Research and Development of a Rubber O-Ring Sealing Device for High Pressure Vessels

Author(s):  
Fan Zhou ◽  
Zhiping Chen ◽  
Haigui Fan

An O-ring made of rubber exhibits excellent sealing performance with a wide range of applications. The highest sealing pressure can be up to 400MPa. The temperature ranges from −60 °C to 200 °C and the medium is low-corrosiveness. This paper proposes an O-ring sealing device for high pressure vessels, which can be opened and operated outside a cylinder. There are no bolts bearing the axial stress under the internal pressure load, and the sealing efficiency of this device is guaranteed by the dimension chain. The whole sealing device has no threaded connections except for the oriented screw which does not bear load under the working conditions. Based on this newly developed sealing device, a high pressure vessel with the design pressure of 60 MPa and the internal diameter of 700 mm used to simulate 6000 m deep sea environment is developed and investigated. This paper firstly introduces the rationale behind the design of the sealing structure for this high pressure vessel, and then discusses a finite element model of the cylinder end for this high pressure vessel and the stress classification method which is used to evaluate the safety of the critical sections. Lastly, the paper presents a set of experimental devices and a series of experiments which were carried out. The results show that the proposed sealing structure can be used in high pressure vessels. The results also verify the assumption of triangle contact pressure distribution between the shear ring and the cylinder end. It is hoped that this study will be of interest and value to researchers when they design the similar structures in the future.

Author(s):  
Zhiwei Chen ◽  
Tao Li ◽  
Guoyi Yang ◽  
Jinyang Zheng ◽  
Guide Deng

Abstract GB/T 34019-2017 “Ultra High Pressure Vessels” is the most important national standard that applies to pressure vessel which design pressure value is greater than or equal to 100MPa (14.5ksi). There is no standard for Ultra-high Pressure Vessel, Then this standard fills the gap in the standard system of pressure equipment in China. This paper mainly introduces the concept and main content of the new national standard, including the materials, design methods and nondestructive testing of ultra-high pressure vessel.


Author(s):  
David Fuenmayor ◽  
Rolf Wink ◽  
Matthias Bortz

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.


Author(s):  
Yu Xu ◽  
Kuao-John Young

Small size longitudinal holes are common in components of high pressure vessels. In fracture mechanics evaluation, longitudinal holes have not drawn as much attention as cross-bores. However, longitudinal holes become critical at certain locations for such assessments because of high stress concentration and short distance to vessel component wall. The high stress concentration can be attributed to three parts: global hoop stress that is magnified by the existence of the hole, local stresses due to pressure in the hole, and crack face pressure. In high pressure vessel design, axisymmetric models are used extensively in stress analyses, and their results are subsequently employed to identify critical locations for fracture mechanics evaluation. However, axisymmetric models ignore longitudinal holes and therefore cannot be used to identify the critical location inside the holes. This paper is intended to highlight the importance of including longitudinal holes in fracture mechanics evaluation, and to present a quick and effective way of evaluating high stress concentration at a longitudinal hole using the combined analytical solutions and axisymmetric stress analysis results, identifying critical locations and conducting fracture mechanics evaluation.


Author(s):  
Susumu Terada

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.


2010 ◽  
Vol 97-101 ◽  
pp. 2603-2606
Author(s):  
Jian Hua Rao ◽  
Q.F. Shen ◽  
C. Wang

To improve the working performance of the compound rings high-pressure vessel, the different assembly and structural parameters during the process of radial and axial preloading have been analyzed with the finite element method. The simulation analysis on the assembly process of room temperature press-fitting has been carried out based on the theory of contact problem with friction, and it is found that the tangential compressive prestress is uneven under the influence of friction coefficient and conicity of fitting surfaces. The main effect factors of horizontal fracture of cemented carbide core are also analyzed. Furthermore, the results of reducing the axial stress of core by different ways of applying end pressure are compared. These studies provide the guidance for the improvement in design and manufacture of compound rings.


Author(s):  
Takayasu Tahara

Pressure equipment in refinery and petrochemical industries in Japan has been getting old, mostly more than 30 years in operation. Currently, the Japanese regulations for pressure equipment in service are the same as those in existence during the fabrication of the pressure equipment. Accordingly, there is an immediate need for an up to date more advanced “Fitness For Service” (FFS) evaluation requirements for pressure equipment. In order to introduce the latest FFS methodologies to Japanese industries, the High Pressure Institute of Japan (HPI) has organized two task groups. One is a working group for development of a maintenance standard for non-nuclear industries. Its prescribed code “Assessment procedure for crack-like flaws in pressure equipment” is for conducting quantitative safety evaluations of flaws detected in common pressure equipment such as pressure vessels, piping, storage tanks. The other is a special task group to study of API RP579 from its drafting stage as a member of TG579. The FFS Handbook, especially for refinery and petrochemical industries, has been developed based on API RP579 with several modifications to meet Japanese pressure vessel regulations on April 2001. [1] It is expected that both the Standard and FFS handbook will be used as an exemplified standard with Japanese regulations for practical maintenance. This paper presents concepts of “Assessment procedure for crack-like flaws in pressure equipment” HPIS Z101, 2001 [2].


Author(s):  
Xin Ma ◽  
Zhongpei Ning ◽  
Honggang Chen ◽  
Jinyang Zheng

Ultra-High Pressure Vessel (UHPV) with self-protective Flat Steel Ribbons (FSR) wound and Tooth-Locked Quick-Actuating (TLQA) end closure is a new type of vessel developed in recent years. When the structural parameters of its TLQA and Buttress Thread (BT) end closure are determined using the ordinary engineering design method, Design by Analysis (DBA) shows that the requirement on fatigue life of this unique UHPV could hardly be satisfied. To solve the above problem, an integrated FE modeling method has been proposed in this paper. To investigate the fatigue life of TLQA and BT end closures of a full-scale unique UHPV, a three-dimensional (3-D) Finite Element (FE) solid model and a two-dimensional (2-D) FE axisymmetric model are built in FE software ANSYS, respectively., Nonlinear FE analysis and orthogonal testing are both conducted to obtain the optimum structure strength, in which the peak stress in the TLQA or BT end closure of the unique UHPV is taken as an optimal target. The important parameters, such as root structure of teeth, contact pressure between the pre-stressed collar and the cylinder end, the knuckle radius, the buttress thread profile and the local structure of the cylinder, are optimized. As a result, both the stress distribution at the root of teeth and the axial load carried by each thread are improved. Therefore, the load-carrying capacity of the end closure has been reinforced and the fatigue life of unique UHPV has been extended.


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