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

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.

1979 ◽  
Vol 101 (1) ◽  
pp. 9-15 ◽  
Author(s):  
K. P. Singh

“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.


Author(s):  
Warren Brown ◽  
Stewart Long

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.


Author(s):  
Warren Brown

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.


2011 ◽  
Vol 133 (06) ◽  
pp. 48-52
Author(s):  
Edward Hayman ◽  
Clyde Neely

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.


2006 ◽  
Vol 46 (1) ◽  
pp. 603
Author(s):  
R. Noble

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.


2020 ◽  
Vol 14 (3) ◽  
pp. 7141-7151 ◽  
Author(s):  
R. Omar ◽  
M. N. Abdul Rani ◽  
M. A. Yunus

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.


2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Keita Ogawa ◽  
Satoshi Fukuta ◽  
Kenji Kobayashi

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.


2010 ◽  
Vol 02 (02) ◽  
pp. 281-304 ◽  
Author(s):  
N. PEYRET ◽  
J.-L. DION ◽  
G. CHEVALLIER ◽  
P. ARGOUL

The friction between interfaces at bolted joints plays a major role in the damping of structures. This paper deals with the energy losses caused by micro-slips in the joints. The aim of this study is to define in an analytical way these energy dissipation mechanisms which we examine through the analysis of a new benchmark: the flexural vibration of a clamped-clamped beam with original positioning of the interfaces. The joints exhibit the behavior of an interface under constant and uniform normal stress. The stress and strain values are computed at the joints under the assumption of quasi-static motion. This model allows us to understand the evolution of the slip and stick regions along the joint interfaces during the loading process. The expressions of the strain and stress fields during each phase of the loading process are derived. These lead to the quantification of the dissipated energy within the interface. Using this formula, a nonlinear loss factor can then be computed. In the final part of the paper, the dynamic response of the beam is calculated using this nonlinear loss factor.


Author(s):  
A. A. Tsviliy-Buklanova

The article is devoted to the relevance of the development and adoption of the Concept for the development of the Contract System of the Ministry of Internal Affairs of Russia in order to increase the efficiency of using budget funds and eliminate corruption risks in the implementation of public procurement. The regulatory framework of federal and departmental level was considered, attention was paid to practical aspects of procurement of goods, works and services for the needs of internal affairs bodies, issues of regulation and control are reflected. Structural elements of the Concept, ways to improve the Contract System of the Ministry of Internal Affairs of Russia are proposed.


2021 ◽  
Author(s):  
Rashique Iftekhar Rousseau ◽  
Abdel-Hakim Bouzid ◽  
Zijian Zhao

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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