Acceptable Levels of Corrosion for Pressure Boundary Bolted Joints

2017 ◽  
Author(s):  
Warren Brown ◽  
Stewart Long
Keyword(s):  
Recent Work ◽  
Bolted Joints ◽  
Recent Analysis ◽  
Catastrophic Failure ◽  
Bolted Joint ◽  
High Level ◽  
Joint Integrity

This paper outlines recent work in the field of pressure boundary bolted joint integrity and the effect of corrosion on bolted joint components. It summarizes recent analysis and testing which determined the risk to joint integrity or catastrophic failure associated with corrosion of the joint components; bolts, nuts and flanges. The paper details, at a high level, the work performed and outlines the limits to corrosion that can be applied in the field for each component as an inspection limit to trigger planned replacement or emergency shut down.

Ultrasonic measurement of self-loosening in bolted joints

2011 ◽  
Vol 226 (7) ◽  
pp. 1869-1884 ◽  
Author(s):  
MB Marshall ◽  
R Lewis ◽  
T Howard ◽  
H Brunskill
Keyword(s):  
Steady State ◽  
Ultrasonic Measurement ◽  
Bolted Joints ◽  
Catastrophic Failure ◽  
Interface Pressure ◽  
Rapid Reduction ◽  
Contact Conditions ◽  
Joint Integrity ◽  
Clamping Pressure ◽  
Insight Into

Self-loosening of bolted joints in response to vibration can lead to the catastrophic failure of a range of engineering components and structures. Many techniques employed to study this phenomenon focus on directly measuring the pre-load remaining in the bolt itself, and offer little insight into the behaviour of the clamped interface. In this study, a non-intrusive ultrasonic reflection-based technique is used to first characterize interface pressure in the joint, and then determine the rate at which relaxation occurs. A key advantage of the technique is that it does not require the modification of the contact conditions, and rather utilizes the spring-like behaviour of a rough surface interface when subject to ultrasonic excitation. A series of different bolt torques were investigated, along with the inclusion of both plain and spring washers under the bolt head. All test samples were subjected to an oscillating fixed–displacement vibration cycle. An initial rapid reduction in interface clamping pressure was observed, followed by a more steady-state period. Increasing bolt torque was seen to enhance joint integrity, whereas both the plain and spring washers showed little improvement. The spring washer was observed to extend the secondary steady-state phase of loosening, though as the majority of pre-load was removed prior to this period any change was largely unbeneficial.

Bending Effect in Concentric Bolted Joints Under Transverse Load

2013 ◽  
Author(s):  
Yosef Amir ◽  
Saravanakumar Iyyanar ◽  
Aravind Devali ◽  
Muniratnam Kumar
Keyword(s):  
Closed Form ◽  
Potential Risk ◽  
Closed Form Solution ◽  
Form Solution ◽  
Bolted Joints ◽  
Transverse Load ◽  
Catastrophic Failure ◽  
Bending Stress ◽  
Bolted Joint ◽  
Bending Effect

Bending stress calculation in eccentric bolted joints is a well-known process in the design of bolted joints. However, in a concentric bolted joint with transverse load, the existence of bending stress is generally not considered as critical. But in reality, there is a possibility of catastrophic failure of the bolt occurring in a concentric bolted joint as a result of the bending stress even before the joint looseness or before the bolt fracture under tension. The aim of this paper is to propose a closed form solution to predict the potential risk of this failure that could be developed particularly at moderate preload of the bolt. Three concentric bolted joint cases with M12, M10 and M8 with transverse load and external tension load were investigated; FEA and experimental results validated the closed form calculation.

Study of Bolted Joint Integrity and Inter-Tube-Pass Leakage in U-Tube Heat Exchangers—Part I: Analysis

1979 ◽  
Vol 101 (1) ◽  
pp. 9-15 ◽  
Author(s):  
K. P. Singh
Keyword(s):  
Heat Exchangers ◽  
Structural Characteristics ◽  
Comprehensive Analysis ◽  
Bolted Joints ◽  
Design Evaluation ◽  
Bolted Joint ◽  
Design Strategies ◽  
Analysis Technique ◽  
Tube Type ◽  
Joint Integrity

“Three element bolted joints,” consisting of an unstayed tubesheet sandwiched between two tapered hub flanges, find extensive use in U-tube type heat exchangers. A comprehensive analysis technique is herein developed to investigate the structural characteristics of such joints. Design strategies to reduce stress levels in the tubesheet and the flanges are proposed. In particular, the concept of “controlled” metal-to-metal contact beyond the bolt circle between the mating surfaces is introduced and explored in depth. The solution is readily programmed on a digital computer for application in analysis oriented design evaluation and optimization studies.

Efficient Assembly of Pressure Vessel Bolted Joints

2004 ◽  
Author(s):  
Warren Brown
Keyword(s):  
Pressure Vessel ◽  
Experimental Results ◽  
Bolted Joints ◽  
Effect Of Temperature ◽  
Bolted Joint ◽  
Joint Integrity ◽  
Selection Of ◽  
Joint Assembly

This paper details the results of recent testing and experience into the assembly of bolted joints. Pressure boundary bolted joint assembly procedures are examined and details are presented that result in a reduction in the required effort to assemble any given joint by more than 50%. The selection of correct assembly load levels is addressed and suggestions for joint integrity improvement are made. Experimental results are also presented on the use of bolt lubricants and the effect of temperature on the lubricant properties.

Study of Bolted Joint Integrity and Inter-Tube-Pass Leakage in U-Tube Heat Exchangers—Part II: Applications

1979 ◽  
Vol 101 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Krishna P. Singh
Keyword(s):  
Heat Exchangers ◽  
Bolted Joints ◽  
Stress Fields ◽  
Design Codes ◽  
Structural Elements ◽  
Bolted Joint ◽  
Design Concepts ◽  
Leakage Flows ◽  
Effective Use ◽  
Joint Integrity

The formulation for “Three Element Bolted Joints” pertinent to removable bundle U-tube Heat Exchangers developed in an earlier work is herein extended to compute inter-tube-pass leakage rates. Design concepts aimed to reduce the leakage flows are proposed and their impact on the stress fields in the structural elements (tubesheet and flanges) is studied. Evaluation of stresses in the tubesheet and mating flanges in a typical example problem reveals potentially severe inadequacies in the existing design codes and standards. Practically feasible remedial design measures are proposed and examined as to their merits and limitations. In particular, the concept of “controlled” metal-to-metal contact beyond the bolt circle, introduced in an earlier work, is explored in depth. Effective use of this concept is shown to significantly alleviate stresses in the elements of the joints.

scholarly journals Solving the Puzzle of Bolted Joints

2011 ◽  
Vol 133 (06) ◽  
pp. 48-52
Author(s):  
Edward Hayman ◽  
Clyde Neely
Keyword(s):  
Best Practices ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Flange Joint ◽  
Unit Load ◽  
Bolt Stress ◽  
Torque Values ◽  
Bolted Flange ◽  
Joint Integrity ◽  
Joint Assembly

This article discusses the various ways of solving the puzzle of bolted joint assembly. In 2001, The PCC-1-2000 Guidelines for Pressure Boundary Bolted Flange Joint Assembly presented with knowledge and practices specific to the assembly of bolted flange joints. The puzzle solution that came from this box was the most definitive to date and allowed those dealing with bolted joints to assemble the variables by methods that had been used successfully for many years by many people. This document is helping people across industry not only to assemble bolted flange joints, but also to establish joint integrity programs, procedures, and best practices. PCC-1-2010 shifts the emphasis to gasket stress and gasket type and provides instruction and information pertinent to bolt torque values. The 2010 document contains, for instance, a whole section on bolt stress—the unit load that should be put on the bolts—and includes tables as well.

INTEGRITY OF BOLTED JOINTS: HYDROCARBON LEAK REDUCTION BY JOINT-INTEGRITY MANAGEMENT

2006 ◽  
Vol 46 (1) ◽  
pp. 603
Author(s):  
R. Noble
Keyword(s):  
Environmental Performance ◽  
Welded Joint ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Petroleum Production ◽  
Material Control ◽  
Product Loss ◽  
Integrity Management ◽  
Joint Integrity ◽  
Production Facilities

Bolted joints are very common in petroleum production facilities. Whereas extensive controls are applied to the production of a welded joint—in terms of material control and specification, control and competence of the welder, and verification of the integrity of the weld—this is not the case for bolted joints. The consequences of failure of a welded joint and a bolted joint, however, are similar and potentially catastrophic if the contents of the pipeline or vessel are hydrocarbons under pressure. This paper discusses the main issues in producing and maintaining a leak-free bolted joint and makes the case for establishing industry-wide standards for the management of bolted joints that are equally as stringent as those applied to welded joints.Implementing such a system, whilst improving and assuring the safety and environmental performance of an asset, will also reduce costs due to rework, product loss, schedule slippage and production downtime.

Representation of bolted joints in a structure using finite element modelling and model updating

2020 ◽  
Vol 14 (3) ◽  
pp. 7141-7151 ◽  
Author(s):  
R. Omar ◽  
M. N. Abdul Rani ◽  
M. A. Yunus
Keyword(s):  
Finite Element ◽  
Dynamic Behaviour ◽  
Model Updating ◽  
Complex Structure ◽  
Bolted Joints ◽  
Model Parameters ◽  
Fe Model ◽  
Bolted Joint ◽  
Fe Modelling ◽  
Joint Structure

Efficient and accurate finite element (FE) modelling of bolted joints is essential for increasing confidence in the investigation of structural vibrations. However, modelling of bolted joints for the investigation is often found to be very challenging. This paper proposes an appropriate FE representation of bolted joints for the prediction of the dynamic behaviour of a bolted joint structure. Two different FE models of the bolted joint structure with two different FE element connectors, which are CBEAM and CBUSH, representing the bolted joints are developed. Modal updating is used to correlate the two FE models with the experimental model. The dynamic behaviour of the two FE models is compared with experimental modal analysis to evaluate and determine the most appropriate FE model of the bolted joint structure. The comparison reveals that the CBUSH element connectors based FE model has a greater capability in representing the bolted joints with 86 percent accuracy and greater efficiency in updating the model parameters. The proposed modelling technique will be useful in the modelling of a complex structure with a large number of bolted joints.

scholarly journals Experimental study of lateral resistance of bolted joints using Japanese cedar (Cryptomeria japonica) treated with resin impregnation

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Keita Ogawa ◽  
Satoshi Fukuta ◽  
Kenji Kobayashi
Keyword(s):  
Short Pulse ◽  
Japanese Cedar ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Yield Load ◽  
Short Pulse Laser ◽  
Resin Impregnation ◽  
Lateral Resistance ◽  
Ultraviolet Wavelength ◽  
Resistance Performance

Abstract The development of wooden joints possessing high resistance performance has become an important issue for the construction of newer buildings. This study attempts to strengthen the lateral resistance of bolted joints using the previously reported plasticizing technique. This technique consists of two processing stages: incising the surface of the wood using an ultraviolet wavelength short-pulse laser and impregnating the resin into the incised area. This technique makes it possible to plasticize only a local part of the wood surface. Bolted joint specimens were assembled using plasticized wood around the bolt hole, and the lateral tests were conducted. Acrylic monomer and urethane prepolymer were used as the impregnating resins and their incision depths were set as 4 and 10 mm. When the lateral load acted parallel to the grain, changes in the lateral resistance characteristics were observed, especially for the stiffness and yield load. For example, when acryl was used, and the incision depth was 10 mm, an increment of 73% in the yield load was observed, as compared to the non-impregnated specimens. The specimen groups impregnated with acryl exhibited greater changes in their properties than those using urethane. When loaded perpendicular to the grain, an increase in properties were observed; however, these increments were lower than those of the groups loaded parallel to the grain.

Accurate Evaluation of Bolt and Clamped Members Stiffnesses Of Bolted Joints

2021 ◽  
Author(s):  
Rashique Iftekhar Rousseau ◽  
Abdel-Hakim Bouzid ◽  
Zijian Zhao
Keyword(s):  
Finite Element ◽  
Joint Stiffness ◽  
Element Model ◽  
Fe Analysis ◽  
Bolted Joints ◽  
Analytical Models ◽  
Fe Modeling ◽  
Bolted Joint ◽  
A New Technique ◽  
External Loads

Abstract The axial stiffnesses of the bolt and clamped members of bolted joints are of great importance when considering their integrity and capacity to withstand external loads and resist relaxation due to creep. There are many techniques to calculate the stiffnesses of the joint elements using finite element (FE) modeling, but most of them are based on the displacement of nodes that are selected arbitrarily; therefore, leading to inaccurate values of joint stiffness. This work suggests a new method to estimate the stiffnesses of the bolt and clamped members using FE analysis and compares the results with the FE methods developed earlier and also with the existing analytical models. A new methodology including an axisymmetric finite element model of the bolted joint is proposed in which the bolts of different sizes ranging from M6 to M36 are considered for the analysis to generalize the proposed approach. The equivalent bolt length that includes the contribution of the thickness of the bolt head and the bolt nominal diameter to the bolt stiffness is carefully investigated. An equivalent bolt length that accounts for the flexibility of the bolt head is proposed in the calculation of the bolt stiffness and a new technique to accurately determine the stiffness of clamped members are detailed.

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