UNIVERSITI TEKNIKAL MALAYSIA MELAKA
Design, Analysis and Fabrication of Pressure
Vessel
Thesis submitted in accordance with the partial requirements of the
Universiti Teknikal Malaysia Melaka for the
Bachelor of Manufacturing Engineering (Manufacturing Process)
BY
b
Affendi b. Hussin @ Cholan
Faculty of Manufacturing Engineering
March 2008
ABSTRACT
This bachelor degree final project presents design, analysis and manufacturing of
pressure vessel. In the design of pressure vessel safety is the primary consideration,
due the potential impact of possible accident. There have a few main factors to
design the safe pressure vessel. This writing is focusing on analyzing the safety
parameter for allowable working pressure. Allowable working pressures are
calculated by using PV Elite which comply with the ASME VIII, Rules of
construction pressure vessel div 1. The corruption of the vessel are probability occur
at maximum pressure which is the element that only can sustain that pressure. At the
end of this project, a pressure vessel which is air receiver are fabricated and the
procedure of manufacture are explained clearly.
ABSTRAK
Projek akhir sarjana muda ini mempersembahkan rekabentuk, analisis dan proses
pembuatan pengandung tekanan. Di dalam aspek rekabentuk pengandung tekanan,
perkara yg perlu dititik beratkan ialah keselamatan disebabkan keupayaan berlakunye
kemalangan besar. Terdapat banyak factor yang yang perlu diambil kira dalam
mereka bentuk pengandung tekanan. Di dalam penulisan ini hanya memfokuskan
analisis terhadap had tekanan yang dibenarkan ketika pengandung tekanan
beroperasi. Tekanan yang dibenarkan dikira dengan menggunakan PV Elite, sebuah
perisian yang memenuhi kod peraturan membuat pengandung tekanan, ASME VIII.
Kemunglunan kerosakan yang berlaku disebabkan elemen-elemen yang terdapat
pada pengandung tekanan yang tidak dapat menampung had tekanan maksimum. Di
akhir projek ini, salah satu jenis pengandung tekanan dibuat iaitu penerima udara dan
prosedur pembuatan diterangkan dengan jelas.
CHAPTER 1
INTRODUCTION
1.1 Overview of Pressure Vessel
Tanks, vessel and pipelines that carry, store or receive fluids are called pressure vessel.
A pressure vessel is defined as a container with a pressure differential between inside
and outside. The inside pressure is usually higher than the outside. The fluid inside the
vessel may undergo a change in state as in the case of steam boiler or may combine with
other reagent as in the case of chemical reactor. Pressure vessel often has a combination
of high pressure together with high temperature and in some cases flammable fluids or
highly radioactive material. Because of such hazards it is imperative that the design be
such that no leakage can occur. In addition vessel has to be design carefully to cope with
the operating temperature and pressure.
Pressure vessel are used in a number of industries; for example, the power generation
industry for fossil and nuclear power, the petrochemical industry for storing and
processing crude petroleum oil in tank farms as well as storing gasoline in service
station, and the chemical industry. Their use has expanded throughout the world.
Pressure vessel and tank are in fact essential to the chemical, petroleum, petrochemical
and nuclear industry. It is in the class of equipment that the reaction, separation and
storage of raw material occur. In the same word, pressurized equipment is required for a
wide range of industrial plant for storage and manufacturing purpose.
pressure vessels are usually spherical or cylindrical with dome end. The cylindrical
vessels are generally preferred because of they present simple manufacturing problem
and make better use of the available space. Boiler, heat exchanger, chemical reactor and
so on, are generally cylindrical. Spherical vessels have the advantages of requiring
thinner walls for a given pressure and diameter than the equivalent cylinder. Therefore
they are used for large gas or liquids container, containment buildings for nuclear plant
and so on.
In the design of pressure vessel safety is the primary consideration, especially for
nuclear reactor vessels, due the potential impact of a possible accident. In generally
however, the design is a compromise between consideration of economics and safety.
The possible risks of a given failure and its consequent are balanced against the effort
required for its prevention; the resulting design should achieve an adequate standard of
safety at minimum cost.
Figure 1.0: Pressure Vessel
1.2 Problem Statement
Vessel failures can be grouped into four major categories, which describe why a vessel
failure occurs. Failures can also be grouped into types of failures, which describe how
the failure occurs. Each failure has a why and how to its history. It may have failed
through corrosion fatigue because the wrong material was selected! The designer must
be as familiar with categories and types of failure as with categories and types of stress
and loadings. Ultimately they are all related.
Material- Improper selection of material; defects in material.
Design- Incorrect design data; inaccurate or incorrect design methods;
inadequate shop testing.
Fabrication- Poor quality control; improper or insufficient fabrication procedures
including welding; heat treatment or forming methods.
1.3 Objectives
The purpose of this project is to study the implementation and practices of pressure
vessel designs. The objectives of this project are:
To identify the pressure vessel
To analyze the safety parameters for allowable working pressure using PV Elite
which comply to ASME VIII standard.
To fabricate the pressure vessel as per the reference standards
1.4 Scope
To ensure the objective is achieved, some of the important elements must be
consideration. There is:
Research about pressure vessel
To analyze by using PV Elite at Akra Engineering Sdn Bhd.
This project will be collaborate with Akra Engineering Sdn Bhd to provide the
source and place to fabricate the pressure vessel.
Chapter 2
LITERATURE REVIEW
B.S. Azzam, M.A.A. Muhammad, M.O.A. Mokhtar et a1 (1996) was proposed a new
design technique that enables rapid and efficient design calculations. This design method
enables the designer of the composite pressure vessel to get readily the ultimate failure
pressure of these vessels depending on the number of reinforced layers, layer thickness,
fiber orientations, and materials. In this work a numerous of aluminum tubes have been
wrapped by different number of composite layers made from different fibrous materials
(glass, graphite and kevlar fibers). Then, these tubes have been used as pressure vessels
which tested till the explosion failure. A comparison between the results of the
experimental testing and the theoretical proposed design for these composite pressure
vessels has been presented. This comparison has shown a good agreement between the
theoretical and experimental analysis.
Shu-Ho Dai (1998) explain that the prediction of the occurrence of failure events for
pressure vessels used in the process industry is a newly developing technology in the
field of modern technical management of facilities. It is of great significance for
ensuring safe and high efficiency operations in modernized large-scale and high
parameter facilities of chemical, petrochemical, nuclear and electric power plants.
Changheui Jang et al. (1999) describes the pressure vessel integrity under a pressurized
thermal shock using transient histories such as temperature, pressure and heat transfer
coefficient, the stress distribution is calculated and then stress intensity factors are
obtained for a wide range of crack sizes. The stress intensity factors are compared with
the fracture toughness to check if cracking is expected to occur during the transient.
Critical crack depth diagrams are prepared for each transient which is expected to initiate
a pressurized thermal shock accident. Plant-specific analyses of the most limiting plant
in Korea are performed to assure the structural integrity of the reactor vessel and the
results are discussed.
Leta Y. Woo (1999) has mention that mild carbon steel with specification American
Society for Testing and Materials (ASTM) A285 is a common material of construction
for vessels in the petroleum and nuclear industries. Storage tanks were constructed
between 1951 and 1956 from hot rolled carbon steel plate specified as ASTM A285
Grade B. Extensive analyses and experimental investigations have demonstrated tank
integrity in full consideration of potential service induced degradation mechanisms,
including stress corrosion cracking.
Vu D.K. and Staat M. (2007) published limit load formulae for circumferential defects
overestimate the burst pressure for penetrating defects in pipes by the factor two in the
short crack limit, because they only consider axial stress. Therefore, a class of limit load
solution is discussed which takes the triaxial state of stress into account. The solutions
for pressure loaded crack faces are improved analytically. Primal-dual limit analysis
with the finite element method is used to adjust all solutions to numerical results. Limit
loads are obtained for circumferential cracks of all sizes in thick-walled cylinders.
Yoneda, Makoto et a1 (2004) explain about a high temperaturelhigh pressure vessel for
treating a workpiece placed in the interior of the vessel at a high temperature and a high
pressure, said vessel comprising: a cylindrical body, with piano wire wound under
tension round an outer periphery of said cylindrical body; and lid members which tightly
close axial openings of said cylindrical body so as to be disengageable from said
openings, said cylindrical body comprising: an inner cylinder; a plurality of spacers
arranged along an outer periphery surface of said inner cylinder; and an outer cylinder
fitted on said inner cylinder through said spacers, wherein cooling water flow paths are
formed each between adjacent said spacers, said cooling water flow paths extending
from one end side to an opposite end side of said cylindrical body.
Giglio M. (2003) comparing two different methods for the construction of pressure
vessel nozzles, designed with the same safety coefficient, according to ASME and VSR
1995 standards. It defines numerical and experimental analysis of behaviour under low-
cycle fatigue for pulsating pressure. In particular, a nozzle with integral reinforcement,
designed according to ASME standards, is compared to a nozzle with external
reinforcement (applied reinforcement plate) designed according to VSR 1995 standards
with the same safety coefficient. Strain gauge tests have been carried out on the plastic
behaviour of the two structures in order to evaluate the expected fatigue life based on
common criteria, using both the local strain and energetic approaches. At the same time,
a FEM model of the nozzle with plate has been used to calculate numerically the
expected fatigue life based on the same criteria. Finally, in order to identify the best
system to exploit for design, comparisons are made of the fatigue life predictions, which
are numerically and experimentally obtained and which are determined according to the
standards of the two nozzle types to identify the better system.
J. Lewinski (2002) presents the problem of stress concentration in a cylindrical pressure
vessel with ellipsoidal heads subject to internal pressure. At the line, where the
ellipsoidal head is adjacent to the circular cylindrical shell, a shear force and bending
moment occur, disturbing the membrane stress state in the vessel. The degree of stress
concentration depends on the ratio of thicknesses of both the adjacent parts of the shells
and on the relative convexity of the ellipsoidal head, with the range for radius-to-
thickness ratio between 75 and 125. The stress concentration was analytically described
and, afterwards, the effect of these values on the stress concentration ratio was
numerically examined. Results of the analysis are shown on charts.
J. schiedermaier (2004) explain about the economical and safe design of pressure
vessels requires, besides others, also a detailed knowledge of the vessel failure behavior
in the case of existing imperfections or cracks. The behavior of a cracked component
under a given loading situation depends on material toughness. For ferritic steels, the
material toughness is varying with temperature. At low temperature dominantly brittle
fracture behavior is observed, at high temperature the failure mode is dominantly ductile
fracture. The transition between these two extremes is floating.
D.H. Nash (2004) explain about the progress of pressure vessel technology over the
years has been influenced by many important events. This paper identifies a number of
milestones which have provided a stimulus to analysis methods, manufacturing,
operational processes and new pressure equipment. The formation of a milestone itself
along with its subsequent development is often critically dependent on the work of many
individuals. It is postulated that such developments takes place in cycles, namely, an
initial idea, followed sometimes by unexpected failures, which in turn stimulate analysis
or investigation, and when confidence is established, followed finally by the emergence
of codes ad standards. Starting from the industrial revolution, key milestones are traced
through to the present day and beyond.
Ugur Guven (2007) present regarding the failure pressures of thick and thin walled
cylindrical pressure vessels considering the Voce hardening law and plastic orthotropy
effect are obtained. The solution presented is used to compare the failure pressures of
copper and brass cylindrical pressure vessels.
Petrovic A. (2007) describe about the analysis of a cylindrical pressure vessel loaded by
axial and transverse force on the free end of a nozzle. The nozzle is placed such that the
axis of the nozzle does not cross the axis of the cylindrical shell. The method of finite
element was applied to determine the state of stress in the cylindrical shell. The value
obtained for stress in the nozzle region were used to determine the envelopes of
maximum stress values, maximum values on this envelopes and distances between
values on envelopes and the outer edge of a nozzle. The different between
stresses deduced from strain gauge readings on experimental and calculated stressed was
maximum of 12%.
Najmi M. and Jahrorni J. S.A. (2007) explain about the Cr-Mo steels which are widely
used for pressure vessels in refineries and petrochemical plants, have a potential for
hydrogen and temper embrittlement. During long-time service the embrittlement leads to
decrease of the critical flaw size of brittle fracture and/or to the reduction of the
remaining life of a pressure vessel. In this investigation the effect of high temperature
and high pressure hydrogen on a vessel, made of 3Cr-1Mo low-alloy steel is studied.
Inspections show that the only detected crack in the base metal is originally formed by
welding defects and calculations show that it will not grow up. Therefore, it is predicted
that the operation of the pressure vessel in normal condition and under regular
supervision can be continued.
Price J. W. H. and Kerezsi B. B. (2002) describe the use of the ASME and British
Standard codes to estimate the growth of cracks driven manly by thermal shocks.
Repeated application of the thermal shocks may lead to crack ignition and crack growth.
The ability to use current codes and standards to describe this type of crack growth is
desirable. Areas of large conservation in the methods currently used in industry are
identified and possible alternatives, less conservative approach are suggested. If the
methods are fully applied, the possibility of crack growth slowing can be captured and
the replacement of equipment with thermal shock cracking might be avoided.
Masuyama F. (2007) explain that creep-strength enhanced ferritic steels such as Gr.91,
Gr.92 and Gr.122 have been introduced for power plant applications recently, and some
have experienced creep failure in boiler tubes and thick wall components after several
years of operation. In order to use these steels safely in power plants, establishment of
creep life prediction and design factors for base metal and weldment is essential. In this
Paper, creep rupture strengths and lives obtained by means of uniaxial creep testing and
internal pressure component testing for the above-mentioned high-strength ferritic steels
are presented comparatively. Design life and weld reduction factors are discussed based
on the data and on ASME criteria for establishing allowable stresses in the time-
dependent temperature region.
Numerous boiler explosions took place through the late 1800s and early 1900s. This led
to the enactment of the first code for construction of steam boilers by the commonwealth
of Massachusetts in 1907. This subsequently results in the development and publication
of the ASME Boiler and Pressure Vessel code in 1914 to standardize the design,
manufacturing, and inspection of boiler and pressure vessel. The ASME and the ASTM
(American Society for Testing Material) material specification merged in 1924. The first
publication of section VIII 'unfired pressure vessel' appeared in 1925. The year 1928
saw the advance of welded pressure vessel. For higher pressure the welded shell were
made thicker than 70 mm. these required nondestructive examination (NDE) before
service. In 1934, a joint API-ASME Committee published the first edition of an unfired
pressure vessel code especially for the petroleum industry. In 1952 these two separate
code merged into a single code which is the ASME Unfired Pressure Vessel Code,
Section VIII. The ASME Pressure Vessel Code, Section VIII Division 2 "Alternative
Rules for Pressure Vessel "was published in 1968 and the original code became section
VIII Division 1:"Pressure Vessel".(Cepluch, R.J. pressure vessel technology, 114, 1992).
CHAPTER 3
METHODOLOGY
3.1 Overview
In this chapter, the selection of pressure vessel is described and the application of
selected pressure vessel is been explain. To design of pressure vessel the selection of
Code are important as a reference guide to achieve the safety pressure vessel. The
selections of ASME VIII div 1 are described. The standard of material use are
explains in this chapter. Beside of that, the design and analysis software to obtain the
result are introduced. Instead of that, design process methodology is also described.
The overall schedule and planning of this project are shown in figure 3.1 and figure
3.l.the sequential of the project also can be shown in figure 3.2. At the end of this
chapter the step of the fabrication process are shown.
lection
Shc SA 106 - .
meter Design r a n pressure (external and int nperature ( internal and e
3. Material type Diameter and Length
c rr,.4;.,m
Seamless Carwn steel Pipe
I calcularlon and Analysis
Fabrication F
on and Cutti1 mad ell
Head Shell Shell
Nou SA 106 Carbon
:le Gr B Steel
Figure 3.1 Flow Chart
3.2 Pressure Vessel Selection
There have many applications in pressure vessel in the industry. Air receiver was
selected as these projects are collaborating with Akra Engineering Sdn. Bhd.
(AESB). The design requirement are required according client requirement as
(AESB) are prepare the requirement. Air receiver is selected as pressure vessel
because of the widest application in industry. Air receiver acts as a reservoir for the
storage of compressed air and absorbs pulsations in the discharge line from the
compressor. A steady flow of air is thus provided to the service line. Any moisture or
oil present in the air as it carries over from after-coolers to the air receiver will be
separated out in there. Air receiver should therefore be placed in a clean and well-
ventilated location, and be set off the ground, on concrete blocks or on a suitable
foundation, as the dampness on the ground causes excessive rusting and corrosion
around the bottom. The bottom seams should be kept clean and well painted at all
times. Sufficient access to allow visual inspection must always be provided all
around the body of the receiver.
Both cylindrical shell and end plates are each, preferably, made from a single
plate. If the cylindrical shell and end plates cannot possibly be made from a single
plate, they shall be made with minimum number of joints and the longitudinal seams
in adjacent sections shall be as far as practicable. Longitudinal seams should not pass
through nozzles or openings. All welding should be carried out by welders who have
been tested according to the ASME Code.
Figure 3.2 Air receivers
3.3 Code Selection
There are many engineering standards which give information on the design,
and fittings of an air receiver. The ASME is normally followed in
Malaysia, but other national or international standards may also be used. For this
design, ASME VIII (division 1) "Construction of Pressure vessel Codes" are selected
according to above statement. It is, however, emphasized that any standard selected
for manufacture of the air receiver must be followed and complied with in entirety
and the design must not be based on provisions from different standards. In case of
any doubt, reference can be made to the Boilers and Pressure Vessels Division.
3.4 Material Selection
Several of materials have been use in pressure vessel fabrication. The selection of
material is base on the appropriateness of the design requirement. AU the materials
used in the manufacture of the receivers shall comply with the requirements of the
relevant design code, and be identifiable with mill sheets. The selection of materials
of the shell shall take into account the suitability of the materials with the maximum
working pressure and fabrication process. For this kind of pressure vessel, the
selection of material use is base on Appendix B:
Table 3.1: Part Material
According to ASTM standard this specification for pressure vessel is suitable for
higher temperature services. The chemical and tensile requirement of, Seamless
Carbon steel pipe for high temperature service (SA-106 B) is as per table 3.2 and
table 3.3
Head Shell Nozzle N3-Relieve Valve (RV)
NZPressure Gauge (PG) N4-Drain N1-Inlet N5-Outlet
Flanges (Slip on)
SA-234 WPB SA- 106 B SA- 106 B SA- 106 B SA- 106 B SA- 106 B SA- 106 B SA- 106 B
Table 3.2: Chemical Requirement of SA-106 B
Table 3.3: Tensile Requirement of SA-106 B p~
Carbon, max
Manganese
Phosphorus, max
Sulfur, max
Silicon, min
Chrome, max
Copper, max
Molybdenum, max
Nickel, max
Vanadium. max
Composition %, (Grade B)
0.3
0.29-1.06
0.035
0.035
0.10
0.40
0.40
0.15
0.40
0.08
The chemical and tensile requirement of, Piping fitting of wrought Carbon steel and
Alloy steel for moderate and high temperature service (SA-234 WPB) is as per table
3.4 and table 3.5
Table 3.4: Chemical Requirement of SA-234 WPB
Tensile strength, min, psi (MPa)
Yield strength, min, psi (MPa)
Grade B
60 000 (415)
35 000 (240)
Carbon, max
Manganese
Phosphorus, max
Sulfur, max
Silicon, min
Chrome, max
Copper, max
Composition %, (Grade B)
0.35
0.29-1.06
0.05
0.058
0.10
0.40
0.40
Table 3.5: Tensile Requirement of SA-234 WPB
Molybdenum, max
Nickel, max
Vanadium, max
Columbium, max
0.15
0.40
0.08
0.02
Tensile strength, min, psi (MPa)
Yield strength, min, psi (MPa)
Grade B
60 000-85 000 (415-585)
35 000 (240)
3.5 Design Software PV Elite is a comprehensive program for the complete structural design or analysis
of pressure vessels according to latest standards from ASME, PD 5500 (British
Code), API-579 and the Welding Research Council. PV Elite evaluates the entire
vessel, analyzing the effects of vessel deadweight and bending due to wind and
seismic loads. It combines these overall loads with pressure to design and check
vessel wall thickness. Basing stress calculations on this total structural load ensures
sufficient wall thickness for the vessel in its operating environment and ensures
proper design of the vessel supports. Element types include cylindrical shells;
elliptical, spherical, torispherical, conical and flat heads; conical sections (including
knuckles); body flanges; and skirts with base ring details. The program provides base
ring, saddle, leg and lug design and also includes modules for analyzing vessel
components such as nozzles, flanges, base ring and other vessel components. To
make the design process easy, the status bar constantly displays the position of the
current element, its required thickness, its maximum allowable working pressure and
its maximum allowable pressure in the new and cold condition. Graphic presentation
keeps your data organized and confirms the integrity of the model.
Building even complex vessel models in PV Elite is quick and easy. As each major
element is added, the graphical display is updated to show the new element in
relation to the others. This image confirms the content of the model. Clicking on the
element in the plot brings up the tabular data for that element. As details (such as
nozzles, insulation or trays) are added they too are illustrated, and clicking on them
will bring up their data for review. With a simply click on an icon, the component is
added to the vessel. This provides a logical and intuitive modeling of the vessel.
Vessels diameters can specified based on either ID or OD.
3.5.1 Design Codes and Standards Implemented
This software keeps pace with the development of vessel design codes and standards
by incorporating code changes and releasing product updates as these changes
become mandatory. The codes and standards implemented in PV Elite include:
ASME Code Section VIII, Division 1 & 2 - Rules for the
Construction of Pressure Vessels
ASMEIANSI B 16.5 - Pipe Flanges and Flanged Fittings
The program includes following databases:
Material properties- Including the Allowable Stress and Yield Stress
tables from ASME Sec. VIII, Divland Div 2, PD5500 and TEMA.
ANSI flange dimension database.
ANSI pipe schedule database.
3.5.2 Analysis Capabilities:
The integrated vessel module of PV Elite can perform both new design and re-rate of
an existing design. For new Vessel design, this program can quickly set required wall
thickness for heads, shells and cones, and size components for valid combinations of
pressure (internal and external), deadweight (erected, operating and hydrostatic test
conditions), user applied loads, and wind and seismic live loads. The program sums
the weights of each element and all its details to calculate the compressive stresses in
the vessel wall. The live loads tend to bend the vessel, creating both tensile and
compressive stresses in the vessel wall.' Pressure, too, causes either tensile or
compressive longitudinal stresses in the vessel wall. PV Elite combines these stresses
and adjusts the vessel wall on an element-by-element basis to ensure that this new
vessel meets the minimum requirements for both tension and compression. The
project will do by using PV Elite. Prior to running the software, the design input or
parameter had to be preparing first. The design inputs are mention in table 3.3
PV Elite has a component analysis module (also known as CodeCalc) and a complete
integrated vessel modeling module. Status bar displays important results for the
elements, such as required thickness and maximum allowable pressures, as well as
informational values such as design length and flange rating.
Figure 3.3 PV Elite software
Results are also displayed for the attachments like nozzle. Any failures are
highlighted in red color. This insures that you are always aware of how changes to a
design are affecting the vessel. Users can also view the analysis results from the
input view by opening the "Quick Calculation Screen ".There are options that can
speed-up the design process, such as automatic selection of wall thickness. Default
values for material, diameter, wall thickness, corrosion allowances, temperatures and
pressures can be set, these are used as a starting point for new models.
The program allows entering data in English, SI or any user-defined units. Using the
CreateIReview facility users can create their own units and then change units on fly.
The unique List Processor provides a concise method to review specific data sets, for
example all the nozzles in the model. The fields in the List Processor tables are
active, allowing modification of the data. Other features include toolbars that can be
positioned any way on the screen for optimum usability. The program documentation
is available in a hard copy and within the program in a portable document format
(PDF). h roba t Reader software is needed for viewing this included documentation.
3.6 Design Pressure
The pressure use in the design of a vessel is call design pressure. It is recommended
to design a vessel and its parts for a higher pressure than the operating pressure. A
design pressure higher than the operating pressure with 10 percent, whichever is the
greater, will satisfy the requirement. The pressure of the fluid will also be
considering. The maximum allowable working pressure (MAWP) for a vessel is the
permissible pressure at the top of the vessel in its normal operating
position at a specific temperature. This pressure is based on calculations for every
element of the vessel using nominal thicknesses exclusive of corrosion allowance. It
is the basis for establishing the set pressures of any pressure-relieving devices
protecting the vessel. The design pressure may be substituted if the MAWP is not
calculated. (UG22, ASME VIII.)
Table 3.6: Design Input
3.7 Design temperature
Design temperature is the temperature that will be maintained in the metal of the part
of the vessel being considered for the specified operation of the vessel. For most
vessels, it is the temperature that corresponds to the design pressure. However, there
is a maximum design temperature and a minimum design temperature (MDMT) for
any given vessel. The MDMT shall be the lowest temperature expected in service or
the lowest allowable temperature as calculated for the individual parts. Design
temperature for vessels under external pressure shall not exceed the maximum
temperatures
Code preference Internal Design Temperature Internal Design Pressure External Design Temperature External Design Pressure Diameter Vessel Design Length, Tangent to Tangent Material thickness Corrosion Allowance Joint Efficiency , E
3.8 Corrosion Allowance
Corrosion occurring over the life of a vessel is catered for by a corrosion allowance,
the design value of which depends upon the vessel duty and the corrosiveness of its
ASME VII div 1 50 C 1000.00 KPa 50 C 103.42 KPa 219.10 mm 589.60 mm 8.18 mm 0.00 0.711.0
content. A design criterion of corrosion allowance is 1 mm for air receiver in which
rnndensation of air moisture is expected. (ASME KW).
3.9 Engineering Drawing
Draw~ng actual size r 1 dimension style (s&l
Dimension drawing ir A ayout arran
Figure 3.4 Engineering drawing flow chart
After design are prepared the shape of pressure vessel are sketch in paper. In this
sketch the dimension are very important before drawing by AutoCAD. The
procedure of engineering drawing is follow by drawing by AutoCAD. . All
components and parts were placed according to actual size and location / orientation.
It called Model Drawing. Drawings are in 2D orthographic type. Layers are set with
different colors to differentiate the lines.
Figure 3.5 AutoCAD 2D orthographic
Dimension Style is for dimensioning several drawing with has different scales. This
is because the actual scale is too large to put all the drawing in one drawing paper.
Usually a drawing will have more than one scale but the dimensioning will be the
same size due to dimensioning style. When drawing has finished, it will be
dimensioned for fabrication purposes. The dimension Style will be selected
according to the specific drawing scale. Layout Arrangement is a process to place
drawing onto drawing paper layout with title block. The approval of engineering
drawing is important before submit to the fabrication process. For the result in next
chapter the full of engineering drawing by AutoCAD are been prepared.
CHAPTER 4
MANUFACTURE PROCEDURE
4.1 Overview
In this chapter, the manufacturing of pressure vessel is described and the application of
selected pressure vessel is been explain. The figures in the chapter show the fabrication
process of pressure vessel.
4.2 Fabrication
4.2.1 Material receiving
This part is the material control stage. All material arrived should be verify and identify
to ensure it is a right material ordered from supplier which is comply with the
requirement. This can be done with reviewing mill certificate. The condition of material
also have been verify such as surface defect, dimension, diameter and thickness. If the
material not meet the requirement or the quantity is not adequate it should return to
supplier for replacement. Figure 4.1 to Figure 4.7 show the material use in the fabrication
process.
Figure 4.1 Material
4.2.2 Material inspection
Figure 4.2 Nozzle 318 inch inspection