidance relating to local PWHT and compares some of the Code-based methodologies for implementing local PWHT on pressure retaining equipment. Specifically, local PWHT methodologies provided in design Codes: ASME Section VIII Division 1 [2] and Division 2 [3], ASME Section III Subsection NB [4], British Standard 5500 [5], Australian Standard 1210 [6], and repair Codes: American Petroleum Institute (API) 510 [7] and NBIC [8] are discussed and compared in this study. While spot PWHT may be appropriate in certain cases, if the soak, heating, and gradient control bands are not properly sized and positioned, it can lead to permanent vessel distortion or detrimental residual stresses that can increase the likelihood of in-service crack initiation and possible catastrophic failure due to unstable flaw propagation. It is essential to properly engineer local or spot PWHT configurations to ensure that distortion, cracking of adjacent welds, and severe residual stresses are avoided. In some cases, this may require advanced thermal-mechanical finite element analysis (FEA) to simulate the local PWHT process and to predict the ensuing residual stress state of the repaired area. This paper investigates several case studies of local PWHT configurations where advanced, three-dimensional FEA is used to simulate the thermal-mechanical response of the repaired region on a pressure vessel and to optimize the most ideal PWHT arrangement. Local plasticity and distortion are quantified using advanced non-linear elastic-plastic analysis. Commentary on the ASME and NBIC Code-specified local PWHT requirements is rendered based on the detailed non-linear FEA results, and recommended good practice for typical local PWHT configurations is provided. Advanced computational simulation techniques such as the ones employed in this investigation offer a means for analysts to ensure that local PWHT configurations implemented following equipment repairs will not lead to costly additional damage, such as distortion or cracking that can ultimately prolong equipment downtime.


1996 ◽  
Vol 118 (4) ◽  
pp. 429-433
Author(s):  
H. Chen ◽  
J. Jin ◽  
J. Yu

Results from finite element analysis were used to show that the stress index kσ and the nondimensionalized highly stressed hub length kh of a flat head with a round corner in a pressure vessel subjected to internal pressure are functions of three dimensionless parameters: λ ≡ h/dt, η ≡ t/d, and ρ ≡ r/t. Approximate formulas for estimating kσ and kh from λ, η, and ρ p are given. The formulas can be used for determining a suitable fillet radius for a flat head in order to reduce the fabricating cost and to keep the stress intensity at the fillet under an acceptable limit.


2014 ◽  
Vol 598 ◽  
pp. 194-197
Author(s):  
Hong Jun Li ◽  
Qiang Ding ◽  
Xun Huang

Stress linearization is used to define constant and linear through-thickness FEA (Finite Element Analysis) stress distributions that are used in place of membrane and membrane plus bending stress distributions in pressure vessel Design by Analysis. In this paper, stress linearization procedures are reviewed with reference to the ASME Boiler & Pressure Vessel Code Section VIII Division 2 and EN13445. The basis of the linearization procedure is stated and a new method of stress linearization considering selected stress tensors for linearization is proposed.


2012 ◽  
Vol 184-185 ◽  
pp. 538-541
Author(s):  
Dong Su Zhang ◽  
Zhao Long Liu ◽  
Gan Lin Cheng ◽  
Hui Liu ◽  
Meng Xu

Premixed abrasive water jet abrasive tank has always been under static load in the course of their work, belonging to the pressure vessel. In view of the importance of the pressure vessel safety issues, the traditional design was conservative, and the shell is relatively thick and heavy. This paper uses simulation (finite element analysis module in solidworks)to do finite element analysis of the abrasive tank. In guarantee under the condition of its strength, reducing the shell weight of abrasive tank as much as possible can help to achieve the purpose of lightweight design and saving energy, reducing cost and price.


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