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