Very thin torispherical pressure vessel ends under internal pressure: Test procedure and typical results

1981 ◽  
Vol 16 (3) ◽  
pp. 171-186 ◽  
Author(s):  
P Stanley ◽  
T D Campbell
Keyword(s):  
Stainless Steel ◽  
Internal Pressure ◽  
Elastic Stress ◽  
Test Procedure ◽  
Pressure Vessels ◽  
Time Dependent ◽  
Test Installation ◽  
Stress Indices ◽  
Pressure Test ◽  
Strain Data

Very thin cylindrical pressure vessels with torispherical end-closures have been tested under internal pressure until buckles developed in the knuckles of the ends. These were prototype vessels in an austenitic stainless steel. The preparation of the ends and the closed test vessels is outlined, and the instrumentation, test installation, and test procedure are described. Results are given and discussed for three typical ends (diameters 54, 81, and 108in.; thickness to diameter ratios 0.00237, 0.00158, and 0.00119). These include measured thickness and curvature distributions, strain data and the derived elastic stress indices, and pole deflection measurements. Some details of the observed time-dependent plasticity (or ‘cold creep’) are given. Details of two types of buckle that developed eventually in the vessel ends are also reported.

Stresses at openings in the torispherical end closure of a pressure vessel

1973 ◽  
Vol 8 (3) ◽  
pp. 191-199 ◽  
Author(s):  
R Kitching ◽  
K T Lau
Keyword(s):  
Stress Distribution ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
Elastic Stress ◽  
Pressure Vessels ◽  
Plastic Limit ◽  
Plastic Deformations ◽  
Elastic Stresses ◽  
Pressure Test ◽  
Plastic Limit Pressure

In the design of torispherical heads for cylindrical pressure vessels, it would often be desirable to position openings or branch connections in the vicinity of the toroidal portion of the shell, but from strength considerations it is normal practice to avoid doing so. An 18 inch inside-diameter model vessel of this type, with a nominal inside toroidal radius of 1.25 in was used for making strain and hence stress measurements in the shell due to internal pressure. Four unreinforced openings of 3 inch diameter were placed at different positions in the torispherical end and an elastic stress distribution for the shell around each opening was obtained. Distributions of elastic stresses in the shell were compared for the different opening positions with those in the unpierced shell in the toroidal region. Plastic deformations were measured in an over-pressure test and a plastic limit pressure was estimated.

A Noncyclic Method for Determination of Accumulated Strain in Stainless Steel 304 Pressure Vessels

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Gongfeng Jiang ◽  
Gang Chen ◽  
Liang Sun ◽  
Yiliang Zhang ◽  
Xiaoliang Jia ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
Peak Stress ◽  
Pressure Vessels ◽  
Experimental Results ◽  
Elastic Domain ◽  
Ratcheting Strain ◽  
Stainless Steel 304 ◽  
Accumulated Strain

Experimental results of uniaxial ratcheting tests for stainless steel 304 (SS304) under stress-controlled condition at room temperature showed that the elastic domain defined in this paper expands with accumulation of plastic strain. Both ratcheting strain and viscoplastic strain rates reduce with the increase of elastic domain, and the total strain will be saturated finally. If the saturated strain and corresponded peak stress of different experimental results under the stress ratio R ≥ 0 are plotted, a curve demonstrating the material shakedown states of SS304 can be constituted. Using this curve, the accumulated strain in a pressure vessel subjected to cyclic internal pressure can be determined by only an elastic-plastic analysis, and without the cycle-by-cycle analysis. Meanwhile, a physical experiment of a thin-walled pressure vessel subjected to cyclic internal pressure has been carried out to verify the feasibility and effectiveness of this noncyclic method. By comparison, the accumulated strains evaluated by the noncyclic method agreed well with those obtained from the experiments. The noncyclic method is simpler and more practical than the cycle-by-cycle method for engineering design.

A Single Technically Consistent Design Formula for the Thickness of Cylindrical Sections Under Internal Pressure

2006 ◽  
Vol 129 (1) ◽  
pp. 211-215 ◽  
Author(s):  
John D. Fishburn
Keyword(s):  
Experimental Data ◽  
Internal Pressure ◽  
State Of The Art ◽  
Original Data ◽  
Pressure Vessels ◽  
Time Dependent ◽  
Design Codes ◽  
Recent Developments ◽  
Current Design ◽  
Single Formula

Within the current design codes for boilers, piping, and pressure vessels, there are many different equations for the thickness of a cylindrical section under internal pressure. A reassessment of these various formulations, using the original data, is described together with more recent developments in the state of the art. A single formula, which can be demonstrated to retain the same design margin in both the time-dependent and time-independent regimes, is shown to give the best correlation with the experimental data and is proposed for consideration for inclusion in the design codes.

High-strain fatigue of stainless-steel cylinders: Experimental results and their application to pressure-vessel design

1967 ◽  
Vol 2 (4) ◽  
pp. 290-297 ◽  
Author(s):  
C Ruiz
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Static Pressure ◽  
Elastic Stress ◽  
High Strain ◽  
Pressure Vessels ◽  
Supplementary Information ◽  
Test Results ◽  
Stress Range ◽  
Fatigue Design

Thin cylindrical specimens, plain and with deep axial grooves, have been tested under pulsating pressure and under static pressure with cyclic axial straining. The test results, together with some supplementary information from other authors, show that Langer's method, based on an elastic-stress analysis, is applicable to the fatigue design of pressure vessels. Design curves for the establishment of the acceptable elastic-stress range corresponding to a given fatigue life are proposed. Attention is drawn to the limitations of Langer's method.

Time-Dependent Thermomechanical Creep Behavior of FGM Thick Hollow Cylindrical Shells Under Non-Uniform Internal Pressure

2017 ◽  
Vol 09 (06) ◽  
pp. 1750086 ◽  
Author(s):  
Mosayeb Davoudi Kashkoli ◽  
Khosro Naderan Tahan ◽  
Mohammad Zamani Nejad
Keyword(s):  
Internal Pressure ◽  
Shear Deformation Theory ◽  
Pressure Vessels ◽  
Functionally Graded ◽  
Time Dependent ◽  
Mechanical And Thermal Properties ◽  
Creep Analysis ◽  
Steady State Heat ◽  
Creep Constitutive Model ◽  
Walled Cylinder

In this paper, a theoretical solution for time-dependent thermo-elastic creep analysis of a functionally graded (FG) thick-walled cylinder based on the first-order shear deformation theory is presented. The cylinder is subjected to the non-uniform internal pressure and distributed temperature field due to steady-state heat conduction from inner to outer surface of the cylinder. Mechanical and thermal properties except Poisson’s ratio are assumed to vary along the thickness direction based on a power function. The creep constitutive model is on the basis of the Norton’s law. The effects of the temperature gradient and FG grading index on the creep stresses of the cylinder are investigated. A numerical solution using finite element method is also presented and good agreement was found. Although previous publications presented analytical solutions for creep analysis of thick-walled cylindrical pressure vessels under uniform pressure, to the best of the authors’ knowledge, so far, no analytical solution has been provided for time-dependent creep analysis of FG cylinder under non-uniform internal pressure. The results of this study are applicable for designing optimum FG thick-walled cylinder.

A Single Technically Consistent Design Formula for the Thickness of Cylindrical Sections Under Internal Pressure

2005 ◽  
Author(s):  
John D. Fishburn
Keyword(s):  
Experimental Data ◽  
Internal Pressure ◽  
State Of The Art ◽  
Original Data ◽  
Pressure Vessels ◽  
Time Dependent ◽  
Design Codes ◽  
Recent Developments ◽  
Current Design ◽  
Single Formula

Within the current design codes for boilers, piping and pressure vessels, there are many different equations for the thickness of a cylindrical section under internal pressure. A reassessment of these various formulations, using the original data, is described together with more recent developments in the state of the art. A single formula, which can be demonstrated to retain the same design margin in both the time-dependent and time-independent regimes, is shown to give the best correlation with the experimental data and is proposed for consideration for inclusion in the design codes.

Design of Radial Nozzles in Cylindrical Shells for Internal Pressure

1980 ◽  
Vol 102 (1) ◽  
pp. 70-78 ◽  
Author(s):  
W. L. McBride ◽  
W. S. Jacobs
Keyword(s):  
Internal Pressure ◽  
Elastic Stress ◽  
Design Method ◽  
Pressure Vessels ◽  
Strain Gages ◽  
Allowable Stress ◽  
Working Pressure ◽  
Division 1 ◽  
Section Viii ◽  
Empirical Design

A design method is presented that allows a designer to predict the maximum allowable working pressure of an opening reinforcement using an allowable stress basis. Primary application of the method is directed toward large openings as defined by ASME Section VIII, Division 1, paragraph UA-7. Recent hydrotests conducted on several production pressure vessels have demonstrated that existing paragraph UA-7 area replacement rules are inadequate in certain d/D and D/T ranges. The inadequate designs were initially indicated by leakage at a flange located close to the nozzle shell intersection. Later, another vessel hydrotest was terminated because of distortion and high readings from strain gages located at the nozzle-to-shell intersection. The proposed empirical design method produces nozzle reinforcements that should remain in the elastic stress range for internal pressure up to the Code-required hydrotest.

Probabilistic evaluation of detection capability of eddy current testing to inspect pitting on a stainless steel clad using multiple signal features

2020 ◽  
Vol 64 (1-4) ◽  
pp. 47-55
Author(s):  
Takuma Tomizawa ◽  
Haicheng Song ◽  
Noritaka Yusa
Keyword(s):  
Stainless Steel ◽  
Eddy Current ◽  
Pressure Vessels ◽  
Eddy Current Testing ◽  
Probability Of Detection ◽  
Current Testing ◽  
Multiple Signal ◽  
Signal Features ◽  
Inner Surface ◽  
Drill Holes

This study proposes a probability of detection (POD) model to quantitatively evaluate the capability of eddy current testing to detect flaws on the inner surface of pressure vessels cladded by stainless steel and in the presence of high noise level. Welded plate samples with drill holes were prepared to simulate corrosion that typically appears on the inner surface of large-scale pressure vessels. The signals generated by the drill holes and the noise caused by the weld were examined using eddy current testing. A hit/miss-based POD model with multiple flaw parameters and multiple signal features was proposed to analyze the measured signals. It is shown that the proposed model is able to more reasonably characterize the detectability of eddy current signals compared to conventional models that consider a single signal feature.

ALUCHROM YHf

Alloy Digest ◽  
2004 ◽  
Vol 53 (1) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
North America ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Pressure Vessels ◽  
Temperature Performance ◽  
Oxidation Resistant

Abstract Aluchrom YHf is an oxidation resistant ferritic stainless steel alloyed with aluminum. The alloy is approved in North America and Europe for pressure vessels to 899 deg C (1650 deg F). This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-899. Producer or source: ThyssenKrupp VDM GmbH.

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