Design Formulas of Blind End Closures for High Pressure Vessels

Author(s):  
R. D. Dixon ◽  
E. H. Perez

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 non-mandatory appendix of Section VIII, Division 3 is recommended after committee approval.

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
R. D. Dixon ◽  
E. H. Perez

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.


Author(s):  
Kang Xu ◽  
Mahendra Rana ◽  
Maan Jawad

Abstract Layered pressure vessels provide a cost-effective solution for high pressure gas storage. Several types of designs and constructions of layered pressure vessels are included in ASME BPV Section VIII Division 1, Division 2 and Division 3. Compared with conventional pressure vessels, there are two unique features in layered construction that may affect the structural integrity of the layered vessels especially in cyclic service: (1) Gaps may exist between the layers due to fabrication tolerances and an excessive gap height introduces additional stresses in the shell that need to be considered in design. The ASME Codes provide rules on the maximum permissible number and size of these gaps. The fatigue life of the vessel may be governed by the gap height due to the additional bending stress. The rules on gap height requirements have been updated recently in Section VIII Division 2. (2) ASME code rules require vent holes in the layers to detect leaks from inner shell and to prevent pressure buildup between the layers. The fatigue life may be limited by the presence of stress concentration at vent holes. This paper reviews the background of the recent code update and presents the technical basis of the fatigue design and maximum permissible gap height calculations. Discussions are made in design and fabrication to improve the fatigue life of layered pressure vessels in cyclic service.


Author(s):  
Michael D. Mann

Design guidance for high pressure components, has undergone a dramatic change with the release of ASME Section VIII division 3 pressure vessel code. For the first time, a thorough design criteria is available for design of thick wall pressure vessels. The most critical components of a design are safety and reliability. Ultra high-pressure vessels, in most cases, do not have an “infinite” life. The design must therefore be “leak before break” and a design cycle life must be specified. This paper looks at the effects of fatigue on commercial high-pressure tubing under tri-axial fatigue. The tubing investigated is 316 stainless steel 9/16″ and 3/8″ diameter 4100 bar (60,000 psi) tubing. The testing was performed using a tri-axial fatigue machine originally designed by Dr. B. Crossland, Dr. J. L. M. Morrison and Dr. J. S. C. Perry in 1960 and upgraded by the Author. This investigation compares the fatigue life prediction per KD3 in the ASME pressure vessel code Section VIII division 3 and actual test results from the fatigue machine. This verification gives important reliability data for commercial hardware used in high-pressure piping.


Author(s):  
Susumu Terada ◽  
Masato Yamada ◽  
Tomoaki Nakanishi

9Cr-1Mo-V steels (Gr. 91), which has an excellent performance at high temperature in mechanical properties and hydrogen resistance, has been used for tubing and piping materials in power industries and it can be a candidate material for high pressure vessels for high temperature processes in refining industries. The current Section VIII Division 2 of ASME code does not permit method A of paragraph 5.5.2.3 to be used for the exemption from fatigue analysis for Gr. 91 steels due to limitation of specified minimum tensile strength (585 MPa > 552 MPa). Method B of paragraph 5.5.2.4 also can’t be used because it requires the use of the fatigue curve which is limited to 371 °C lower than the needed temperature. Therefore new rules for fatigue evaluation of Gr. 91 steels at temperatures greater than 371 °C and less than 500 °C similar to CC 2605 for 2.25Cr-1Mo-0.25V(Gr. 22V) steels are necessary. This paper provides fatigue test results at 500 °C for Gr. 91 steels, the modification of CC 2605, sample inelastic analysis results for nozzles. Then, the new Code Case for Gr. 91 steels is proposed from these results.


Author(s):  
Robert E. Nickell ◽  
Thomas A. Duffey ◽  
Edward A. Rodriguez

Ductile failure criteria suitable for application to impulsively loaded high pressure vessels that are designed to the rules of the ASME Code Section VIII Division 3 are described and justified. The criteria are based upon prevention of load instability and the associated global failure mechanisms, and on protection against progressive distortion for multiple-use vessels. The criteria are demonstrated by the design and analysis of vessels that contain high explosive charges.


1967 ◽  
Vol 182 (1) ◽  
pp. 657-684 ◽  
Author(s):  
J. Spence ◽  
W. B. Carlson

Nozzles in cylindrical vessels have been of special interest to designers for some time and have offered a field of activity for many research workers. This paper presents some static and fatigue tests on five designs of full size pressure vessel nozzles manufactured in two materials. Supporting and other published work is reviewed showing that on the basis of the same maximum stress mild steel vessels give the same fatigue life as low alloy vessels. When compared on the basis of current codes it is shown that mild steel vessels may have five to ten times the fatigue life of low alloy vessels unless special precautions are taken.


1980 ◽  
Vol 102 (1) ◽  
pp. 98-106 ◽  
Author(s):  
G. J. Mraz ◽  
E. G. Nisbett

Steels at present included in Sections III and VIII of the ASME Boiler and Pressure Vessel Code severely limit its application for high-pressure design. An extension of the well-known AISI 4300 series low alloy steels has long been known as “Gun Steel.” These alloys, which are generally superior to AISI 4340, offer good harden-ability and toughness and have been widely used under proprietary names for pressure vessel application. The ASTM Specification A-723 was developed to cover these nickel-chromium-molybdenum alloys for pressure vessel use, and is being adopted by Section II of the ASME Boiler and Pressure Vessel Code for use in Section VIII, Division 2, and in Section III in Part NF for component supports. The rationale of the specification is discussed, and examples of the mechanical properties obtained from forgings manufactured to the specification are given. These include the results of both room and elevated temperature tension tests and Charpy V notch impact tests. New areas of applicability of the Code to forged vessels for high-pressure service using these materials are discussed. Problems of safety in operation of monobloc vessels are mentioned. Procedures for in-service inspection and determination of inspection intervals based on fracture mechanics are suggested.


2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Thomas A. Duffey ◽  
Kevin R. Fehlmann

Abstract High-explosive containment vessels are often designed for repeated use, implying predominately elastic material behavior. Each explosive test imparts an impulse to the vessel wall. The vessel subsequently vibrates as a result of the internal blast loading, with amplitude diminishing exponentially in time after a few cycles due to structural damping. Flaws present in the vessel, as well as new flaws induced by fragment impact during testing, could potentially grow by fatigue during these vibrations. Subsequent explosive tests result in new sequences of vibrations, providing further opportunity for flaws to grow by fatigue. The obvious question is, How many explosive experiments can be performed before flaws potentially grow to unsafe limits? Because ASME Code Case 2564-5 (Impulsively Loaded Pressure Vessels) has just been incorporated in Section VIII, Division 3 of the 2019 ASME Boiler and Pressure Vessel Code, evaluation of remaining life and fitness-for-service of explosive containment vessels now draws upon two interrelated codes and standards: ASME Section VIII-3 and API-579/ASME FFS-1. This paper discusses their implementation in determining the remaining life of dynamically loaded vessels that have seen service and are potentially damaged. Results of a representative explosive containment vessel are presented using actual flaw data for both embedded weld flaws and fragment damage. Because of the potentially large number of flaws that can be detected by modern nondestructive inspection methods, three simplifying assumptions and a procedure are presented for conservatively eliminating from further consideration the vast majority of the flaws that possess considerable remaining life.


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