How to Install Ellipsoidal Head Calculation Software

1. Download File EllipHeadCalc.rar in http://www.ziddu.com/download/6044170/EllipHeadCalc.rar.html
Download File actskin4.rar in http://www.ziddu.com/download/6338933/actskin4.rar.html
Download File VB5DB.rar in http://www.ziddu.com/download/6338956/VB5DB.rar.html


2. Extract All file, example to d:\software\Pressure Vessel



Use Password : dede

3. Copy actskin4.ocx and vb5db.dll to c:/windows/system32
4. Run Program Double clic eliphead.exe
5. Enter password : dede



6. Enjoy Program

Note: Program Maybe not maximum functional, because i not make installation setup, when I make installation setup, file is too big.

ELLIPSOIDAL HEAD THICKNESS CALCULATION ( PREVEDAS)

Last week I was posting about calculation of shell thickness in pressure vessel, now I sharing ellipsoidal head thickness calculation base on ASME VIII div 1.



The required thickness of a dished head of semi ellipsoidal form, in which half the, minor axis (inside depth of the head minus the skirt) equals one-fourth of the inside diameter of the head skirt, shall be determined by



Where;



t = minimum required thickness of head after forming, in. (mm)
P = internal design pressure (see UG-21), psi (kPa)
D = inside diameter of the head skirt; or inside length of the major axis of an ellipsoidal head; or inside diameter of a conical head at the point under consideration, measured perpendicular to the longitudinal axis, in. (mm)
S = maximum allowable stress value in tension as given in the tables referenced in UG-23, psi (kPa)
E = lowest efficiency of any joint in the head; for hemispherical heads this includes head-to-shell joint; for welded vessels, use the efficiency specified in UW-12

Same as previously, I also make the computer program (software) to make easier for us in conducting calculation. Please see picture bellow.



This program also can show and print the report of calculation, please see sample report bellow.



Please download sample program in http://www.ziddu.com/download/6044170/EllipHeadCalc.rar.html

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SHELL THICKNESS CALCULATION

This calculation base on ASME section VIII Div.1

UG-27 THICKNESS OF SHELLS UNDER INTERNAL PRESSURE

(a) The thickness of shells under internal pressure shall be not less than that computed by the following
formulas. In addition, provision shall be made for any of the other loadings listed in UG-22, when such
loadings are expected. (See UG-16.)

(b) The symbols defined below are used in the formulas of this paragraph.
t = minimum required thickness of shell, in.
P = internal design pressure (see UG-21), psi
R = inside radius of the shell course under consideration in.
S = maximum allowable stress value, psi
E = joint efficiency for, or the efficiency of, appropriate joint in cylindrical or spherical shells, or
the efficiency of ligaments between openings, whichever is less.
For welded vessels, use the efficiency specified in UW-12.
For ligaments between openings, use the efficiency calculated by the rules given in UG-53.

(c) Cylindrical Shells. The minimum thickness or maximum allowable working pressure of cylindrical
shells shall be the greater thickness or lesser pressure as given by (1) or (2) below.
(1) Circumferential Stress (Longitudinal Joints).
When the thickness does not exceed one-half of the inside radius, or P does not exceed 0.385SE, the
following formulas shall apply:



(2) Longitudinal Stress (Circumferential Joints).16
When the thickness does not exceed one-half of the inside radius, or P does not exceed 1.25SE, the following formulas shall apply:



(d) Spherical Shells. When the thickness of the shell of a wholly spherical vessel does not exceed 0.356R,
or P does not exceed 0.665SE, the following formulas shall apply:



(e) When necessary, vessels shall be provided with stiffeners or other additional means of support to prevent overstress or large distortions under the external loadings listed in UG-22 other than pressure and temperature.

(f) A stayed jacket shell that extends completely around a cylindrical or spherical vessel shall also meet
the requirements of UG-47(c).

(g) Any reduction in thickness within a shell course or spherical shell shall be in accordance with UW-9.

I have been made some computer program to calculate minimum required thickness of cylindrical shell and Maximum Allowable Working Pressure (MAWP). Please see picture bellow.




This program is simple, you only input value on design data and then click calculate button, and the result in design calculation.
This program also can show and print the report of calculation, please see sample report bellow.





http://www.ziddu.com/download/5831004/PressureVesselShellCalculation.exe.html

Local Stresses in Pressure Vessels Due to Internal Pressure and Nozzle Loadings

By Ray Chao

The subject of local stresses in the vicinity of nozzles in pressure vessels has been investigated for more than forty years. Indeed, the nozzle-to-shell intersection has been one of the most researched areas of pressure vessels. As a result of this effort, several practical approaches to this problem have evolved which enable the vessel designers to check the adequacy of nozzle designs in pressure vessels. However, very little direction has been given on the calculations on local stresses due to the combined internal pressure and external nozzle loadings. This article will address this problem and provide guidance to the vessel designers in the correct application of the available simplified calculation methods for local stresses in pressure vessels.

One of the most widely used methods has been that detailed in the Welding Research Council (WRC) Bulletin 107 published in 1965. In 1989, WRC Bulletin 297 was published as a supplement to WRC Bulletin 107. Together, they provide a simplified approach to the calculations of local stresses due to the combined internal pressure and external nozzle loadings. This article will address this problem and provide guidance to the vessel designers in the correct application of the available simplified calculation methods for local stresses in pressure vessels.

Local stresses, however, also occur in the vicinity of nozzles due to internal pressure. Therefore, a complete evaluation would require that these stresses be accounted for, in addition to those due to external loadings. The calculations of the total local stresses due to the combined internal pressure and external loadings have not, in general, been done correctly. It appears that the following two approaches have often been taken but neither of these will give correct answers.

* The nozzle is reinforced in accordance with the ASME Code, Section VIII, Division 1 based on the internal design pressure. This has been taken as being sufficient to nullify the effect of nozzle opening and only the general membrane stresses in the vessel due to internal pressure are calculated and superimposed to those due to external loadings.
* The internal pressure in the nozzle is converted into a radial outward thrust force on the nozzle and this is combined with the other nozzle loadings which are then used in the calculations of local stresses in the vicinity of the nozzle using the WRC Bulletins 107 and 297.

The local stress calculations using WRC Bulletins 107 and 297 have been incorporated in several commercially available engineering computer programs. In fact, the two approaches described above to account for the effect of internal pressure have been incorporated into at least one of such programs. The use of these approaches will give grossly incorrect results.

The first approach ignores the local stresses due to internal pressure which will result in an underestimate of the total local stresses due to the combined internal pressure and nozzle loadings. The second approach, on the other hand, will result in an overestimate of the local stresses, as has been shown in an earlier article (FEM Analysis of a Large Nozzle-to-Cylinder Shell Junction, by Doug Stelling, Carmagen Report, October 1996). It should be noted that WRC Bulletins 107 and 297 are intended for external nozzle loadings only and should not be used for pressure thrust loads on nozzles.

In 1991, WRC Bulletin 368 was published to fulfill the need for the determination of local stresses at nozzles due to internal pressure. The design formulas presented in this bulletin were based on the results of a parametric study performed using the computer program FAST2. Using these formulas, the maximum membrane and surface stresses in the vessel shell and nozzle at the nozzle-to-shell intersection may be computed. The resulting stresses due to internal pressure may then be combined with those due to external nozzle loadings by superposition.

A final evaluation of the acceptability of the design requires that the computed stresses be compared to an allowable stress basis. ASME Code, Section VIII, Division 1 provides no guidance on the evaluation of local stresses in pressure vessels. In fact, it does not specifically require a detailed stress analysis to evaluate the higher, localized stresses that are known to exist, but instead allow for these by lower basic allowable stresses and a set of design rules. Yet, it does require that loadings such as those acting on the nozzles be considered in designing a vessel. Therefore, local stresses due to nozzle loadings are often calculated and evaluated using the guidelines given in Division 2.

A calculated value of stress means little until it is associated with its location and distribution in the structure and with the type of loading which produces it. Different types of stress have different degrees of significance and must, therefore, be assigned different allowable values. Division 2 provides detailed guidance on the classification of stresses and also provides associated allowable stress limits. However, further discussions on the calculated local stresses due to internal pressure and external nozzle loadings using the WRC bulletins are warranted and this will be covered in a future article.

http://www.carmagen.com/news/engineering_articles/news30.htm

Ellipsoidal head

There are 2 types of Ellipsoidal heads:

* Ellipsoidal head 2:1 acc. ASME VIII Div. 1 and 2
* Ellipsoidal head 1,9:1 acc. NF E 81-103

The dimension values 2:1 respectively 1,9:1 are the ratio between the small and the large axis of the ellipses. Both head shapes correspond nearly to the geometry of the Semi-ellipsoidal head acc. DIN 28013. The dimensions can be approximately calculated as follows:



http://www.koenig-co.de/english/pages/boeden/bod_eb.htm

Thin Wall Pressure Vessels

Thin wall pressure vessels are in fairly common use. We would like to consider two specific types. Cylindrical pressure vessels, and spherical pressure vessels. By thin wall pressure vessel we will mean a container whose wall thickness is less than 1/10 of the radius of the container. Under this condition, the stress in the wall may be considered uniform.


We first look at a cylindrical pressure vessel shown in Diagram 1, where we have cut a cross section of the vessel, and have shown the forces due to the internal pressure, and the balancing forces due to the longitudinal stress which develops in the vessel walls. (There is also a transverse or circumferential stress which develops, and which we will consider next.)





The longitudinal stress may be found by equating the force due to internal gas/fluid pressure with the force due to the longitudinal stress as follows:
P(A) = (A'); or P(3.1416 * R2) = (2 * 3.1416 * R * t), then canceling terms and solving for the longitudinal stress, we have:
= P R / 2 t ; where
P = internal pressure in cylinder; R = radius of cylinder, t = wall thickness

To determine the relationship for the transverse stress, often called the hoop stress, we use the same approach, but first cut the cylinder lengthwise as shown in Diagram 2.



We once again equate the force on the cylinder section wall due to the internal pressure with the resistive force which develops in walls and may be expressed in terms of the hoop stress, . The effective area the internal pressure acts on may be consider to be the flat cross section given by (2*R*L). So we may write:
P(A) = (A'); or P(2*R*L) = (2*t*L), then canceling terms and solving for the hoop stress, we have:
= P R / t ; where
P = internal pressure in cylinder; R = radius of cylinder, t = wall thickness
We note that the hoop stress is twice the value of the longitudinal stress, and is normally the limiting factor. The vessel does not have to be a perfect cylinder. In any thin wall pressure vessel in which the pressure is uniform and which has a cylindrical section, the stress in the cylindrical section is given by the relationships above.

Example A: A thin wall pressure vessel is shown in Diagram 3. It's cylindrical section has a radius of 2 feet, and a wall thickness of the 1". The internal pressure is 500 lb/in2. Determine the longitudinal and hoop stresses in the cylindrical region.





Solution:We apply the relationships developed for stress in cylindrical vessels.
= P R / 2 t = 500 lb/in2 * 24"/2 * 1" = 6000 lb/in2.
= P R / t = 500 lb/in2 * 24"/ 1" = 12, 000 lb/in2.



Next we consider the stress in thin wall spherical pressure vessels. Using the approach as in cylindrical vessels, in Diagram 4 we have shown a half section of a spherical vessel. If we once again equal the force due to the internal pressure with the resistive force expressed in term of the stress, we have:

P(A) = (A'); or P(3.1416 * R2) = (2 * 3.1416 * R * t), then canceling terms and solving for the stress, we have:



= P R / 2 t ; where
P = internal pressure in sphere; R = radius of sphere, t = wall thickness

Note that we have not called this a longitudinal or hoop stress. We do not do so since the symmetry of the sphere means that the stress in equal in what we could consider a longitudinal and/or transverse direction.

Example B. In Example A, above, if the radius of the spherical section of the container is also 2 feet, determine the stress in the spherical region.

Solution: We apply our spherical relationship:
= P R / 2 t = 500 lb/in2 * 24"/2 * 1" = 6000 lb/in2.
Thus in the container in Example A, the limiting (maximum) stress occurs in the in the cylindrical region and has a value of 12,000 lb/in2.


http://physics.uwstout.edu/statstr/statics/Columns/cols65.htm

P&ID

P&ID is a detailed graphical representation of a process including the hardware and software (e.g., piping, equipment, instrumentation) necessary to design, construct and operate the facility. Common synonyms for P&IDs include EFDs (Engineering Flow Diagrams), UFDs (Utility Flow Diagrams) and MFDs (Mechanical Flow Diagrams).

Stress Definition

Stress Definition

Stress is internal force exerted by either of two adjacent parts of a body upon the other across an imagined plane of separation. When the forces all parallel to the plane, the stress is called shear stress, when the forces are normal to the plane the stress is called normal stress, when the normal stress is directed toward the part on which it acts it is called compressive stress, when it is directed away from the part on which it acts is called tensile stress.

Mechanical Calculation

Mechanical Engineering is an engineering discipline that involves the application of principles of physics and chemistry for analysis, design, manufacturing, and maintenance of various systems. Mechanical engineering is one of the oldest and broadest engineering disciplines.

It requires a solid understanding of core concepts including mechanics, kinematics, thermodynamics, fluid mechanics, and energy. Mechanical engineers use the core principles as well as other knowledge in the field to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, motor vehicles, aircraft, watercraft, robotics, medical devices and more.

http://en.wikipedia.org/wiki/Mechanical_engineering