Design of Threaded Closures for High Pressure Screw Plug Heat Exchangers Designed to ASME Section VIII Div. 2

2017 ◽  
Author(s):  
Haresh K. Sippy ◽  
Dipak K. Chandiramani
Keyword(s):  
High Pressure ◽  
Heat Exchangers ◽  
Pressure Vessels ◽  
Typical Application ◽  
High Pressure And Temperature ◽  
Heat Transfer Efficiency ◽  
Allowable Stresses ◽  
Section Viii ◽  
Screw Threads ◽  
Good Access

Threaded closures for pressure vessels have been in use for decades. Much work has been done to develop safe threaded closures. Threaded closures are very advantageous when there is a need for opening the vessel at intervals for maintenance purposes. Heat Exchangers are a typical application where there is a need for opening the vessel to get good access to the inside and outside of the tubes for mechanical cleaning, thus maintaining heat transfer efficiency. These are known as Screw Plug Heat Exchangers and are basically U-tube heat exchangers. The tube side normally operates at high pressure and temperature and is closed by a threaded end closure. Two problems are often encountered in screw plug heat exchangers. These are: 1. Leakage through the gasket at the tubesheet causing intermixing of shell side and tube side fluids, which is unacceptable 2. Jamming of the threaded plug due to deformation of channel barrel In an earlier paper (PVP2016-63137) these problems were studied for a vessel designed to ASME Section VIII Div. 1. It was found that leakage through the tubesheet gasket could be eliminated by changing the gasket to a grooved metal gasket with covering layers as defined in ASME B16.20. Preventing leakage from the tubesheet gasket is extremely necessary to get the ultra-low sulphur requirements for clean fuel. In the work reported in this paper, a procedure for obtaining leak-free performance on a vessel designed to ASME Section VIII Div. 2 was developed and verified using a prototype. Code formulae for calculation of thickness of various parts normally consider only the need to limit the component stress to be within allowable limits defined in the Code. Allowable stresses for Section VIII Div. 2 construction may be about 18 % higher than the allowable stress for Section VIII Div. 1 construction at design temperature, thereby allowing thinner sections for the same design conditions. As the thinner sections would deform more, the likelihood of jamming of the end cover could be more severe in ASME Section VIII Div. 2 constructions. Hence this study was additionally undertaken to verify the adequacy of the earlier proposed design methodology, i.e., use of an additional steel ring shrunk fit to the end of the channel to prevent flaring of the channel and jamming of screw threads, for Section VIII Div. 2 constructions.

An Improved Design of Threaded Closures for Screw Plug (Breech Lock) Heat Exchangers

2016 ◽  
Author(s):  
Haresh K. Sippy ◽  
Dipak K. Chandiramani
Keyword(s):  
Thermal Expansion ◽  
Heat Exchangers ◽  
Tube Bundle ◽  
Pressure Vessels ◽  
Typical Application ◽  
Heat Transfer Efficiency ◽  
Shrink Fitting ◽  
Shell And Tube ◽  
Improved Design ◽  
Screw Threads

Threaded closures for pressure vessels have been in use for decades. Much work has been done to develop convenient, safe and economical threaded closures. Threaded closures are used when there is a need for opening the vessel either for maintenance or as part of its operation. Heat Exchangers are a typical application where there is a need for opening the vessel and cleaning the tubes at regular intervals to maintain the heat transfer efficiency. These are known as Breech Lock or Screw Plug Exchangers. These are basically U-tube exchangers. The channel side operates at high temperature and pressure and it has a threaded end closure. In some designs, the shell side may also be at high pressure. The tube bundle is removable without having to dismantle the channel or disconnect the nozzles from the pipeline. Thus screw plug exchangers help to reduce fabrication cost and reduce time for in-service maintenance. The major problem encountered with the use of such end closures are 1) Jamming of the threaded plug, due to deformation of the channel barrel. Thus the opening of the end closure by unscrewing becomes a difficult task. With the increase in operating temperatures and pressures, the problems become more severe, due to which, users are not inclined to use these type of end closures. A study was undertaken to assess the reasons for bulging of the end of the channel which caused jamming of the screw threads and also for leakage through the gasket. By shrink fitting a ring over the end of the channel, the deformation was reduced, enabling easy opening of the cover. 2) The leakage through the gasket between the shell and tubesheet, causing the intermixing of shell and tube-side fluids. This on analysing was found that the additional forces were acting on the gasket due to thermal expansion of the internals. This led to changing to a gasket that could withstand the forces and pressure. Leakage through the gasket was prevented by analysing the additional forces acting on the gasket due to thermal expansion of the internals and changing to a gasket that could withstand the forces and pressure.

Design Formulas of Blind End Closures for High Pressure Vessels

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
R. D. Dixon ◽  
E. H. Perez
Keyword(s):  
High Pressure ◽  
Fatigue Life ◽  
Maximum Stress ◽  
Accurate Determination ◽  
Pressure Vessels ◽  
Stress Distributions ◽  
Fatigue And Fracture ◽  
Asme Code ◽  
Section Viii

The available design formulas for flat heads and blind end closures in the ASME Code, Section VIII, Divisions 1 and 2 are based on bending theory and do not apply to the design of thick flat heads used in the design of high pressure vessels. This paper presents new design formulas for thickness requirements and determination of peak stresses and stress distributions for fatigue and fracture mechanics analyses in thick blind ends. The use of these proposed design formulas provide a more accurate determination of the required thickness and fatigue life of blind ends. The proposed design formulas are given in terms of the yield strength of the material and address the fatigue strength at the location of the maximum stress concentration factor. Introduction of these new formulas in a nonmandatory appendix of Section VIII, Division 3 is recommended after committee approval.

Square Root 3: Background to the New Design Margin for High Pressure Vessels

2005 ◽  
Author(s):  
Jan Keltjens ◽  
Philip Cornelissen ◽  
Peter Koerner ◽  
Waldemar Hiller ◽  
Rolf Wink
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
Design Code ◽  
Code Change ◽  
Section Viii ◽  
Background Material ◽  
Practical Information ◽  
High Pressure Equipment ◽  
Design Margin

The ASME Section VIII Division 3 Pressure Vessel Design Code adopted in its 2004 edition a significant change of the design margin against plastic collapse. There are several reasons and justifications for this code change, in particular the comparison with design margins used for high pressure equipment in Europe. Also, the ASME Pressure Vessel Code books themselves are not always consistent with respect to design margin. This paper discusses not only the background material for the code change, but also gives some practical information on when pressure vessels could be designed to a thinner wall.

Comparison Between the ASME BPVC Section VIII Division 3 and the Chinese Regulation TSG 21-2016 With Regard to the Design of High Pressure Vessels

2018 ◽  
Author(s):  
David Fuenmayor ◽  
Rolf Wink ◽  
Matthias Bortz
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
Chinese Economy ◽  
High Pressure Vessel ◽  
Safety Technology ◽  
Section Viii ◽  
Design Construction

There are numerous codes covering the design, manufacturing, inspection, testing, and operation of pressure vessels. These national or international codes aim at providing assurance regarding the safety and quality of pressure vessels. The development of the Chinese economy has led to a significant increase in the number of installed high-pressure vessels which in turn required a revision of the existing regulations. The Supervision Regulation on Safety Technology for Stationary Pressure Vessel TSG 21-2016 superseded the existing Super-High Pressure Vessel Safety and Technical Supervision Regulation TSG R0002-2005 in October of 2016. This new regulation covers, among others, the design, construction, and inspection of pressure vessels with design pressures above 100 MPa. This paper provides a technical comparison between the provisions given in TSG 21-2016 for super-high pressure vessels and the requirements in ASME Boiler and Pressure Vessel Code Section VIII Division 3.

Application of ASME Section VIII Division 3 Design Requirements to Offshore High Pressure Equipment

2013 ◽  
Author(s):  
J. Robert Sims
Keyword(s):  
High Pressure ◽  
Oil And Gas ◽  
Local Strain ◽  
Pressure Vessels ◽  
Stress Concentrations ◽  
Section Viii ◽  
Design Requirements ◽  
Offshore Oil And Gas ◽  
Materials Used ◽  
Offshore Oil

Offshore oil and gas wells are being drilled into formations that have pressures up to 200 MPa (30,000 psi) and temperatures over 175°C (350°F). Most of the existing API Standards for pressure equipment, such as valves and blow out preventers (BOPs), are limited to pressures of about 100 MPa (15,000 psi). The design requirements in ASME Section VIII Division 3, Alternative Rules for Construction of High Pressure Vessels (Div. 3), can be adapted for the design of this equipment with some modifications. Since the strength of the materials used in these applications is limited due to environmental cracking concerns, it is necessary to accept some local yielding in areas of stress concentrations. Therefore, it is particularly important to apply the elastic-plastic analysis requirements in Div. 3 with appropriate limits on local strain as well as the robust fracture mechanics based fatigue analysis requirements. Paper published with permission.

Overview of Revisions to the ASME Boiler and Pressure Vessel Code Section VIII Division 3 for the 2017 Edition and Near Future

2017 ◽  
Author(s):  
Daniel Peters ◽  
Gregory Mital ◽  
Adam P. Maslowski
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
Central Area ◽  
Local Strain ◽  
Pressure Vessels ◽  
Conformity Assessment ◽  
Inspection Planning ◽  
Section Viii ◽  
American Society ◽  
Rules Changes

This paper provides an overview of the significant revisions pending for the upcoming 2017 edition of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) Section VIII Division 3, Alternative Rules for Construction of High Pressure Vessels, as well as potential changes to future editions under consideration of the Subgroup on High Pressure Vessels (SG-HPV). Changes to the 2017 edition include the removal of material information used in the construction of composite reinforced pressure vessels (CRPV); this information has been consolidated to the newly-developed Appendix 10 of ASME BPVC Section X, Fiber-Reinforced Plastic Pressure Vessels. Similarly, the development of the ASME CA-1, Conformity Assessment Requirements standard necessitated removal of associated conformity assessment information from Section VIII Division 3. Additionally, requirements for the assembly of pressure vessels at a location other than that listed on the Certificate of Authorization have been clarified with the definitions of “field” and “intermediate” sites. Furthermore, certain design related issues have been addressed and incorporated into the current edition, including changes to the fracture mechanics rules, changes to wires stress limits in wire-wound vessels, and clarification on bolting and end closure requirements. Finally, the removal of Appendix B, Suggested Practice Regarding Post-Construction Requalification for High Pressure Vessels, will be discussed, including a short discussion of the new appendix incorporated into the updated edition of ASME PCC-3, Inspection Planning Using Risk Based Methods. Additionally, this paper discusses some areas in Section VIII Division 3 under consideration for improvement. One such area involves consolidation of material models presented in the book into a central area for easier reference. Another is the clarification of local strain limit analysis and the intended number and types of evaluations needed for the non-linear finite element analyses. The requirements for test locations in prolongations on forgings are also being examined as well as other material that can be used in testing for vessel construction. Finally, a discussion is presented on an ongoing debate regarding “occasional loads” and “abnormal loads”, their current evaluation, and proposed changes to design margins regarding these loads.

Development of Japanese High Pressure Vessel Standard HPIS C106 With ASME Section VIII Division 3

2017 ◽  
Author(s):  
Susumu Terada
Keyword(s):  
High Pressure ◽  
Crystal Growth ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
Design Code ◽  
Isostatic Pressing ◽  
High Pressure Vessel ◽  
Cyclic Operation ◽  
Section Viii

Many high pressure vessels are used in isostatic pressing, polyethylene process and crystal growth application. The design condition of these high pressure vessels becomes more severe in pressure, temperature and cyclic operation. It was desired that design code for such high pressure vessels be issued enabling more reasonable design than ASME Section VIII Div.1 and Div.2. Against above request, ASME Sec. VIII Div.3 was issued in 1997. While in Japan the subcommittee for high pressure vessels in HPI was started in October 1997 in order to issue the Japanese code for high pressure vessels. At first the background of ASME Div.3 was investigated and then “Rules for Construction of High Pressure Vessels: HPIS C 106” was issued in 2005. That was some differences from ASME Div.3, because we considered that ASME Div.3 should be modified. The author has also been appointed as a member of ASME SG-HPV Committee since 2003. The author has proposed some modification and addition of rules for ASME Div.3 since 2000 and most of them already have been approved and incorporated in ASME Div.3. The background of these modification and addition of rules are shown in this paper.

Leak-Before-Burst Testing of a High Pressure Tube

2002 ◽  
Author(s):  
Peter Koerner ◽  
Waldemar Hiller ◽  
Rolf Wink
Keyword(s):  
High Pressure ◽  
Failure Mode ◽  
Failure Modes ◽  
Pressure Vessels ◽  
Gas Release ◽  
Important Criterion ◽  
Design Code ◽  
Pressure System ◽  
Compressed Gas ◽  
Section Viii

High pressure systems like a LDPE-reactor may store a great amount of energy in the form of compressed gas. The way in which this energy is released in case of a failure is of paramount importance to the safety of the plant and its personnel. Catastrophic failure modes with a large gas release and possible metal splintering have to be avoided as far as technically possible. Therefore the failure mode needs to be analysed during the design of a high pressure system and taken into account. One important criterion for a safe pressure component is that a leak-before-burst behaviour can be ensured. This paper discusses the requirements for demonstration of this failure mode according to the design code for high pressure vessels ASME section VIII division 3. A full scale parts test using a DN-80, PN-3500 reactor tube section of a tubular LDPE-plant has been used to compare the code requirements with experimental results.

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