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DESIGN AND ANALYSIS OF PRESSURE VESSEL

BY

JIMIT VYAS AND MAHAVIR SOLANKI

GUIDED BY : MR BHAVESH PATEL

U V PATEL COLLEGE OF ENGINEERING 

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  ACKNOWLEDGEMENT
Certainly, help and encouragement from others are always appreciated, but in different times, such magnanimity is valued even more. This said, this Dissertation would never have been completed without the generous help and support that I received from numerous people along the way.

I wish to express my deepest thanks and gratitude to my elite guide Mr Bhavesh P Patel, Mechanical Engineering Dept., U.V. Patel College of Engg., Mehsana, for his invaluable guidance and advice, without that the Dissertation would not have appear in present shape. He also motivated me at every moment during entire dissertation.

I also hearty thankful and express deep sense of gratitude to Mr. Bhavesh Prajapati, senior manager at GMM Pflauder, for giving opportunity to undertake a dissertation in the industry and furnishing the details and help. Special thanks to Mr. Ankit Prajapati, Design Engineer, at GMM Pflauder, for his keen interest and guidance in carrying out the work. I wish to thank the principal Dr. J. L. Juneja and all the staff members of Mechatronics & Mechanical Dept., U. V. Patel College of Engg., especially to , Prof. J. M. Prajapati, Prof. J. P. Patel, Prof. V. B. Patel, for their co-operation, guidance and support during the work.

Jimit Vyas & Mahavir Solanki

U V PATEL COLLEGE OF ENGINEERING 

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ASTRACT
The significance of the title of the project comes to front with designing structure of the pressure vessel for static loading and its assessment by Ansys , is basically a project concerned with design of different pressure vessel elements such as shell, Dish end ,operating manhole ,support leg based on standards and codes ; and evolution of shell and dish end analysed by means of ansys .The key feature included in the project is to check the behaviour of pressure vessel in case of fluctuating load .The [procedural step includes various aspects such as selecting the material based on ASME codes ,and then designing on the standards procedures with referring standard manuals based on ASME .Further we have included the different manufacturing methods practice by the industries and different aspects of it . And step by step approaches to the NTD method practice by the industries followed with standards and also included within the report work. This will be making a clear picture f this method among the reader . conclusively, this modus operandi of design based on technical standard and codes ., can be employed on practical design of pressure vessel as per required by the industry or the problem statement given associated to the field of pressure vessel.

U V PATEL COLLEGE OF ENGINEERING 

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the shape of the pressure vessel (i.. t. r. Both types of analysis are discussed here. cylinder or tanks) are used to store fluids under pressure. The most common method is based on a simple mechanics approach and is applicable to “thin wall” pressure vessels which by definition have a ratio of inner radius. The normal stresses resulting from this pressure are functions of the radius of the element under consideration. boilers and tanks) are commonly used in industry to carry both liquids and gases under pressure.. pipes.e. Cylindrical or spherical pressure vessels (e. The fluid being stored may undergo a change of state inside the pressure vessel as in case of steam boilers or it may combine with other reagents as in a chemical plant. from all directions. The pressure vessels are designed with great care because rupture of pressure vessels means an explosion which may cause loss of life and property. When the pressure vessel is exposed to this pressure. The material of pressure vessels may be brittle such that cast iron or ductile such as mild steel. and hence stresses. U V PATEL COLLEGE OF ENGINEERING  Page 4  . of r/t≥10. to wall thickness.e. the thin wall pressure vessel can be used. open ended cylinder. The second method is based on elasticity solution and is always applicable regardless of the r/t ratio and can be referred to as the solution for “thick wall” pressure vessels. gun barrels. although for most engineering applications. Two types of analysis are commonly applied to pressure vessels.g. hydraulic cylinders.  INTRODUTION: The pressure vessels (i. the material comprising the vessel is subjected to pressure loading. closed end cylinder. or sphere) as well as the applied pressure.

  Classification of Pressure Vessels Unfired Cylindrical Pressure Vessels (Classification Based on IS 2825-1969) a) Class 1 : Vessels that are to contain lethal or toxic substances. class3 vessels are not recommended for services at temperatutre below 0c. b) Class 2: vessels which do not fall in the scope of clas1 and class 3 are to be termed as class2 vessels. and they are built for working pressures at temperatures not exceeding 250 c and unfired . U V PATEL COLLEGE OF ENGINEERING  Page 5  . c) class 3: there are vessels for relatively light duties having plate thickness not in excess of 16 mm. The maximum thickness of shell is limited to 38 mm. Vessels designed for the operation below -20 C and Vessels intended for any other operation not stipulated in the code.

d) Category d: welded joints connecting communicating chambers or nozzles to main sheels . communicating chambers. nozzles and transitions in diameter including joints between the transtations and a cylinder at either the large of small end. circumferential welded joints connecting from heads to main shells to nozzles and to communicating chambers. to formed heads . (Refer fig. tubes sheets and flat heads to main shells . to nozzles or to communicating chambers and any welded joints connecting one side plate to another side plate of a flat sided vessel. U V PATEL COLLEGE OF ENGINEERING  Page 6  .to heads and to flat sided vessels and those joints connecting nozzles to communicating chambers. communicating chambers . but not the type of joint. IS-2825 specifies 4 categories of welds.nozzles and any welded joints within a formed or flat head. c) Category c: welded joints connecting flanges. b) Category B: circumferential welded joints with in the main shell.  Categories Of Welded Joints The term categories specifies the location of the joint in a vessels.) a) category A: longitudinal welded joints within the main sheet. These categories are intended for specifying the special requirements regarding the joint type and degree of inspection.

Primary general stress are divided into membrane and U V PATEL COLLEGE OF ENGINEERING  Page 7  . Qm Secondary bending stress Qb Peak stress. Primary stress are generally due to internal or external pressure or produced by sustained external forces and moments.  STRESS Types of Stresses Tensile Compressive Bending Axial Membrane Principal Tangential Strain induced Longitudinal Normal Shear Bearing Discontinuity Tensile Thermal Load induced Circumferential Radial Classes of stress Primary Stress General: Primary general membrane stress Pm Primary general bending stress Pb Primary local stress. PL Secondary stress: Secondary membrane stress. F Definition and Examples PRIMARY GENERAL STRESS: These stress act over a full cross section of the vessel.

Bending stress in a shallow conical head. LOCAL PRIMARY MEMBRANE STESS. Bending stress in the ligaments of closely spaced openings. Primary general bending stress.  bending stresses. PL Pm+ membrane stress at local discontinuities: Head-shell juncture Cone-cylinder juncture Nozzle-shell juncture Shell-flange juncture Head-skirt juncture Shell-stiffening ring juncture Pm+ membrane stresses from local sustained loads: Support legs Nozzle loads Beam supports Major attachments SECONDARY STRESS Secondary membrane stress Qm Axial stress at the juncture of a flange and the hub of the flange Thermal stresses. Compressive and tensile axial stresses due to wind. Calculated value of a primary bending stress may be allowed to go higher than that of a primary membrane stress. Pm Circumferential and longitudinal stress due to pressure. Pb Bending stress in the centre of a flat head or crown of a dished head. Axial compression due to weight. U V PATEL COLLEGE OF ENGINEERING  Page 8  . Longitudinal stress due to the bending of the horizontal vessel over the saddles. Membrane stress in the nozzle wall within the area of reinforcement due to pressure or external loads. Membrane stress in the centre of the flat head. Primary general membrane stress.

etc. (relenting loadings only). the stresses from the inward radial load could be either a primary local stress or secondary stress. Membrane stress due to local relenting loads. Loadings may be applied over a large portion (general area) of the vessel or over a local area of the vessel. Secondary bending stress. Thermal stress in a wall caused by a sudden change in the surface temperature. Peak Stress F Stress at the corner of discontinuity. Qb Bending stress at the gross structural discontinuity: nozzle. The stresses applied more or less continuously and uniformly across an entire section of the vessel are primary stresses.  Membrane stress in the knuckle area of the head. U V PATEL COLLEGE OF ENGINEERING  Page 9  . It is primary local stress if it is produced from an unrelenting load or a secondary stress if produced by a relenting load. The nonuniform portion of the stress distribution in a thick-walled vessels due to internal pressure. General and local loads can produce membrane and bending stresses. The stress variation of the radial stress due to internal pressure in thick-walled vessels. O the other hand. The stresses due to pressure and wind are primary membrane stresses. LOADINGS Loadings or forces are the “causes” of stress in pressure vessels. Stress due to notch effect. These stresses are additive and define the overall state of stress in the vessel or component. lugs.. (stress concentration). Discontinuity stresses at stiffening or support ring. Thermal stresses in cladding or weld overlay.

Torsional load. U V PATEL COLLEGE OF ENGINEERING  Page 10  . Moment loads—Due to wind. f.  If it is a primary stress.e.5 SE PL=Pm+Qm< 1. seismic. hydrotest.. Basically each combination of stresses ( stress categories will have different allowables. the load will relax once slight deformation occurs. Thermal loads—Hot box design of skirt-head attachment. platforms. a. Compressive/tensile loads—Due to dead weight. i. Thermal load. if it is a secondary stress. transportation.. Primary stress: Pm < SE Primary membrane local (PL): PL=Pm+ PL <1. Shear load—Longitudinal or circumferential. piping and vessel contents. erection. mixers. Radial load—Inward or Outward. installed equipment. Local loads—Due to reactions from supports.5SE Primary membrane + secondary (Q): Pm+Q< 3SE Loading can be outlined as follows: Categories of loadings General loads—Applied more or less continuously across a vessel section. Pressure loads—Internal or external pressure (design. attached equipment. c. i. Tangential load. d. e. b. attached Piping. ladders. Moment load—Longitudinal or circumferential. platforms. etc. internal. operating. and hydrostatic head of liquid).e. the stress will be redistributed.

defects in material. shut down FAILURE IN PRESSURE VESSELS Categories of Failures: Material--Improper Selection of materials. Internal/external pressure. f. continuous. Wind Loads Types of Loadings 1) Non-steady loads. Design—Incorrect design data. c. improper or insufficient fabrication procedures including welding. inadequate shop testing. heat treatment or forming methods. g. emergency Thermal Loads Startup. inaccurate or incorrect design methods. Thermal loads. Loadings to and from vessel supports. Dead weight.  Types of Loadings 1) Steady loads—Long-term duration. Loading due to attached piping and equipment. U V PATEL COLLEGE OF ENGINEERING  Page 11  . d.Short-term duration. Shop and field hydro-test Earthquake Erection Transportation Upset. e. a. b. Fabrication – Poor quality control. Vessel contents. Variable.

Division 2. vessel geometry. Brittle fractures have occurred in vessels made of low carbon steel in the 40-50 F range during hydrotest where minor flaws exist. i. and fabrication methods are as follows: Lethal Fatigue (cyclic) Brittle (low temperature) High Temperature High shock or vibration Vessel contents Hydrogen Ammonia Compressed air Caustic Chlorides TYPES OF FAILURES Elastic deformation—Elastic instability or elastic buckling. Stress rupture—Creep deformation as a result of fatigue or cyclic loading. and stiffness as well as properties of materials are protecting against buckling. whereas fatigue is a cyclic-dependent phenomenon o TYPES OF FAILURES o Plastic instability—Incremental collapse. Brittle fracture—Can occur at low or intermediate temperature.. are intended to prevent excessive plastic deformation and incremental collapse. incremental collapse is cyclic strain accumulation or cumulative cyclic deformation. Cumulative damage leads to instability of vessel by plastic deformation. U V PATEL COLLEGE OF ENGINEERING  Page 12  . Creep is a time-dependent phenomenon.e. design details. Some types of services which requires special attention both for selection of materials. progressive fracture.  Service—Change of service condition by the user. inexperienced operations or maintenance personnel. Excessive plastic deformation—The primary and secondary stress limits as outlined in ASME Section VIII. upset conditions.

SPECIAL PROBLEMS Thick Walled Pressure Vessels Mono-bloc. Material selection and fatigue properties are the major considerations. Corrosion can reduce fatigue life by pitting the surface and propagating cracks.” Multilayer auto-frettage—Begins with a core about ½ in.Solid vessel wall. This creates compressive stress in the core. Multi-wall—Begins with a core about ½ in. Materials selection is critical in these services. Multilayer—Begins with a core about ½ in. The process of compressing layers is called auto-frettage from the French word meaning “selfhooping. Bands or forged rings are slipped outside and then the core is expanded hydraulically. to 2 in. o Corrosion fatigue—Occurs when corrosive and fatigue effects occur simultaneously.  o o High Strain—Low cyclic fatigue is strain-governed and occurs mainly in lowerstrength/high-ductile materials. thick. The elastic deformation residual in U V PATEL COLLEGE OF ENGINEERING  Page 13  . Outer layers about the same thickness are successive “ shrunk fit” over the core. Stress corrosion—It is well know that chlorides cause stress corrosion cracking in stainless steels. likewise caustic service can cause stress corrosion cracking in carbon steel. which is relaxed during pressurization. The core is stressed into plastic range but below ultimate strength. thick. The outer rings are maintained at a margin below yield strength. Each layer is vented (except the core) and welded individually with no overlapping welds. thick and successive layers are applied.

Discontinuity stresses are “ secondary stresses” and are self-limiting. Wire wrapped vessels: Begin with inner core of thickness less than required for pressure. material. Vessels 5 to 6 ft in diameter for pressure up to 5000psi have been made in this manner. they must deflect and rotate together. since they are connected in a continuous structure. Coil wrapped vessels: Begin with a core that is subsequently wrapped or coiled with a thin steel sheet until the desired thickness is obtained. Thermal stresses will not cause failure by rupture. U V PATEL COLLEGE OF ENGINEERING  Page 14  . Discontinuity stresses do become an important factor in fatigue design where cyclic loading is a consideration. which is relaxed during pressurization. THERMAL STRESS Whenever the expansion or contraction that would occur normally as a result of heating or cooling an object is prevented. However. The stress is always caused by some form of mechanical restrain. Thermal stresses are “secondary stresses” because they are self-limiting. one attaching the sheet to the core and the final closures weld. diameter and change in directions would all have different displacements if allowed to expand freely. the vessel is in cyclic service. cause failure due to excessive deformations. Only two longitudinal welds are used.  the outer bands induces compressive stress in the core. Core is wrapped with steel cables in tension until the desired autofrettage is achieved. thermal stresses are developed. DISCONTINUITY STRESSES Vessel sections of different thickness. FATIGUE ANALYSIS When a vessel is subject to repeated loading that could cause failure by the development of a progressive fracture. They can however. Fatigue analysis can also be a result of thermal vibrations as well as other loadings. The stresses in the respective parts at or near the juncture are called discontinuity stresses.

No reinforcement other than that inherent in the construction is required for nozzles. 3-in. b. and less. misalignment. Normal reinforcement methods apply to Page 15  U V PATEL COLLEGE OF ENGINEERING  . pipe size and smaller in vessel walls 3/8 in. defects in construction. NOZZLE REINFORCEMENT Fig : nozzle reinforcement Limits.  In fatigue service the localized stresses at abrupt changes in section. a. 2-in. such as at a head junction or nozzle opening. and thermal gradients are the significant stresses. pipe size and smaller in vessel walls greater than 3/8 in.

Vessels greater than 60-in. re-pads can also be put inside providing they do not interfere with the vessel’s operation. 4. Openings < ½ head diameter. 8. Strength It is advisable but not mandatory for reinforcing pad material to be the same as the vessel material.in a. reinforcement shall be in accordance with para. Openings in flat heads: Reinforcements for the openings in the flats heads and blind flanges shall be as follows a. Thickness It is recommended that pad be not less then 75% nor more than 150% of the part to which they are attached. Forming: Reinforcing pads should be formed as closely to the contour of the vessel as possible. either in the pad or in the nozzle neck. 5.414 b.  Vessels 60-in. no additional credit may be taken for the higher strength. U V PATEL COLLEGE OF ENGINEERING  Page 16  . 2. diameter-1/3 the vessel diameter but not to exceed 40.area to be replaced equals 0.75 Increasing head thickness by 1. While normally put on the outside of the vessel. it is recommended that re-pads be atleast 2in wide.5(tr). Openings>1/2 head diameter –shall be designed as a bolted flange connection. 1b. Openings in torispherical heads. diameter and less-1/2 the vessel diameter but not to exceed 20 in. 1-7 of ASME Code. Width While no minimum is stated. or thickness of head or flange may be increased by: Doubling C value Using C=0. 3. a. If a higher strength material is used. 9.

is thickness required for external pressure 16. 14. the required thickness of head for reinforcement purpose shall be computed using M=1 10. does not allow a welded joint to have two different weld joint efficiencies 13. Reinforcement required for openings subject to external pressure only or when longitudinal compression governs shall only be 50 % of that required for internal pressure and tr.  When a nozzle openings and all its reinforcement fall within the dished portion. division 1. Openings near seams Small nozzles ( for which the code does not require. a. Openings that have been reinforcement may located in a welded joint. ASME code. 11. External pressures. Openings in elliptical heads When a nozzle openings and all its reinforcement fall within 0. pads should not cover weld seams. the required thickness of the head for reinforcement purpose shall be equal to the thickness required for a seamless sphere of radius K(D). the seam should be ground flush before attaching the pad. Ligaments When there is a series of closely spaced openings in a vessel shell and it is impractical to reinforce each opening. When unavoidable.8 D of an elliptical head. the construction efficiency of the ligaments between the holes is acceptable. to the edge of a main seam. provided the U V PATEL COLLEGE OF ENGINEERING  Page 17  . Re-pads over seams If at all possible. 17. Openings through seams. 15. the reinforcement to be checked) shall not be located closer than ½ in. General Reinforcement should be calculated in the corroded condition assuming maximum tolerance (minimum t) 12. Multiple openings: is acceptable.

  a.5 for circumferential. 3. b. A correction factor f may be used for “ integrally reinforced” nozzle to compensate for differences in stress from longitudinal to circumferential axis of the vessel. For two openings closer than 2 times the average diameters and where limits of reinforcement overlap. 1. c. Must have a combined area equal to the sum of the two areas 2. U V PATEL COLLEGE OF ENGINEERING  Page 18  . The area of reinforcement between the two nozzle shall be atleast 50% of the area Multiple openings may be reinforced s an opening equal in diameter to that of a Plane of reinforcement. When more than two openings are to be provided with combined reinforcement: The minimum distance between the two centers is 1 1/3 the average diameters. Any overlap area shall be proportional between the two openings by the ratio of the diameters. 2. No portion of the cross-section shall apply to more than one openings. Value of f vary from 1. the area between the openings shall meet the following 1. circle circumscribing the multiple openings. 18. required for the two openings.0 for the longitudinal axis to 0. When more than two openings are to be provided with combined reinforcement: 17 b.

  CHAPTER 2 ENGINEERING GUIDELINES FOR DESIGN OF PRESSURE VESSELS U V PATEL COLLEGE OF ENGINEERING  Page 19  .

Bins.2 For Pressure vessels (Selectively for high pressure / high thickness / critical service) ASME SEC.Vessels . Hoppers . VIII DIV.Reactors .Steel silos.Columns .Steel Flare Stacks 2.Storage Tanks . Page 20  For Pressure vessels U V PATEL COLLEGE OF ENGINEERING  . VIII DIV.1 / IS: 2825 ASME SEC. VIII DIV.3 API 650 / IS: 803 API 620 For Storage Spheres For Pressure vessels (Selectively for high pressure) For Storage Tanks. VIII DIV.0 CODES AND STANDARDS The following codes and standards shall be followed unless otherwise specified: ASME SEC. For Low Pressure Storage Tanks.Spheres .2 ASME SEC.  Engineering Design Guidelines For Pressure Vessels 1.0 SCOPE This specification covers the design basis for following equipment: .

IX WRC BULLETIN# 107.` Welded Aluminium Alloy Storage Tanks. steam storage catch water vessels.1 Cryogenic Storage Tanks (Double Wall) For workmanship of Vessels not categorized under any other code. 3.1 ASME SEC. For material specification For material specification (Tanks) For wind load consideration For seismic design consideration For welding.  API 620 / BS 7777 ASME SEC. condensate flash drums and similar vessels IS: 9178 / DIN 1055 BS: 4994 / ASME SEC X ASME: B 96. and applicable standards/ Specifications.II ASTM / IS IS: 875 / SITE DATA IS: 1893 / SITE DATA ASME SEC. ISO R831/ IBR For Steam producing. 297 / PD 5500 For Local load / stress analysis For Silos Hoppers and Bins FRP vessels / tanks.0 DESIGN CRITERIA Equipment shall be designed in compliance with the latest design code requirements. VIIIDIV. U V PATEL COLLEGE OF ENGINEERING  Page 21  .

5 + Corrosion Allowance All dimension are in mm.0mm). if any. if any shall be added to minimum thickness. but not less than that calculated as per following: FOR DIAMETERS LESS THAN 2400mm Wall thickness = Dia/1000 +1. e) For stainless steel and high alloy columns / towers -5mm.0mm.5 Corrosion Allowance. Corrosion allowance. U V PATEL COLLEGE OF ENGINEERING  Page 22  . d) For carbon and low alloy steel columns / towers -8mm (including corrosion allowance not exceeding 3.6mm (Including corrosion allowance not exceeding 3. shall be added to minimum thickness. Wall thickness (mm) = Dia/1000 + 2.5 + Corrosion Allowance FOR DIAMETERS 2400mm AND ABOVE Wall thickness = Dia/1000 +2. c) Tangent to Tangent height (H) to Diameter (D) ratio (H/D) greater than 5 shall be considered as column and designed accordingly. but not less than that calculated as per following for diameter more than 1500mm.0 MINIMUM SHELL/HEAD THICKNESS Minimum thickness shall be as given below a) For carbon and low alloy steel vessels. b) For stainless steel vessel and high alloy vessels -3 mm.  4.

 
5.0 5.1 GENERAL CONSIDERATIONS Vessel sizing
All Columns All Clad/Lined Vessels All Other Vessels Tanks & Spheres Based on inside diameter Based on inside diameter Based on outside diameter Based on inside diameter

Vessels (Thickness>50mm) Based on inside diameter

5.2

Vessel End Closures :

- Unless otherwise specified Deep Torispherical Dished End or 2:1 Ellipsoidal Dished End as per IS - 4049 shall be used for pressure vessels. Seamless dished end shall be used for specific services whenever specified by process licensor. - Hemispherical Ends shall be considered when the thickness of shell exceeds 70mm. - Flat Covers may be used for atmospheric vessels - Pipe Caps may be used for vessels diameter < 600mm having no internals. - Flanged Covers shall be used for Vessels /Columns of Diameter < 900mm having internals. - All columns below 900mm shall be provided with intermediate body flanges. Numbers of Intermediate flanges shall be decided based on column height and type of internals

5.3

Pressure

Pressure for each vessel shall be specified in the following manner:

5.3.1 Operating Pressure
Maximum pressure likely to occur any time during the lifetime of the vessel

5.3.2 Design Pressure
a) When operating pressure is up to 70 Kg./cm2 g , Design pressure shall be equal to operating pressure plus 10% ( minimum 1Kg./cm2 g ). U V PATEL COLLEGE OF ENGINEERING  Page 23 

 
b) When operating pressure is over 70 Kg./cm2 g , Design pressure shall be equal to operating pressure plus 5% ( minimum 7 Kg./cm2g). c) Design pressure calculated above shall be at the top of vertical vessel or at the highest point of horizontal vessel. d) The design pressure at any lower point is to be determined by adding the maximum operating liquid head and any pressure gradient within the vessel. e) Vessels operating under vacuum / partial vacuum shall be designed for an external pressure of 1.055 Kg./cm2 g. f) Vessels shall be designed for steam out conditions if specified on process data sheet.

5.3.3 Test Pressure
a) Pressure Vessels shall be hydrostatically tested in the fabricators shop to 1.5 /1.3/ 1.25 (depending on design code) times the design pressure corrected for temperature. b) In addition, all vertical vessels / columns shall be designed so as to permit site testing of the vessel at a pressure of 1.5/ 1.3 / 1.25 (depending on design code) times the design pressure measured at the top with the vessel in the vertical position and completely filled with water. The design shall be based on fully corroded condition. c) Vessels open to atmosphere shall be tested by filling with water to the top. d) 1. Pressure Chambers of combination units that have been designed to operate independently shall be hydrostatically tested to code test pressure as separate vessels i.e. each chamber shall be tested without pressure in the adjacent chamber. 2. When pressure chambers of combination units have their common elements designed for maximum differential pressure the common elements shall be subjected to 1.5/ 1.3 times the differential pressure. 3. Coils shall be tested separately to code test pressure. e) Unless otherwise specified in applicable design code allowable stress during hydro test in tension shall not exceed 90% of yield point. f) Storage tanks shall be tested as per applicable code and specifications.

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5.4 Temperature

Temperature for each vessel shall be specified in the following manner:

5.4.1 Operating Temperature
Maximum / minimum temperature likely to occur any during the lifetime of vessel.

5.4.2 Design temperature
a) For vessels operating at 0C and over: Design temperature shall be equal to maximum operating temperature plus 15 0C. b) For Vessels operating below 0C: Design temperature shall be equal to lowest operating temperature. c) Minimum Design Metal Temperature (MDMT) shall be lower of minimum atmospheric temperature and minimum operating temperature.

5.5

Corrosion allowance :

Unless otherwise specified by Process Licensor, minimum corrosion allowance shall be considered as follows : - Carbon Steel, low alloy steel column, Vessels, Spheres : 1.5 mm - Clad / Lined vessel: Nil - Storage Tank, shell and bottom : 1.5 mm - Storage tank, Fixed roof / Floating Roof : Nil For alloy lined or clad vessels, no corrosion allowance is required on the base metal. The cladding or lining material (in no case less than 1.5 mm thickness) shall be considered for corrosion allowance. Cladding or lining thickness shall not be included in strength calculations. Corrosion allowance for flange faces of Girth / Body flanges shall be considered equal to that specified for vessel.

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Stored capacity shall be 90% of Nominal capacity.2 Sphere Stored capacity shall be 85% of nominal capacity.9 Manholes : a) Vessels and columns with diameter between 900 and 1000 mm shall be provided with 450 NB manhole. b) Drag coefficient for spherical vessel shall be 0. if required vessels and columns with diameter 1200mm and above may be provided with 600NB manhole. 5.8.8.  5.7 minimum. 5. 5.8 Capacity 5. b) For storage tanks minimum number of manholes (Size 500mm) shall be as follows: Tank Diameter Dia.1 Tank Capacity shall be specified as Nominal capacity and stored capacity Nominal capacity for fixed roof tanks be volume of cylindrical shell. < 8m Shell 1 Roof 1 Page 26  U V PATEL COLLEGE OF ENGINEERING  . Nominal capacity for floating roof tanks shall be volume of cylindrical shell minus free board volume. Vessels and columns with diameter greater than 1000mm shall be provided with 500 NB manhole.7 Earthquake Consideration : Earthquake load shall be calculated in accordance with IS : 1893 / site data if specially developed and available 5.6 minimum. However. a) Drag coefficient for cylindrical vessels shall be 0.6 Wind Consideration Wind load shall be calculated on the basis of IS : 875 / site data.

Tank Diameter 12 M < >12 M < 60M > 60M Type of Roof Double Deck Type Pontoon Type Double Deck Type 5.11.  > 8m dia.10 Floating Roof : 5.D. 5.10.1 Unless otherwise specified floating roof shall be of following construction. 5.Minimum nozzle Size : 40 NB . 5. < 36 dia Dia. Size of manhole shall be 500 mm minimum. > 36m 2 4 2 2 Floating roofs (pontoon or double deck type) shall be provided with manholes to inspect the entire interior of the roofs.11 Nozzle size : Unless otherwise specified .1 a) All nozzles and man-ways including self-reinforced type shall be 'set in' type and attached to vessel with full penetration welds.12 Flanges U V PATEL COLLEGE OF ENGINEERING  Page 27  . . 5. b) Self reinforced nozzles up to 80mm NB may be 'set on' type.Self Reinforced Nozzle Neck : Based on I. Foam seal of proven make shall be provided unless otherwise specified. Column : 50 NB .2 Floating roof design shall be in fabricators scope having proven track record.10.Safety Valve Nozzle : Based on I.Minimum Nozzle Size.D.

Slip on flanges may be used for nozzles above 100NB in Class 150 rating only. 5. 5.3 Slip on flanges shall not be used in Lethal. 10 % (Minimum two in each size) of installed fasteners. severe cyclic service and corrosive service (where corrosion allowance is in excess of 3mm).12.0 to 71. All flanges above Class 150 rating shall be weld neck type 5.5 and above 600 NB shall be as per ASME /ANSI B 16.0 and smaller 6.13 Internals : Removable internals shall be bolted type and bolting shall be stainless steel Type 304.0 71.47 (SERIES 'B') 5. m3 (mm) 6. NB (mm) DRAIN SIZE. vent/drain connection as per following : VESSEL VOLUME.1 Unless otherwise specified nozzle flanges up to 600NB shall be as per ASME /ANSI B16.0 and larger 40 40 50 80 40 50 80 100 VENT SIZE. only weld neck flange shall be used.12. 5. 4 sets for each installed glass. unless specified otherwise.0 to 17.  5.0 17. Hydrogen.14 Spares : Gaskets : Fasteners: Sight/Light Glass: Two sets for each installed gasket.12. caustic.15 Vent/Drain Connections: Vessel shall be provided with one number each.2 For nozzles 100 NB and below. NB U V PATEL COLLEGE OF ENGINEERING  Page 28  .

WHICH REQUIRES TESTING OF INDIVIDUAL PLATES FOR LOW TEMPERATURE SERVICE. CARBON STEEL MATERIAL IS ORDERED TO MEET THE IMPACT REQUIREMENTS OF SUPPLEMENT OF STANDARD ASME SA 20. shall be provided with pipe davit per relevant standard.0 INSULATION THICKNESS : As indicated on process data sheet by process licensor 7. 9. Annexure : I 1.0 MATERIAL SELECTION : Material of various parts of equipment shall be selected per process data sheet guidelines and proper care shall be taken for the points as given in Annexure.16 Pipe Davit : Vertical Vessel / Column having safety valve size > 80 NB and or having internals.0 STATUTORY PROVISIONS : National laws and statutory provisions together with any local byelaws for the state shall be complied with. TYPICAL U V PATEL COLLEGE OF ENGINEERING  Page 29  . PRESSURE VESSEL STEEL PLATES ARE PURCHASED TO THE REQUIREMENT OF THE STANDARD ASME SA-20. 8.0 SPECIAL CONSIDERATION FOR TALL COLUMN DESIGN Mechanical design of self supporting Tall Column / Tower shall be carried out for various load combinations as per Annexure-II 10.0 PAINTING As per Standard Specification.  5.I or as specified. 6. unless otherwise stated.

CHECK FOR IMPACT TESTING REQUIREMENT AS PER UCS-66 FOR COINCIDENT TEMPERATURE AND PART THICKNESS. MATERIAL SHALL BE SELECTED AS PER API 650 /API 620 AS APPLICABLE. 5. 6. MATERIAL FOR PRESSURE VESSELS DESIGNED ACCORDING TO ASME SECTION VIII DIVISION 2 SHALL BE GIVEN SPECIAL CONSIDERATION AS PER CODE. 9. ATMOSPHERIC/LOW PRESSURE STORAGE TANKS. NONFERROUS MATERIAL AND SUPER ALLOYS SHALL BE SELECTED BASED ON SPECIFIC RECOMMENDATION.  MATERIAL SPECIFICATION IS AS FOLLOWS SA 516 GR. NORMALISED TO MEET IMPACT REQUIREMENTS PER SUPPLEMENT SS OF SA 20 AT-50F 2. ALL PERMANENT ATTACHMENTS WELDED DIRECTLY TO 9 % NICKEL STEEL SHOULD BE OF THE SAME MATERIAL OR OF AN AUSTENTIC STAINLESS STEEL TYPE WHICH CANNOT BE HARDENED BY HEAT TREATMENT. SELECTION OF STAINLESS STEEL MATERIAL SHALL BE BASED ON PROCESS RECOMMENDATION/PROCESS LICENSOR. U V PATEL COLLEGE OF ENGINEERING  Page 30  . ALL PIPES SHALL BE OF SEAMLESS CONSTRUCTION. 3. 7.60. 4. 8. MATERIALS FOR CAUSTIC SERVICE SOUR SERVICE OR SOUR + HIC SHALL BE SELECTED BASED ON SPECIFIC RECOMMENDATION OF PROCESS LICENSOR.

1. Annexure -II DESIGN PHILOSOPHY OF TALL COLUMNS Mechanical design of self-supporting tall column and its anchorage block shall be carried out considering combination of various loads. wherever applicable.  10. Additional wind loading on column due to external attachments like platforms. MATERIAL FOR VESSEL /COLUMN SKIRT SHALL BE THE SAME MATERIAL AS OF VESSEL/ COLUMN SHELL FOR THE UPPER PART WITH A MINIMUM OF 500MM. 1. The weight of attachments to be considered shall be as per Table -1 enclosed Other loading as specified in UG-22 of ASME Code Sec. manholes.2 Internal and or external design pressure specified on process data sheets. nozzles. ladders. platforms.3 Seismic forces and moments shall be computed in accordance with IS 1893 (latest edition). 1. welded and removable attachments. Self weight of column inclusive of piping.4 Basic wind pressure and wind velocity (including that due to winds of short duration as in squalls) for the computation of forces / moments and dynamic analysis respectively shall be in accordance with IS 875 (latest edition). 1. U V PATEL COLLEGE OF ENGINEERING  Page 31  .0 Loadings The loadings to be considered in designing a self-supporting tall column/tower shall include: 1. ladders piping and attached equipment should be given due consideration. Unless otherwise specified importance factor and damping coefficient shall be considered as 2 and 2% respectively. VIII Div. insulation and operating liquid etc. 1.5 Loadings resulting in localised and gross stresses due to attachment or mounting of reflux / reboiler / condenser etc. trays.1 1.

4 Test Condition: Column (in corroded condition) under test pressure filled with water plus 33% of specified wind load on uninsulated column considered. 3. skirt shall be gradually flared to reduce the deflection. platforms.0 Deflection of Column Analysis shall be carries out for following conditions : Maximum allowable deflection at top of column shall be equal to height of the column divided by 200.1 Loading Condition Erection Condition: Column (un-corroded) erected on foundation without insulation. platforms.0 2. or earthquake force. insulating and operating liquid etc. the thickness of shell courses shall be increased one starting from bottom course above skirt and proceeding upwards till the deflection falls within allowable limits. EARTHQUAKE AND WIND SHALL BE CONSIDERED NOT ACTING CONCURRENTLY 3. Flaring of skirt shall be stopped if the deflection falls within limits or half angle of cone reaches maximum limit of 9 deg.1 If the deflection of column exceeds the above allowable limit the thickness of skirt shall be increased as first trial up to a maximum value equal to the column thickness and this exercise shall be stopped if the deflection falls within allowable limit.3 If the above two steps prove inadequate in limiting the deflection within allowable limits. 3. but with welded attachments plus full wind on column. trays removable internals.  2. trays etc.2 If the above step is inadequate. plus full wind on insulated column with all other projections open to wind. piping. including welded items. ladder.2 Operation Condition: Column (in corroded condition) under design pressure.3 2. 3. 2. reboiler mounted on column. 2. U V PATEL COLLEGE OF ENGINEERING  Page 32  .

5 6. 1000 mm Page 33  U V PATEL COLLEGE OF ENGINEERING  .7 Weight of trays (with liquid) to be considered.3 x design pressure x temperature correction factor as specified in ASME Code Section VIII Div. 3. 6./m2 Weight of plain Ladder: 15 Kg.0 Minimum Hydrotest Pressure Minimum Hydrotest Pressure (in Horizontal position) shall be equal to 1. TABLE-1 DETAILS AND WEIGHT OF COLUMN ATTACHMENT 1.0 Skirt Support Base Base supporting including base plate. The recommended magnification amplitude shall be limited to tower diameter divided by five.0 Stress Limits The stresses due to pressure weight wind / seismic loads shall be combined using maximum principle stress theory for ASME Section VIII Div. I./m Equivalent projection to be considered for wind load on caged ladder : 300 mm Distance of platform below each manhole : Approx. Numbers of foundation bolts shall be in multiple of four. : 120 Kg. 4. shall be designed based on overturning moment (greater of seismic or wind). anchor chairs compression ring. I (Clause UG-99) at top of column. 7./m Weight of caged ladder: 37 Kg.  4. A minimum number of 8 foundation bolts shall be provided.0 Dynamic Analysis Dynamic analysis of each column shall be carried out for stability under transverse wind induced vibrations as per standard design practice. 5. foundation bolting etc. Shape factor for shell (for wind force calculation) : 0. Thicknesses are accordingly chosen to keep the within limits as per Table-2. 2.

90xY. depending on extent of radiography. B = 'B' value calculated as per Clause UG-23 (b). 1200 mm for column dia. E = Weld joint efficiency of circumferential weld. 9.PxE LONGITUDINAL COMPRESSIVE STRESS Where KxB KxSxE ERECTION TEST NEW CORRODED AMBIENT DESIGN KxSxE KxB B S = Basic allowable Tensile Stress as per Clause UG 23 (a) of ASME Code Sec.1. Equivalent height of platform (for wind load computation) : 1000 mm Weight of platforms : 170 Kg. from column insulation surface./m2. column. U V PATEL COLLEGE OF ENGINEERING  Page 34  . VIII Div. Maximum distance between consecutive platform : 5000 mm Projection of Platform : 900mm up to 1meter dia.  7./ CONDITIONS TYPE OF STRESSES OPERATING NEW OR CORRODED CORRODED TEMPERATURE AMBIENT LONGITUDINAL 0. 11. 8.> 1 meter. Platform shall be considered all around TABLE -2 ALLOWABLE STRESSES FOR COMBINED LOADING VESSEL CONDITION / TEMP. 10.

if joint is shear type. b) 0. Note : Allowable stresses in skirt to shell joint shall be as per following : a) 0. U V PATEL COLLEGE OF ENGINEERING  Page 35  . 1. if joint is compression type.49S.70S.  K = Factor for increasing basic allowable value when wind or seismic load is present.2 as per ASME Sec VIII Div 1.

  CHAPTER 3 DESIGN PROCEDURE AND CALUCULATION U V PATEL COLLEGE OF ENGINEERING  Page 36  .

t = Thickness of the shell. Let. p = Intensity of internal pressure. In other words. We know that total force on a longitudinal section of the shell = Intensity of pressure × projected Area = p × d × l and the total resisting force acting on the cylinder walls = σ t1 × 2t × l …ii From equation (i) and (ii) . we have …. d = Internal diameter of the cylinder shell.(Q of two section) ….i U V PATEL COLLEGE OF ENGINEERING  Page 37  .  DESIGN THEORY Circumferential or Hoop Stress A tensile stress acting in a direction tangential to the circumference is called Circumferential or Hoop Stress. l = length of cylinder. it is on longitudinal section(or on the cylinder walls). and σ t1 = hoop stress for the material of the cylinder.. Now.

Fig of Longitudinal stress Let σ t 2 = Longitudinal stress.  σ t1 × 2t × l = p × d × l …. = Intensity of pressure × Cross.t From equation (i) and (ii). In other words. it is a tensile stress acting on the transverse or circumferential section.ii or σ t1 = p×d 2t or t = p×d 2σ t1 Longitudinal Stress A tensile stress acting in a direction of the axis is called longitudinal stress.. we have σ t 2 × πd.sectional Area =p× π (d)² 4 ………i ………ii In this case.t = p × σt 2 = π (d) ² 4 p×d p×d or t = 4σ t 2 4t Page 38  U V PATEL COLLEGE OF ENGINEERING  . the total force acting on the transverse section and total resisting force = σ t 2 × πd.

The shallow forming reduces manufacturing cost.  Design of Shell Due to Internal Pressure As discussed in article on thin vessel are cylindrical pressure vessel is subjected to tangential ( σ t ) and longitudinal ( σ L ) stresses. Pi × ( Di + t ) 2t η ×σ = η × σ × 2t = Pi × ( Di + t ) t= Pi × Di 2(η × σ ) − Pi Design of Elliptical Head: Elliptical heads are suitable for cylinders subjected to pressures over 1. Considering the joint efficiency. σt = Pi × Di P × Di and σ L = i 2t 4t where D= mean diameter = Di + t Rule The design pressure is taken as 5% to 10% more than internal pressure. It’s thickness can be calculated by the following equation: U V PATEL COLLEGE OF ENGINEERING  Page 39  .5 MPa. The thickness of shell can be found by following procedure. where as the test pressure is taken as 30% more than internal pressure.

6) 1 W = (2 + 22 ) 6 =1 t= Pi ⋅ di ⋅W 2 ⋅σ ⋅ J Design of Manhole Let.  t= where. tn = Actual thickness of nozzle trn = Required thickness as per calculation in mm t rn = Pi × Di 2 × σ ×η − Pi U V PATEL COLLEGE OF ENGINEERING  Page 40  . Of nozzle d = d i + 2 CA where.5d i = Major Axis Diameter c pi diW 2σ J Rule > Generally. di = Major axis of ellipse W= Stress intensification factor 1 W = (2 + k 2 ) 6 Where . CA = corrosion Allowance in mm t = Actual thickness of shell in mm tr = require thickness as per calculation in mm. d i = internal dia. k = 2 ( how ever k should not be greater than 2. k= Major Axis Diameter 0.

5 ( t – CA) or or or h = 2. Of Reinforcing Pad in mm d ip = inner dia.  h1actual = Height of the nozzle above the shell in mm h 2actual = Height of the nozzle below the shell in mm h1 = Height till where the effect of the nozzle persists above the shell in mm h 2 = Height till where the effect of the nozzle persists below the shell in mm To calculate h1 and h 2 consider a term ‘h’ h = 2. or X= di + t + tn -3CA 2 (whichever is maximum) d op = outer dia.5 ( tn – CA) (whichever is smaller) (whichever is smaller) (whichever is smaller) h1 = h h2 = h centre line h1actual h 2actual X = Distance where the effect of the nozzle persists in mm on each side of the X = d. Of Reinforcing Pad in mm t p = Thickness of Reinforcing Pad in mm U V PATEL COLLEGE OF ENGINEERING  Page 41  .

707 × tW × LW × n ∑W 0.707 × tW × LW × n τ W = w2 Where. A = d × tr A1 = (2X – d ) ( t – tr –CA) A2 = 2h1(tn – trn – CA) Excess area in the nozzle inside the shell A3 = 2 h2 (tn – 2CA) A r = ( d op . then the shear stresses in the weld will be given by: ∑W 2 P2 = KP 1 H 2 Do mm 0. Area Required. Excess area in the Shell. P 1 lies between 400 N/ mm and P 2 may be upto 2000 N/ m . legs can be made detachable to the vessel. Therefore. B) Wind Load Wind load can be estimated as : Pw1 = K P H Do 1 This equation is valid for heights upto 20m. Pw 2 = KP2 H 2 Do 2 2 Generally. These types of supports are suitable only for small vessels as there is a concentrated local stress at the joint.d ip ) t p Ar = A – ( A1 + A2 + A3) When Ar = 0 or negative. Excess area in the Nozzle. The design for leg supports is similar to that for bracket support. Beyond 20m. no reinforcement is necessary as the vessel thickness self Design of Leg: A) Legs support In certain cases. τW = tW = Weld Height LW = Weld Length. the bending moment due to wind at the base will be U V PATEL COLLEGE OF ENGINEERING  Page 42  . the wind pressure is higher and hence for heights above 20m.  Area Calculation Area pertaining to material removed. compensates. If the legs are welded to the shell. These legs can be bolted to plates. Area required.

bending stress will be. σbw = Mw = Mw = Pw1h1 2 Pw1h1 h + Pw 2 ( h1 + 2 ) 2 2 Mw z Where Z= section Modulus The wind load would create tensile stress on the wind side and compressive on the other side. U V PATEL COLLEGE OF ENGINEERING  Page 43  .  (IF H ≤ 20 m) (IF H> 20m) Therefore.

6) 1 W = (2 + 22 ) 6 =1 t= Pi ⋅ di ⋅W 2 ⋅σ ⋅ J where.588 MPa Internal Diameter (Di) = 496mm Corrosion Allowance (CA) = Nil.588) × (496) 2 ×137 × 1 − 0. As per Equation.066mm 2) Elliptical Head 1 W = (2 + k 2 ) 6 where .5d i Major Axis Diameter = Major Axis Diameter c k=2 Rule > Generally. t= t= Pi × Di + CA 2 × σ ×η − Pi (0. k = 2 ( how ever k should not be greater than 2. Joint Efficiency for shell = 1.066 ∴ t = 1.  Design Calculation 1) Thickness of cylinder Given data Internal pressure (P) = 0. U V PATEL COLLEGE OF ENGINEERING  Page 44  .588 (Q CA is NIL) = 1. k= 0.

51 mm. CA = NIL Joint Efficiency (η ) = 1 Internal diameter of nozzle (di) = 254. trn = Required thickness as per calculation in mm. tr = require thickness = 1.588 t 1 rn = t rn = 0.27 mm.51 mm d = di + CA = 254. 0.06 mm ∴ t = 1.588 N/ mm 2 Internal diameter (Di) = 496 mm Thickness (t) = 6 mm.588 × 496 × 1 2 ×137 × 1 = 1.51 Pi × Di 2 × σ ×η − Pi A = 2 ×137 ×1 − 0.51 2 × 137 × 1 − 0.588 × 254.06 mm 3) Design Of Manhole INLET NOZZLE (N1) GIVEN DATA Internal pressure (Pi) = 0.  di = Major axis of ellipse = 496mm W = Stress intensification factor = 1 Pi ⋅ di ⋅W 2 ⋅σ ⋅ J t= t= 0.066 mm.588 × 254.588 U V PATEL COLLEGE OF ENGINEERING  Page 45  . tn = Actual thickness of nozzle = 9.

X = di + t + tn -3CA 2 = 254. A1 = (2X – d ) ( t – tr –CA) Generally.27-0) U V PATEL COLLEGE OF ENGINEERING  Page 46  or h = 2.5 (9. t rn = 0.52 mm. A = d × tr = 254.547 mm. A = (2 × 254.  = 0. X = d = 254. A2 = 2h1(tn – trn – CA) h = 2.5 × 6 = 15mm h1 = h2 = h = 15 mm.51 mm.3 mm2 Excess area in the shell.51 + 6 +9. Therefore.066 = 271.51)(6-1.5 ( tn – CA) = 2.51 × 1.547 – 0) = 261.27 – 0 2 = 142. ( Take X whichever maximum) Therefore.51-254.066-0) = 1255.547 mm. Area Calculation Area Pertaining to material removed.75 mm2 Excess area in the nozzle.27 – 0.69 mm 2 Excess area in the nozzle inside the shell A3 = 2 h2 (tn – 2CA) = 2 × 15 ( 9.5 ( t – CA) = 2. A2 = 2 × 15 ( 9.27) = 23.175 mm ( Take X whichever smaller) .

  = 278. K = Coefficient depending on shape factor = 0. Z = section Modulus Z= 3 bh 3 − b1h1 6h U V PATEL COLLEGE OF ENGINEERING  Page 47  .41 N. 4) Design of leg Wind load Here .1 mm 2 Area required Ar = A – ( A1 + A2 + A3) = -1524. Mw = Pw1h1 2 Mw = Mw = Pw1h1 2 Pw1h1 h + Pw 2 ( h1 + 2 ) 2 2 = 626.7 P = Wind pressure = 730 N/ mm 2 1 H = Height of the vessel above foundation =2413 mm Do = Outer Diameter Of Vessels Wind load can be estimated as : Pw1 = K P H Do 1 = 0.47 = 755.24 As Ar is –ve or zero reinforcement is not necessary.38 × 1206.7×730×2.38 N (IF H ≤ 20 m) (IF H> 20m) Here we use .Section.413×0. Therefore.508 = 626.m Here we use I.

σbw = Mw z 755.96 t 3 Therefore.  = 4t(5t)3 − 3t(3t)3 6(5t) = 13. Bending Stress will be .36 × 10−3 m ∴ L= 123 123 + + 1834 3 3 = 1916 mm U V PATEL COLLEGE OF ENGINEERING  Page 48  .41 13.96t 3 (as σ bw = 350 N/mm²) 350× 106 = t = 5.

  SUMMARY    SHELL     HEAD      MAN HOLE     REINFORCEMENT  PAD     LEG       INTERNAL DIAMETER (Di)  LENGTH (L)  THICKNESS (t)  THICKNESS (t)  HEIGHT (h)  DIAMETER OF OPENING (di)  THICKNESS OF NOZZLE (tn)  AS AREA CALCULATED IS   ‐ve      RF PAD IS NOT REQUIRED        THICKNESS OF LEGS      496mm  1734mm   6mm                                   6mm                              173mm  254.36mm                                    U V PATEL COLLEGE OF ENGINEERING  Page 49  .51  9.27                                  5 .

  DESIGN CODES APPROCH 2 BY ASME U V PATEL COLLEGE OF ENGINEERING  Page 50  .

14 1.  DESIGN THEORY PRESSURE VESSEL HEAD DESIGN UNDER INTERNAL PRESSURE THICKNESS OF HEADS/ CLOSURES: ELLIPSOIDAL HEAD: t t K MAJOR & = P.83 1.8 2.6 2.71 0.5 2.0 K 0.2 2.1P) + CA FOR KNUCKLE RADIUS.2P) + CA OTHERS.Di / (2SE.4 1.E.6 1.Di/ (2SE-0.1 2. r = 6% OF CROWN RADIUS (L) t =PLM/ (2S.2P) + CA =CONSTANT BASED ON THE MINOR AXIS (D/2H) RATIO OF “VALUES OF FACTOR K” D/2H 3.2 1.0.8 1.0 K 1.885 PL/ (SE-0.64 1. = P.29 1.0 2.4 2.57 0.K.00 D/2H 1.46 1.0.07 1.5 1.2P) + CA where L=CROWN RADIUS M=CONSTANT BASED ON RATIO OF RADIUS(L/r) CROWN AND KNUCLE U V PATEL COLLEGE OF ENGINEERING  Page 51  .50 TORISPHERICAL HEAD: t= 0.87 0.66 0.76 0.37 1.

0.  “VALUES OF FACTOR M” L/r 1.0 13.1 – 0.6P) + CA α = half apex angle HEMISPHERICAL HEAD: t = P.46 1.54 L/r 12.50 2.0 9.0 L/r 5.0 1.34) CIRCULAR COVER/ HEADS t = Di * SQRT(CP/SE) + CA Where C = Factor.0 8.33) OBROUND/ NON-CIRCULAR HEADS (INCLUDING SQUARE/ RECTANGULAR) U V PATEL COLLEGE OF ENGINEERING  Page 52  .65 1.75 1.00 1.0 M 1.36 1.69 1.58 1.0 15.62 1.2P) + CA FLAT HEADS & COVERS (UG.10 1.18 1.50 3.0 10.06 1.31 1. r SHALL NOT BE LESS THAN 3t.00 3.0 16.22 6.0 14.00 2.72 1. dependent on joint geometry of head cover to shell (range 0.77 (USE NEAREST VALUE OF L/r.67 M 1.25 11.50 4.50 1.Ri/ (2SE.0 7.41 1.15 1.0 16. KNUCKLE RADIUS.0 M 1. CONICAL HEAD: t = PDi/ 2 COS α (SE-0.0 1. INTERPOLATION UNNECESSARY) NOTE: – MAXIMUM RATIO ALLOWED BY UG-32 (j) WHEN L EQUALS THE OUTSIDE DIAMETER OF THE SKIRT OF THE HEAD.

4 .(2. Suggested Good Practices Inclusions: – Unfired Steam Boilers/ Generators Evaporators Heat Exchangers – Direct Fired Vessels Gas Fired Jacketed Steam Kettles(Jacket Pressure less than 50 PSI) Additional Interpretation: U V PATEL COLLEGE OF ENGINEERING  Page 53  . Specifications – Mandatory Appendices Specific Important Subjects to Supplement Subsections – Non-Mandatory Appendices Additional Information. Guidelines.4 d / D) + CA PRESSURE VESSEL SHELL COMPONENT DESIGN UNDER INTERNAL PRESSURE Pressure Vessel Definition: – Containers of Pressure Internal External – Pressure Source External Application of Heat Code Coverage: – Subsections Rule.  t = Di * SQRT(Z*CP/SE) where Z = 3.

– Other standards for components are acceptable Guidelines for Designed Thickness (To be adopted): – (1/16)” excluding corrosion allowance for shell & head (Min. THICKNESS CALCULATIONS UNDER INTERNAL PRESSURE.Di/ 2COSα(SE. CYLINDRICAL SHELL: Circumferential stress: U V PATEL COLLEGE OF ENGINEERING  Page 54  .0.Ri / (2SE+0. Such additional design & construction procedure may be adopted which are safe and acceptable. for unfired steam boiler shell – (3/32)” min.  – The code rules may not cover all designs & constructions procedures.6P) + CA Stress Calculation UNDER INTERNAL PRESSURE.6P) + CA Longitudinal stress: t = P.0.2P) + CA CONICAL SECTION: (INTERNAL PRESSURE) t =P. – Field fabrication are acceptable.) – The above will not apply to heat transfer surface – (1/4)” min.Ri / (SE. excluding corrosion allowance for compressed air/ steam/ water service(for CS/AS) – Corrosion allowance shall be based on experience/ field data(No value/ code recommended).4P) + CA SPHERICAL SHELL: t = P.Ri / (2SE.0. CYLINDRICAL SHELL: Circumferential stress: t = P.

0.  Sc = P (Ri + 0.8tCOSα)/4Et COSα U V PATEL COLLEGE OF ENGINEERING  Page 55  .2 tCOSα)/2Et COSα Sl =P (Di – 0.2t)/ 2Et CONICAL SHELL SECTION: Sc =P (Di + 1.4t)/ 2Et SPHERICAL SHELL: Sc = P (Ri + 0.6t)/ Et Longitudinal stress: Sl = P (Ri .

May 25. May 25. 2008 at 10:04:27 PM Project Last Modified Sunday. 2008 at 10:04:27 PM U V PATEL COLLEGE OF ENGINEERING  Page 56  .  ANALYSIS OF PRESSURE VESSEL Project Author jimit and mahavir Subject shell analysis Prepared For project report Project Created Sunday.

Multiple scenarios allow comparison of results given different loading conditions. and types and magnitudes of loading conditions. A quality approach to engineering design usually mandates physical testing as the final means of validating structural integrity to a measured precision. Notice Do not accept or reject a design based solely on the data presented in this report. Solution history provides a means of assessing the quality of results by examining how values change during successive iterations of solution refinement. s. The definition of a simulation includes known factors about a design such as material properties per body. °C. kg. Convergence criteria sets a specific limit on the allowable change in a result between iterations. V. to generate the results listed in this report. contact behavior between bodies (in an assembly). Each scenario presented below represents one complete engineering simulation. N. Convergence and alert criteria may be defined for any of the results and can serve as guides for evaluating the quality of calculated results and the acceptability of values in the context of known design requirements. materials or geometric configurations. U V PATEL COLLEGE OF ENGINEERING  Page 57  . The results of a simulation provide insight into how the bodies may perform and how the design might be improved. Alert ranges typically represent known aspects of the design specification. ANSYS automated FEA (Finite Element Analysis) technologies from ANSYS. Alert criteria define "allowable" ranges for result values. Inc. A result meeting this criteria is said to be "converged". All values are presented in the "SI Metric (m.  1 Introduction The ANSYS CAE (Computer-Aided Engineering) software program was used in conjunction with 3D CAD (Computer-Aided Design) solid geometry to simulate the behavior of mechanical bodies under thermal/structural loading conditions. A)" unit system. Evaluate designs by considering this information in conjunction with experimental test data and the practical experience of design engineers and analysts.

1. 0.2. No mesh controls specified. 2. 1.0 Pa N/A 2. Scenario 1 2.71×10-3 N Reaction Force Vector Reaction Moment Reaction Moment Vector [1.67×10-9 N z] U V PATEL COLLEGE OF ENGINEERING  Page 58  . 1. Structural Loads Name Type Magnitude Vector Reaction Force N/A Reaction Vector N/A Force Reaction Moment N/A Reaction Vector N/A Moment "Pressure" Pressure 600. Table 2.16×10-9 N·m y.69 1.52.1.1.2". "Model" "Model" obtains geometry from the Pro/ENGINEER® cylinder\SHEEL. "Mesh" contains 4968 nodes and 684 elements. Structural Supports Name "Fixed Support" Type Fixed Surface Reaction Force 1.2.000. Mesh "Mesh".81×10-5 N·m x.PRT.2.69 kg.2. 0.1.73 by 0. Structural Supports Table 3.81×10-5 N·m 3.2. Bodies Name Material Nonlinear Material Effects Bounding Box(m) Mass (kg) Volume (m³) Nodes Elements 1.4×10-2 m³.71×10-3 N x.1.1.1. associated with "Model" has an overall relevance of 0.06×10-7 N·m z] [-1.52 by 0. 2. 3. The model has a total volume of 1.1.1. y and z axes. "Environment" Simulation Type is set to Static Analysis Type is set to Static Structural "Environment" contains all loading conditions defined for "Model" in this scenario.73.2. 1.52 m along the global x. part "H:\shaell and The bounding box for the model measures 1. Structural Loading Table 3.4×10-2 4968 684 "SHEEL" "Structural Steel" Yes 2. The model has a total mass of 109.16×10-7 N y.  2. respectively.52 109.2.

at a uniform temperature of 22. Equivalent Stress Safety Table 3. Structural Results Table 3.1. 2. Values Name Figure Scope Minimum Maximum Minimum Occurs Maximum Occurs Alert On On Criteria "Equivalent Stress" A1.5×107 Pa SHEEL SHEEL None "Maximum Stress" Shear None "Model" 4.3.  2.0 °C for "SHEEL". Thermal expansion calculations use a constant reference temperature of 22.3.2 "Model" 0.6×106 Pa 3. Table 3.2.0 °C no strain results from thermal expansion or contraction.3.1.0 m 4.96×106 Pa 1.3.2.13 None None "Stress Tool" "Model" "Stress Tool" "Model" Safety Margin 6. 2. Definition Name Stress Limit "Stress Tool" Yield strength per material. Results Name Scope Type Safety Factor Minimum Alert Criteria 7.3.1. Theoretically.2.3.1 "Model" 8.1.1.3.3.87×107 Pa SHEEL SHEEL None "Total Deformation" A1.3. Shear Stress Safety Table 3.2.13 Convergence tracking not enabled. "Solution" Solver Type is set to Program Controlled Weak Springs is set to Program Controlled Large Deflection is set to Off "Solution" contains the calculated response for "Model" given loading conditions defined in "Environment".3.27×10-5 m SHEEL SHEEL None Convergence tracking not enabled. Definition Name Shear Limit Shear Factor U V PATEL COLLEGE OF ENGINEERING  Page 59  . 2.

"Equivalent Stress" Contours U V PATEL COLLEGE OF ENGINEERING  Page 60  .69 None None "Stress Tool 2" "Model" "Stress Tool 2" "Model" Safety Margin 5.  "Stress Tool 2" Yield strength per material.2. stress Figure A1.3.1.69 Convergence tracking not enabled.3.5 Table 3. Results Name Scope Type Safety Factor Minimum Alert Criteria 6. 0.

  Scenario 1 Figures deformation Figure A1.2. "Total Deformation" Contours U V PATEL COLLEGE OF ENGINEERING  Page 61  .

2×10-5 1/°C 434.6×108 Pa 2. Definition of "Structural Steel" Table A2.0 Pa 2.  AppendicesA1.1.5×108 Pa 4.0 J/kg·°C 60.000. A2.2.5 W/m·°C 10. "Structural Steel" Constant Properties Name Compressive Ultimate Strength Compressive Yield Strength Density Poisson's Ratio Tensile Yield Strength Tensile Ultimate Strength Young's Modulus Thermal Expansion Specific Heat Thermal Conductivity Relative Permeability Resistivity Table A2.0 1.3 2.5×108 Pa 7.0×1011 Pa 1.7×10-7 Ohm·m U V PATEL COLLEGE OF ENGINEERING  Page 62  .0 kg/m³ 0. Alternating Stress Value 0.850.

0 50. "Alternating Stress" Cycles 10.38×108 Pa 1.21 U V PATEL COLLEGE OF ENGINEERING  Page 63  .000.000.62×107 Pa Table A2.5.0 200.0×109 Pa 2.41×108 Pa 2.3. "Strain-Life Parameters" Strength Coefficient Strength Exponent Ductility Coefficient 9.000.07×109 Pa 4.000.9×109 Pa 1.11 0.000.2×108 Pa -0.0 20.0 1.000.14×108 Pa 1.0 10.41×109 Pa 1.62×108 Pa 2.0 20.0 100.0 2.14×108 Pa 8.0 Alternating Stress 4.0 Table A2.000.0 100.  Mean Value 0.4.83×109 Pa 1.0 200. Strain-Life Parameters Table A2.

47 1.2 U V PATEL COLLEGE OF ENGINEERING  Page 64  .  Ductility Exponent Cyclic Strength Coefficient Cyclic Strain Hardening Exponent -0.0×109 Pa 0.

2008 11. May 25. May 25.0 Release U V PATEL COLLEGE OF ENGINEERING  Page 65  . 2008 Sunday.  Project Author Subject Prepared for First Saved Last Saved Product Version Jimit vyas and mahavir solanki Ellipsoidal dish end project analysis Sunday.

173 m 3 U V PATEL COLLEGE OF ENGINEERING  Page 66  . kg. V. N. °C. A) Angle Degrees Rotational Velocity rad/s Model Geometry TABLE Model > Geometry > Parts Object Name State Graphics Properties Visible Transparency Definition Suppressed Material Stiffness Behavior Nonlinear Material Effects Bounding Box Length X Length Y Length Z ELIPTICALHEAD Meshed Yes 1 No Structural Steel Flexible Yes 0.508 m 0.  Contents • Model o Geometry ELIPTICALHEAD o Mesh CFX-Mesh Method o Static Structural Analysis Settings Loads Solution Solution Information Results Max Equivalent Stress Results Max Shear Stress Results Material Data o Structural Steel • Units TABLE 1 Unit System Metric (m. s.508 m 0.

0962e-017 m -3.343 kg·m² 0.9271e-003 m³ 15.1168e-017 m 1.128 kg -8.34417 kg·m² 0.6178 kg·m² 2289 6232 Mesh TABLE Model > Mesh Object Name State Defaults Physics Preference Relevance Advanced Relevance Center Element Size Shape Checking Solid Element Midside Nodes Straight Sided Elements Initial Size Seed Smoothing Transition Statistics Nodes Elements TABLE Model > Mesh > Mesh Controls Object Name State Scope Scoping Method Geometry Definition Suppressed Method Element Midside Nodes Mesh Solved CFD 0 Fine Default CFD Dropped Active Assembly Medium Slow 2289 6232 5 CFX-Mesh Method Fully Defined Geometry Selection 1 Body No CFX-Mesh Dropped 4 Static Structural U V PATEL COLLEGE OF ENGINEERING  Page 67  .7996e-002 m 0.  Properties Volume Mass Centroid X Centroid Y Centroid Z Moment of Inertia Ip1 Moment of Inertia Ip2 Moment of Inertia Ip3 Statistics Nodes Elements 1.

e+005 Pa (ramped) No 1 U V PATEL COLLEGE OF ENGINEERING  Page 68  .  TABLE Model > Analysis Object Name State Definition Physics Type Analysis Type Options Reference Temp TABLE Model > Static Structural > Loads Object Name State Scope Scoping Method Geometry Definition Define By Type Magnitude Suppressed FIGURE Model > Static Structural > Pressure Static Structural Fully Defined Structural Static Structural 22. °C 8 Pressure Fully Defined Fixed Support 2 6 Geometry Selection 4 Faces 1 Face Normal To Pressure Fixed Support 6.

101e+006 Pa Maximum 3.1378e+007 Pa Information Time 1. TABLE Model > Static Structural > Solution > Solution Information Object Name Solution Information State Solved Solution Information Solution Output Solver Output Newton-Raphson Residuals 0 Update Interval 2.6131e+006 Pa 1.  Solution TABLE Model > Static Structural > Solution Object Name Solution State Solved Adaptive Mesh Refinement Max Refinement Loops 1.1032e-005 m Structural > Solution > Equivalent Stress > 2 Figure U V PATEL COLLEGE OF ENGINEERING  Page 69  . s Load Step 1 Substep 1 Iteration Number 1 FIGURE Model > Static equivalent stress 9 10 11 Maximum Shear Stress Total Deformation Maximum Shear Stress Total Deformation 1. m 4. Refinement Depth 2.5 s Display Points All TABLE Model > Static Structural > Solution > Results Object Name Equivalent Stress State Solved Scope Geometry All Bodies Definition Type Equivalent (von-Mises) Stress Display Time End Time Results Minimum 3.6963e+007 Pa 0.

  FIGURE Model > Static Structural maximum shear stress > Solution > Maximum Shear Stress > 3 Figure U V PATEL COLLEGE OF ENGINEERING  Page 70  .

  TABLE Model > Static Structural > Solution > Stress Safety Tools Object Name Max Equivalent Stress State Solved Definition Theory Max Equivalent Stress Stress Limit Type Tensile Yield Per Material TABLE Model > Static Structural > Solution > Max Equivalent Stress > Results Object Name Safety Factor Safety Margin State Solved Scope Geometry All Bodies Definition Type Safety Factor Safety Margin Display Time End Time Results Minimum 7.9674 12 13 U V PATEL COLLEGE OF ENGINEERING  Page 71  .9674 6.

s 1 1 1 14 TABLE Model > Static Structural > Solution > Stress Safety Tools Object Name Max Shear Stress State Solved Definition Theory Max Shear Stress Factor 0.e+011 Pa 0.  Information Time Load Step Substep Iteration Number 1.5 Stress Limit Type Tensile Yield Per Material TABLE Model > Static Structural > Solution > Max Shear Stress > Results Object Name Safety Factor Safety Margin State Solved Scope Geometry All Bodies Definition Type Safety Factor Safety Margin Display Time End Time Results Minimum 7. s Load Step 1 Substep 1 Iteration Number 1 15 Material Data Structural Steel TABLE Structural Steel > Constants Structural Young's Modulus Poisson's Ratio Density Thermal Expansion Tensile Yield Strength Compressive Yield Strength Tensile Ultimate Strength Compressive Ultimate Strength Thermal 16 2.5e+008 Pa 4.2e-005 1/°C 2.3 7850. kg/m³ 1.369 Information Time 1.369 6.6e+008 Pa 0. Pa U V PATEL COLLEGE OF ENGINEERING  Page 72  .5e+008 Pa 2.

1. 2. 3. TABLE Structural Steel > Alternating Stress > Alternating Stress vs.999e+009 20.896e+009 100.827e+009 50. J/kg·°C 10000 1. 1.5 W/m·°C 434.7e-007 Ohm·m 4 TABLE Structural Steel > Alternating Stress > Property Attributes Interpolation Log-Log Mean Curve Type Mean Stress TABLE Structural Steel > Alternating Stress > Alternating Stress Curve Data Mean Value Pa 0. Cycles Cycles Alternating Stress Pa 10.413e+009 17 18 19 U V PATEL COLLEGE OF ENGINEERING  Page 73  .  Thermal Conductivity Specific Heat Electromagnetics Relative Permeability Resistivity FIGURE Structural Steel > Alternating Stress 60.

213 Ductility Exponent -0.62e+007 5 TABLE Structural Steel > Strain-Life Parameters > Property Attributes Display Curve Type Strain-Life TABLE Structural Steel > Strain-Life Parameters > Strain-Life Parameters Strength Coefficient Pa 9.e+009 Cyclic Strain Hardening Exponent 0.38e+008 1.2e+008 Strength Exponent -0.  200.106 Ductility Coefficient 0. 10000 20000 1.e+006 FIGURE Structural Steel > Strain-Life Parameters 1.47 Cyclic Strength Coefficient Pa 1.14e+008 8.14e+008 1.62e+008 2.41e+008 2. 2000.2 20 21 U V PATEL COLLEGE OF ENGINEERING  Page 74  .e+005 1.e+005 2.069e+009 4.

March 18. 2008 Product Version 11.  FATIGUE ANALYSIS Project Author Subject Prepared for First Saved Last Saved JIMIT AND MAHAVIR FATIGUE ANALYSIS DESIGN AND ANALYSIS OF PRESSURE VESSEL Monday. 2008 Tuesday. March 17.0 Release U V PATEL COLLEGE OF ENGINEERING  Page 75  .

  Contents • Model o Geometry Mesh Static Structural FATIGUEANALYSIS o o Loads Solution Solution Information Results Max Equivalent Stress Results Max Shear Stress Results Fatigue Tool Results Result Charts goodman stress life rl Results • o Material Data Structural Steel 2 Analysis Settings Units TABLE 1 Unit System Angle Metric (m. kg. s. N. °C. A) Degrees Rotational Velocity rad/s U V PATEL COLLEGE OF ENGINEERING  Page 76  . V.

30847 m³ 2421.  Model Geometry TABLE Model > Geometry Object Name State Definition Source Type Length Unit D:\pressurevesselanalysis\fatigueanalysis\FATIGUEANALYSIS.782 m 2.3 ProEngineer Millimeters Geometry Fully Defined Element Control Program Controlled Display Style Bounding Box Length X Length Y Length Z Properties Volume Mass Statistics Bodies Active Bodies Nodes Elements 1 1 12181 6191 0.PRT.762 m 0.08 m Part Color TABLE Model > Geometry > Parts Object Name State FATIGUEANALYSIS Meshed U V PATEL COLLEGE OF ENGINEERING  Page 77  .5 kg 0.

 
Graphics Properties Visible Transparency Definition Suppressed Material Stiffness Behavior No Structural Steel 2 Flexible Yes 1

Nonlinear Material Effects Yes Bounding Box Length X Length Y Length Z Properties Volume Mass Centroid X Centroid Y Centroid Z Moment of Inertia Ip1 Moment of Inertia Ip2 Moment of Inertia Ip3 Statistics Nodes Elements 12181 6191 0.30847 m³ 2421.5 kg -2.3696e-003 m 2.1709e-003 m -8.3295e-004 m 522.75 kg·m² 522.8 kg·m² 80.459 kg·m² 0.762 m 0.782 m 2.08 m

Common Decisions to Both Types of Fatigue Analysis
Once the decision on which type of fatigue analysis to perform, Stress Life or Strain Life, there are 4 other topics upon which your fatigue results are dependent upon. Input decisions that are common to both types of fatigue analyses are listed below: • Loading Type • Mean Stress Effects
U V PATEL COLLEGE OF ENGINEERING  Page 78 

 
• Multiaxial Stress Correction • Fatigue Modification Factor Within Mean Stress Effects, the available options are quite different. In the following ections, we will explore all of these additional decisions. These input decision trees for fatigue analysis in both both Stress Life and Strain Life are outlined in Figures 1 and 2. in detail below.

predicted life and types of post processing available. We will look at each of these choices

Mesh
TABLE Model > Mesh Object Name State Defaults Physics Preference Relevance Advanced Relevance Center Element Size Shape Checking Coarse Default Standard Mechanical Mechanical 0 Mesh Solved

Solid Element Midside Nodes Program Controlled Straight Sided Elements Initial Size Seed Smoothing Transition Statistics Nodes Elements 12181 6191 No Active Assembly Low Fast

U V PATEL COLLEGE OF ENGINEERING 

Page 79 

 

Static Structural
TABLE Model > Analysis Object Name State Definition Physics Type Analysis Type Options Reference Temp 22. °C TABLE Model > Static Structural > Analysis Settings Object Name State Step Controls Number Of Steps 1. Analysis Settings Fully Defined Structural Static Structural Static Structural Fully Defined

Current Step Number 1. Step End Time 1. s Program Controlled TABLE Model > Static Structural > Loads Object Name State Scope Scoping Method Geometry Selection Geometry Definition Define By Type Magnitude Suppressed Normal To Pressure -6.e+005 Pa (ramped) No Fixed Support 10 Faces 2 Faces Pressure Fully Defined Fixed Support

U V PATEL COLLEGE OF ENGINEERING 

Page 80 

U V PATEL COLLEGE OF ENGINEERING  Page 81  .  FIGURE Model > Static Structural > Pressure Solution TABLE Model > Static Structural > Solution Object Name State Solution Obsolete Adaptive Mesh Refinement Max Refinement Loops 1. Refinement Depth TABLE Model > Static Structural > Solution > Solution Information Object Name State Solution Information Solution Output Solver Output Solution Information Not Solved 2.

5 s All Iteration Number 1 TABLE Model > Static Structural > Solution > Stress Safety Tools Object Name State Definition Theory Max Equivalent Stress Max Equivalent Stress Solved Stress Limit Type Tensile Yield Per Material TABLE Model > Static Structural > Solution > Max Equivalent Stress > Results Object Name State Scope Safety Factor Safety Margin Solved U V PATEL COLLEGE OF ENGINEERING  Page 82  .7782 Pa 6. m 4.5341e+007 Pa 0. s 1 1 4.  Newton-Raphson Residuals 0 Update Interval Display Points TABLE Model > Static Structural > Solution > Results Object Name State Scope Geometry Definition Type Display Time Results Minimum Maximum Information Time Load Step Substep 1.4722e+007 Pa 2.4133e-004 m Equivalent (von-Mises) Stress Maximum Shear Stress Total Deformation End Time All Bodies Equivalent Stress Solved Maximum Shear Stress Total Deformation 2.757 Pa 3.

  Geometry Definition Type Display Time Results Minimum Information Time Load Step Substep 1.537 Safety Factor Safety Margin End Time All Bodies Safety Factor Safety Margin Solved U V PATEL COLLEGE OF ENGINEERING  Page 83  .8627 2.5 Max Shear Stress Solved Stress Limit Type Tensile Yield Per Material TABLE Model > Static Structural > Solution > Max Shear Stress > Results Object Name State Scope Geometry Definition Type Display Time Results Minimum Information Time 1.8627 Safety Factor Safety Margin End Time All Bodies Iteration Number 1 TABLE Model > Static Structural > Solution > Stress Safety Tools Object Name State Definition Theory Factor Max Shear Stress 0.537 2. s 3. s 1 1 3.

  Load Step Substep 1 1 Iteration Number 1 TABLE Model > Static Structural > Solution > Fatigue Tools Object Name State Materials Fatigue Factor (Kf) Loading Type History Location Scale Factor Definition Display Time Options Analysis Type Stress Life End Time History Data Data C:\Program Files\Ansys Inc\v110\AISOL\CommonFiles\Language\enStrength 1. Proportional Loading U V PATEL COLLEGE OF ENGINEERING  Page 84  .e+009 cycles 5000.e-003 Mean Stress Theory Goodman Stress Component Bin Size Use Quick Rainflow Counting Infinite Life Maximum Points To Plot Life Units Units Name 1 block is equal to cycles 1.dat 5.e+006 cycles Data Equivalent (Von Mises) 32 Yes 1. Non-constant amplitude. Fatigue Tool Solved us\EngineeringData\Load Histories\sampleHistory2.

Thus. which can be compared to the available constant amplitude test data. Setting a higher value will make small stress cycles less damaging if they occur many times. But instead of using a single load ratio to calculate alternating and mean values. alternating andmean stresses are sorted into bins before partial damage is calculated. For Stress Life. the fatigue loading which causes the maximum damage cannot easily be seen. the critical fatigue location can be found by looking at a single set of FE results. if the alternating stress is lower than the lowest alternating stress on the fatigue curve. proportional loading within the ANSYS Fatigue Module uses a “quick counting” technique to substantially reduce runtime and memory. another available option when conducting a variable amplitude fatigue analysis is the ability to set the value used for infinite life. Think of this as coupling an FE analysis with strain-gauge results collected over a given time interval. However. Without quick counting.  Non-constant amplitude. the fatigue tool will use the life at the last point. The bin size defines how many divisions the cycle counting history should be organized into for the history data loading type. cycles with very small alternating stresses may be present and may incorrectly predict too much damage if the number of the small stress cycles is high enough. data is not sorted into bins until after partial damages are found. This provides for an added level of safety because many materials do not exhibit an endurance limit. Since loading is proportional. in non-constant amplitude loading. Cycle counting is a means to reduce a complex load history into a number of events. However. bin size specifies the number of divisions of the rainflow matrix. the load ratio varies over time. cumulative damage calculations (including cycle counting such as Rainflow and damage summation such as Miner’s rule) need to be done to determine the total amount of fatigue damage and which cycle combinations cause thatdamage. The Rainflow and damage U V PATEL COLLEGE OF ENGINEERING  Page 85  . In constant amplitude loading. In quick counting. proportional loading also needs only one set of FE results. meaning that the Rainflow Matrix is 32 x 32 in dimension. Non-constantAmplitude. the user can set the infinite life value that will be used if the alternating stress is beyond the limit of the SN curve. A larger bin size has greater precision but will take longer to solve and use more memory. Bin size defaults to 32. Strictly speaking. The accuracy of quick counting is usually very good if a proper number of bins are used when counting. To help control this.

FIGURE Model > Static Structural > Solution > Fatigue Tool FIGURE Model > Static Structural > Solution > Fatigue Tool U V PATEL COLLEGE OF ENGINEERING  Page 86  .  matrix results can be helpful in determining the effects of small stress cycles in your loading history.

50. Model > Static Structural > Solution > Fatigue Tool > Result Charts U V PATEL COLLEGE OF ENGINEERING  Page 87  .e+007 cycles 0.  TABLE Model > Static Structural > Solution > Fatigue Tool > Results Object Name Life State Scope Safety Factor Damage Solved Geometry Definition All Bodies Type Design Life Results Life Safety Factor Damage 1.e+009 cycles Minimum Maximum TABLE 2.

1628e+007 Pa Design Life 1. This result gives the user a measure of the composition of a loading history.) From the rainflow matrix figure. In this 3-D histogram.e+009 cycles FIGURE Model > Static Structural > Solution > Fatigue Tool > Rainflow Matrix Rainflow Matrix Chart Rainflow Matrix Chart is a plot of the rainflow matrix at the critical location.  Object Name State Scope Rainflow Matrix Damage Matrix Solved Geometry Options All Bodies Chart Viewing Style Three Dimensional Results Minimum Range Maximum Range Minimum Mean Maximum Mean Definition 0. Pa 1. This result may be scoped. alternating and mean stress is divided into bins and plotted. the user can see that most of the alternating stresses have a positive mean stress and that in this case the majority of alternating stresses are quite low.2328e+008 Pa 6. This result is onlyapplicable for non-constant amplitude loading where rainflow counting is needed. U V PATEL COLLEGE OF ENGINEERING  Page 88  . The Z-axis corresponds to the number of counts for a given alternating and mean stress bin.9246e+008 Pa -3. (Such as if most of the alternating stress cycles occur at a negative mean stress.

in this particular case although most of the counts occur at the lower stress amplitudes. As can be seen from the \corresponding damage matrix for the above rainflow matrix. This result may be scoped.  FIGURE Model > Static Structural > Solution > Fatigue Tool > Damage Matrix Damage Matrix Chart Damage Matrix Chart is a plot of the damage matrix at the critical location on the model. This result is only applicable for non-constant amplitude loading where rainflow counting is needed. This result is similar to the rainflow matrix except that the percent damage that each of the Rainflow bin cause is plotted as the Z-axis. most of the damage occurs at the higher stress amplitudes. U V PATEL COLLEGE OF ENGINEERING  Page 89  .

Loading Type Scale Factor Definition Fully Reversed 1. Display Time Options End Time Analysis Type Mean Stress Theory U V PATEL COLLEGE OF ENGINEERING  Stress Life Goodman Page 90  .  TABLE Model > Static Structural > Solution > Fatigue Tools Object Name State Materials goodman stress life rl Solved Fatigue Strength Factor (Kf) 1.

proportional loading • Constant amplitude. non-proportional loading • Non-constant amplitude. U V PATEL COLLEGE OF ENGINEERING  Page 91  . non-proportional loading In the above descriptions. proportionality. the amplitude identifier is readily understood. then the If the principal stress cannot be axes do not change. describes whether the changing load causes the principal stress axes to change. proportional loading • Non-constant amplitude. with the load ratio changing with time? The second identifier. Loading is of constant amplitude because only one set of FE stress results along with a loading ratio is required to calculate the alternating and mean values. Constant amplitude. There are essentially four classes of fatigue loading. axes do change. “back of the envelope” calculation describing whether the load has a constant maximum value or continually varies with time. with the ANSYS Fatigue Module currently supporting the first three: • Constant amplitude. which is analyzed with calculations for a single stress state. If the principal stress cycles counted simply and it is non-proportional loading. then it is proportional loading. Proportional Loading Constant amplitude. proportional loading is the classic. Is the loading a variant of a sine wave with a single load ratio or does the loading vary perhaps erratically.e+006 cycles Types of Cyclic Loading Unlike static stress.  Stress Component Life Units Equivalent (Von Mises) Units Name 1 cycle is equal to cycles 1. fatigue damage occurs when stress at a point changes over time.

Likewise. In constant amplitude loading. a load ratio of -1) and zero-based (apply a load then remove it. the U V PATEL COLLEGE OF ENGINEERING  Page 92  . since there are only two loadings. Common types of constant amplitude loading are fully reversed (apply a load. looking at a single set of FE results can identify critical fatigue locations. Loading is proportional since only one set of FE results are needed (principal stress axes do not change over time). no cycle counting or cumulative damage calculations need to be done. a load ratio of 0). Since loading is proportional. FIGURE Model > Static Structural > Solution > goodman stress life rl Value of Infinite Life Another available option when conducting a variable amplitude fatigue analysis is the ability to set the value used for infinite life.  The loading ratio is defined as the ratio of the second load to the first load (LR = L2/L1). if the alternating stress is lower than the lowest alternating stress on the fatigue curve. then apply an equal and opposite load.

However. cycles with very small alternating stresses may be present and may incorrectly predict too much damage if the number of the small stress cycles is high enough. but the first damage matrix was calculated with an infinite life if 1e6 cycles and the second was calculated with an infinite life of 1e9 cycles. The rainflow and damage matrices shown in Figure 13 illustrates the possible effects of infinite life. Both damage matrices came from the same loading (and thus same rainflow matrix).e+009 cycles U V PATEL COLLEGE OF ENGINEERING  Page 93  . the user can set the infinite life value that will be used if the alternating stress is beyond the limit of the SN curve. To help control this. FIGURE Model > Static Structural > Solution > goodman stress life rl TABLE Model > Static Structural > Solution > goodman stress life rl > Results Object Name Life State Scope Damage Safety Factor Equivalent Alternating Stress Solved Geometry Definition All Bodies Type Design Life Life Damage Safety Factor Equivalent Alternating Stress 1. This provides for an added level of safety because many materials do not exhibit an endurance limit. in non-constant amplitude loading. Setting a higher value will make small stress cycles less damaging if they occur many times.  fatigue tool will use the life at the last point. The rainflow and damage matrix results can be helpful in determining the effects of small stress cycles in your loading history.

2e-005 1/°C 2.3 7850.5e+008 Pa 2.e+011 Pa 0. Pa Thermal Thermal Conductivity Specific Heat Electromagnetics 60.6e+008 Pa Compressive Ultimate Strength 0.  Results Minimum Maximum Material Data 1.5e+008 Pa 4.e+012 cycles 1.7e-007 Ohm·m U V PATEL COLLEGE OF ENGINEERING  Page 94  .e-003 8.5 W/m·°C 434.4722e+007 Pa Structural Steel 2 TABLE Structural Steel 2 > Constants Structural Young's Modulus Poisson's Ratio Density Thermal Expansion Tensile Yield Strength Compressive Yield Strength Tensile Ultimate Strength 2. J/kg·°C Relative Permeability Resistivity 10000 1.7782 Pa 6.895 4. kg/m³ 1.

  FIGURE Structural Steel 2 > Alternating Stress TABLE Structural Steel 2 > Alternating Stress > Property Attributes Interpolation Log-Log Mean Curve Type Mean Stress U V PATEL COLLEGE OF ENGINEERING  Page 95  .

e+006 8.41e+008 2. 200.62e+008 2. 100. Cycles Cycles 10.62e+007 FIGURE Structural Steel 2 > Strain-Life Parameters U V PATEL COLLEGE OF ENGINEERING  Page 96  .896e+009 1. 2000.  TABLE Structural Steel 2 > Alternating Stress > Alternating Stress vs.069e+009 4.14e+008 1.e+005 1.e+005 1.999e+009 2.413e+009 1.827e+009 1. 10000 20000 Alternating Stress Pa 3.38e+008 2. 20. 50.14e+008 1.

e+009 Cyclic Strain Hardening Exponent 0.2 U V PATEL COLLEGE OF ENGINEERING  Page 97  .2e+008 -0.213 -0.  TABLE Structural Steel 2 > Strain-Life Parameters > Property Attributes Display Curve Type Strain-Life TABLE Structural Steel 2 > Strain-Life Parameters > Strain-Life Parameters Strength Coefficient Pa Strength Exponent Ductility Coefficient Ductility Exponent Cyclic Strength Coefficient Pa 9.47 1.106 0.

File Table 2. Solution Table 5. Physics Table Table 4.  Wind analysis Contents 1. User Figure Figure Figure 4 1 File 2 Mesh 3 Domain 4 Boundary 5 Boundary Information Information Physics Physics Flows for for for for for Report windanalysiscfx11_001 Report windanalysiscfx11_001 Report windanalysiscfx11_001 windanalysiscfx11_001 Report windanalysiscfx11_001 Data 2 3 Fig: Wind analysis U V PATEL COLLEGE OF ENGINEERING  Page 98  . Mesh Table 3.

File Report Table 1.  1.res 15 March 2008 03:46:08 PM CFX5 Air at 25 C None None File Version 11.0 Figure 2. File Information for windanalysiscfx11_001 Case File Path File Date File Time File Type Fluids Solids Particles windanalysiscfx11_001 D:/pressurevesselanalysis/windanalysiscfx11_001. pressure distributation on face of vessel U V PATEL COLLEGE OF ENGINEERING  Page 99  .

Mesh Report Table 2. streamline and pressure representation U V PATEL COLLEGE OF ENGINEERING  Page 100  . Mesh Information for windanalysiscfx11_001 Domain pressurevessel Nodes 7338 Elements 28308 Figure 3.  2.

  3.1 [m] Fractional Intensity = 0.4 Outlet Symmetry Wall Wall Wall U V PATEL COLLEGE OF ENGINEERING  Page 101  . Domain Physics for windanalysiscfx11_001 Name Location Type Materials Models pressurevessel B4 Heat Transfer Model = Isothermal Turbulence Model = SST Fluid Air at 25 C Turbulent Wall Functions = Automatic Buoyancy Model = Non Buoyant Domain Motion = Stationary Table 4. Physics Report Table 3. Boundary Physics for windanalysiscfx11_001 Domain Name Location Type Settings Flow Regime = Subsonic Normal Speed = 47 [m s^-1] Mass And Momentum = Normal Speed Eddy Length Scale = 0. F45.05 Turbulence = Intensity and Length Scale Flow Regime = Subsonic Mass And Momentum = Static Pressure Relative Pressure = 0 [Pa] Wall Influence On Flow = No Slip Wall Influence On Flow = Free Slip Wall Influence On Flow = No Slip pressurevessel inlet inlet Inlet pressurevessel outlet pressurevessel symp pressurevessel body pressurevessel freewalls pressurevessel pressurevessel Default outlet symp body freewalls F41.4.

7405e+02 -5.3776e+01 0.0000e+00 Boundary 1.0000e+00 8. Solution Report Table 5.1811e-07 -8.0000e+00 Boundary 0.  4.5229e+03 1.0000e+00 By interpolation we get: for 41 m/s of wind speed the wind pressure is 730 N/ m2 and from the standard wind load table we compare the result which is very accurate. U V PATEL COLLEGE OF ENGINEERING  Page 102  .1929e+03 0.7405e+02 1.0000e+00 Boundary 0.5579e-06 -1.4953e+02 0.8922e+03 Boundary -1.3129e+01 Boundary 0.0000e+00 -2.0000e+00 pressurevessel Default Boundary 0.3151e+00 8.9325e-02 5.0000e+00 -1.7605e+02 -1.5967e+01 0. Boundary Flows for windanalysiscfx11_001 Location body freewalls inlet outlet symp Type Mass Flow Momentum X Y Z -8.4447e+01 1.7561e+03 2.

U V PATEL COLLEGE OF ENGINEERING  Page 103  . Pfaudler began investigating new approaches in glass development that would lead to a glass composition that could be made available to all users of glass-lined equipment. because of the expansion of the chemical process and pharmaceutical industries world-wide and increased concerns for safety and quality control.  INTRODUCTION TO GLASS LINING Introduction of Glass lining (Glasteel) In recent years.

Pfaudler established the criteria for a new composition: A non-crystalline structure. regardless of where their processing operations are located. nonadherence and heat transfer efficiency. U V PATEL COLLEGE OF ENGINEERING  Page 104  .  Together with the chemical process industry and with the co-operation of Pfaudler divisions around the world. Now GMM Pfaudler customers. especially when ionised. However. thereby greatly extending its usage range. offering an unmatched combination of corrosion resistance. these are very recipe sensitive and general statements cannot usually be made. SiO. Increased resistance to acid and alkali corrosion. High resistance to impact. It has also been shown that colloidal silica additions to recipes containing the highly corrosive fluorine ion (F-) can drastically reduce the corrosive rate. Pfaudler's first "international glass". e. The result is Glasteel 9100®. thermal shock resistance.g. glass. can purchase a single glass system and be assured of getting the same high quality worldwide. An exception to this are chemistries that involve the element silicon (Si). Relatively small amounts of dissolved SiO can be highly effective in reducing the corrosion rate of the Glasteel 9100 system. A formulation that could be easily produced by all Pfaudler manufacturing plants. Si. impact strength. GMM Pfaudler sets a standard the world can depend on. With Glasteel 9100 ®. High resistance to thermally induced stresses.

corrosion rate increases. But because this water is an unbuffered. e.  Water Pure Water Pure water in the liquid phase is not very aggressive. Alkalis As alkali concentration rises. may reduce it. e. the influence of the nature and amount of other dissolved substances and agitation. the temperature gradient for alkaline glass corrosion.g.g. The corrosion rate of concentrated alkaline solutions cannot be expressed by the pH value alone. The result is that concentrated alkalis require a more definite setting of the temperature limits. Carbonates and phosphates usually increase the rate while alcohols and some ionic species. Also. pH-unstable system.g. salt solutions. At 170°C. Zn2+ Ca2+. Glasteel 9100 ® is highly resistant to condensing water vapour. to counter the possible danger of the condensate shifting to an alkaline pH. hydrochloric or acetic acid. tap water. A13+. Agueous Neutral pHMedia With these type media. is steeper. It is also highly recommended that the unjacketed top head be insulated or heat traced to reduce condensation formation. U V PATEL COLLEGE OF ENGINEERING  Page 105  . it is recommended that the vessel contents be slightly acidified with a volatile acid. corrosion rate depends greatly on the type and quantity of the dissolved substance. e. Other factors affecting alkaline corrosion are the specific reaction and the dissolving ability of the chemical. If there is a shift toward higher pH values. a corrosion rate of 0. the particular concentration must also be considered to establish appropriate operating temperatures. However. the isocorrosion curves for diluted alkaline solutions have to be consulted for orientation purposes. even a slight alkalization can change the situation.1 mm/year can be expected. Its behaviour resembles highly diluted acid and corrodes only the surface layer of the glass ("ion exchange process"). For aqueous solutions of alkaline materials with a pH value of 14.

2. Provides increased operating safety margin through its enhanced thermal protection. it is proven that the testing equipment does not have an inhibiting effect. Provides extended thermal shock protection for faster heating and cooling. Is ideal for the higher temperatures required by today's chemical process applications. sodium carbonate and ammonia take into account technically relevant parameters influencing the rate of corrosion. procedures are carried out in polypropylene bottles. the volume/ surface area ratio. such as product velocity and splash zone. inhibition effects by calcium ions. To eliminate the influence of the testing equipment on the rate of corrosion. 3. autoclaves with PTFE inserts were used. alkaline concentration and temperature. Provides potential for reduced cycle time compared to conventional vessel glass. even very slight contamination (tap water in sodium hydroxide. Due to these interactive complexities. for example) can cause major changes in the rate of corrosion. Under actual operating conditions. 5. meaningful testing is strongly advised. By comparing the results with control experiments. Pfaudler Ultra-Glas 6500 ® 1 . Allows safe and easy handling of high temperature processes never before approved for Glasteel equipment. For solutions above the boiling point. 6. Extends the range of Glasteel® applications. Other factors. for example. can affect the corrosion rate as well. 4.  Isocorrosion curves for sodium hydroxide. U V PATEL COLLEGE OF ENGINEERING  Page 106  . potassium hydroxide.

CAUTION: "Safe" operating temperatures vary with conditions. Type 4300 Glass Coatings Type 4300 ® glass coatings represent a new aspect of this tradition and are designed to bridge a perceived gap in the application range. Type 4300 glass coatings are advisable wherever alkaline conditions prevail during the U V PATEL COLLEGE OF ENGINEERING  Page 107  . operation below the maximum and above the minimum is recommended. GMM Pfaudler Type 4300 ® glass is still an acidic type of glass. Contact Pfaudler for details. Technical details of corrosion rates in common chemicals and thermal operation limits are available on request. These changes permit trouble-free application of the required high-stress coating and provide the highly corrosive-resistant glass-lined surface for which Pfaudler has been respected for years. Temperature Limits Although Ultra-Glas 6500 ® has a high degree of helpful compressive stress in the glass layer there are definite limits to the level of thermal stress which the glass can withstand without incurring damage: Only two thermal conditions must be considered when determining the temperature limits: A. Where in practical. altered applications and firing procedures. as well as changes in equipment design and materials of construction.  The features of GMM Pfaudler Ultra-Glas 6500 ® are the result of changes in glass composition and material preparation. B. but its primary application is based on improved alkali resistance. Because so many variables are involved. Introduction of media into a jacket. Introduction of media into a vessel. temperature ranges are given only as a guide.

Compared to our world renowned standard glass. Type 4300 ® has three times better alkali resistance. Inadequate redox stability of the vessel material in the alkaline range. technically relevant parameters influencing the rate of corrosion (for example. or where concentration and/or temperature conditions exceed permissible limits for conventional glass. Corrosion Resistance For pure acids and bases most commonly used in the chemical industry .  cycle. it is not recommended for aggressive acid conditions. the volume/surface area ratio. In practical operation these materials are always encountered with liquid additives. Type 4300 ® glass coatings are advisable where any of the following conditions exist: Protection of alkaline products against metal contamination. inhibition effects. under otherwise equal conditions. The Need For PPG U V PATEL COLLEGE OF ENGINEERING  Page 108  . Stabilization of high-molecular alkalis sensitive to metal contact. We therefore recommend performing corrosion tests or contacting a Pfaudler consultant to assure material suitability for individual processes. Danger of discoloration of alkaline products due to incorporation of metals. or that. or as a result of concentration and temperature. concentration. dissolved substances or gases which may have positive or negative effects on resistance. In addition. This means that higher process temperatures can be used. Although it is adequate for mild service. The Type 4300 ® glass does make a slight concession in the area of acid resistance. and temperature) are considered. these glass coatings will have three times the life expectations.

In light of the survey. the need for a different glass was evident. U V PATEL COLLEGE OF ENGINEERING  Page 109  . in context of the stringent requirements of GMP and FDA.  When the requirements of the Bulk Drug industry were studied recently. The process equipment of the chemical and pharmaceutical industries has so far been very similar . Two of the requirements of the pharmaceutical industry are increased purity in order to comply with the FDA and GMP requirements and alternating alkali/acid operation. vitamins and fine chemicals. Pfaudler's response was a novel glass tailored to the needs of manufacturing pharmaceutical products.especially in terms of glasslined reactors and components.

  Appendix U V PATEL COLLEGE OF ENGINEERING  Page 110  .

  U V PATEL COLLEGE OF ENGINEERING  Page 111  .

  U V PATEL COLLEGE OF ENGINEERING  Page 112  .

  U V PATEL COLLEGE OF ENGINEERING  Page 113  .

  BIBLOGRAPHY Dennis Moss Hiadri Farzdak C.0 U V PATEL COLLEGE OF ENGINEERING  Page 114  .S Sharma Somnath chatopadhay For Ansys : Tutorials of cfx 11.