vessel fabrication manual .pdf
TRANSCRIPT
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 1/49
Fa brica t ion a nd WeldingBasic Principles of Fabricated
Component Design:Manufacture and Test Methods
(Higher)
5794
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 2/49
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 3/49
September 1999
Fa brica t ion a ndWelding
B a sic P rinciples of Fa brica t ed
Component Design :Ma nufa ct ure a nd Test Met hods
(Higher)
S upport Ma t eria ls
HIGHER STILL
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 4/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,
Manufacture and Test Methods (Higher) - Teacher/Lecturer Information1
CONTENTS
LECTURERS / TEACHERS INFORMATION AND SUPPORT MATERIAL
Section Content
Section 1 The learning outcomes to be covered in the unit
Section 2 Teaching and learning advice
Section 3 Assessment procedures detailing what is to be assessed, when it
is to be assessed and method of recording results
Section 4 Resource Requirements including course notes book lists and
audio-visual list.
Section 5 Health and Safety
Section 6 Acknowledgements
STUDENTS INFORMATION AND SUPPORT MATERIAL
Section Contents
Section 1 The outcomes to be covered in the unit
Section 2 The assessment instruments for the outcome
Section 3 Students guide to working on this unit
Section 4 Course notes, technical information sheets and tutorials.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 5/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,
Manufacture and Test Methods (Higher) - Teacher/Lecturer Information2
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 6/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,
Manufacture and Test Methods (Higher) - Teacher/Lecturer Information3
SECTION 1 : OUTCOMES
The outcomes to be covered in the unit
Outcome 1
Interpret fabrication drawings, identify and interpret welding symbols.
Performance criteria
a. Interpretation of welding symbols is correct in terms of manufacturers’
instructions and relevant standards.
b. Interpretation of fabrication drawings is correct in terms of manufacturers’
instructions.
Range statement
Welding symbols: butt welds, filler welds, resistance welds, welding process, weld
location, weld details (contour, dimension, pitch, site instructions).
Fabrication drawings: assembly instructions, forming instructions, dimensions,
conventions, general information.
Evidence requirements
Graphic and written/oral evidence to demonstrate that the student can identify and
interpret common welding symbols.
Graphic and written exercises to demonstrate that the student can interpret simple
fabrication drawings according to manufacturers’ instructions, including details
identified in the range statement.
Outcome 2
Illustrate the factors affecting the design of fabricated components.
Performance criteria
a. Explanation of the factors affecting the structural integrity of design is accurate in
terms of the component.
b. Explanation of the factors affecting the functional aspect of design is correct in
terms of the component.
c. Illustration of the interrelationship among structural, functional and manufacturing
aspects of the fabricated component design are clear and accurate.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 7/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
4
Range statement
Components: tanks, drums, pressure vessels
Structural integrity: structural stiffening, shape, change of shape, added stiffness.
Functional: external service environment, internal service environment.
Evidence requirements
Written and/or pictorial evidence that the student clearly understands the difference
between the structural and the functional aspects of design and of the methods used toadd rigidity and/or stiffness to the container.
Written and/or pictorial evidence that the student can select a container that
incorporates the structural, functional and manufacturing aspects of design and
annotates the pictorial evidence accordingly.
Supplementary oral evidence to ensure that the student can cover the range.
Outcome 3
Describe the manufacturing methods used for a fabricated component.
Performance criteria
a. Description of the advantages and limitations of the methods used for componentmanufacture is comprehensive, clear and accurate.
b. Identification of the equipment and the sequence of manufacturing methods used
for a component are correct.
c. Completion of a flowchart is correct in terms of the given specification.
d. Explanation of the reasons why continuous testing is carried out on fabricated
components as they are being manufactured is clear, comprehensive and accurate.
Range statement
Components: tanks, drums, pressure vessels, structures.
Manufacturing methods: cutting, forming, jointing, handling, finishing.
Continuous testing: stage inspection, material checking.
Evidence requirements
Written and/or pictorial evidence that the student clearly understands the
manufacturing methods in use for container construction together with their relativeadvantages and disadvantages.
Performance evidence that the student can produce a flow-chart and specify the
appropriate methods in the correct sequence.
Written and/or pictorial evidence that the student can explain testing and the reasons
for choice of methods.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 8/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
5
Outcome 4
Describe inspection and test procedures used during and after manufacture of
fabricated components.
Performance criteria
a. Description of pressure tests and associated safety regulations is comprehensive,clear and accurate.
b. Specification of functional dimensions used in a dimensional test is correct.
Range statement
Tests: pneumatic, hydraulic,
Functional dimensions: tolerances, component size.
Evidence requirements
Describe inspection and test procedures used during and after manufacture of
fabricated components.
Performance evidence that the student can mark from given drawings the functional
dimensions of the component.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 9/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
6
SECTION 2 : TEACHING AND LEARNING ADVICE
Teaching Methods
Outcome 1 Main Topic
Interpretation of fabrication drawings and welding symbols.
Industrial drawings should be used as source for identification of symbols and
drawing interpretation, with constant reference to BSEN 22553 Welded, brazed and
soldered joints-Symbolic representation on drawings: 1995 (BS 499 part 2 ) The
coverage of welding symbols should concentrate on the identification and
interpretation of the weld symbol and not focus on the actual drawing of the symbol
Outcome 2 Main Topic
Design principlesElements of fabricated component design and their interrelationship. Use should be
made of good examples of functional design such as a pressed steel car wheel, fuel
containers, car radiator, liquid food containers with radiused corners. The design of bridges and gantries should be discussed. Sheets of paper, or cardboard can be
utilised to show the effects of poor design. Holes, both round and square in card, can
be used to demonstrate material failure by simple tearing and observing where the
tearing starts.
The context in which the design is taught should be limited to functional aspects such
as size shape strength etc and interrelationships between the design of the component
and the manufacturing methods.
Outcome 3 Main Topic
Manufacturing methods
Support sheets giving cutting, forming, jointing and finishing processes together with
worksheets on handling costs comparisons between the various processes should be
used. Flowcharts based on the use of scale models to show the operation layouts. A
selection of exemplar layouts can be used to help with teaching operation sequences
and process choice.
Works visits should be arranged to enhance student experience.
Hands on student activities and support materials can and should be used where
possible.
It should be the lecturer / teachers aim to constantly apply the outcomes to practical
situations to enable students to constantly apply underpinning knowledge themselves.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 10/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
7
Outcome 4 Main Topic
Quality assurance
Awareness of the variety of tests that a component may be subjected to during and
after manufacture. Workshop activities to demonstrate simple leak tests and low
pressure testing of containers.
Teaching Plan
The teaching plan below gives guidance on suggested teaching order and guidance on
the timing of assessment.
LEARNING
ACTIVITY
UNIT CONTENT
Interpret fabrication drawings, identify and interpret welding symbols
(O 1)
Lecturer input Drawing interpretation: drawing principles – projection methods,identification of welding symbols, use of BSEN 22553: 1995
Formative assessment (O 1)
Practical
exercise/tutorial
Interpret industrial drawings and manufacturer instructions, identify weld
symbols on industrial type drawings
Assessment Assessment (O 1)
Illustrate the factors affecting the design of fabricated components (O2)
Lecturer input Design principles: structural integrity, functional aspects, and environmental
requirements.
Practical activities Show the effects of poor design by the use of card or paper. Demonstratematerial failure by simple tearing and observing where the tearing starts
around square and round holes.
Assessment (O 2)
Describe the manufacturing methods used for a fabricated component
(O3)
Lecturer input Manufacturing operations: operational sequences, manufacturing methods,
flowcharts, equipment, continuous testing, inspection methods and materialchecking
Formative assessment (O3)
Practical activity Produce operational sequence sheets, design flowcharts for manufacture.
Assessment (O3)
Describe inspection and test procedures used during and after
manufacture of fabricated components (Lo4)
Lecturer input Quality assurance: inspection and testing methods, dimensional checks, leak
testing.
Workshop activity Conduct simple leak test, carry out dimensional checks.
Assessment (O4)
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 11/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
8
SECTION 3: ASSESSMENT PROCEDURES
Assessment procedures detailing what is to be assessed, when it is to be assessed
and method of recording results
Outcome 1
The assessment should ensure that students can identify weld symbols and interpret
drawings and manufacturers instructions. This section can be integrated with thesection on planning and manufacturing sequences and an integrated assessment is
possible.
A combined identification and interpretation exercise should be used to cover the
range and performance criteria (a). For example, the assessment could be in the form
of a table that contains welding symbols. Students should complete the table
alternating between identifying a symbol from a sketch to sketching a symbol from a
description. All items in the range should be covered.
Alternatively, students can also sketch the weld joint as identified by the symbol.
Drawing interpretation should be based on a series of questions relating to features
found on fabrication drawings.
Outcome 2
The assessment should be mainly a combination of written and graphical exercises.
The student should be able to understand functional and manufacturing aspects of design. This could be assessed by the use of a written exercise based on the factors
affecting the design of a fabricated component, combined with structured questions,formulated around a sketch/drawing of a fabricated structure.
Outcome 3
The assessment of this outcome could be organised so that an assignment or project
forms the backbone where the design parameters of a container are assessed.
Manufacturing processes, process flowcharts and manufacturing instructions are
required for the manufacture of a fabricated component and finally the integration of
testing methods are considered to ensure that the design criteria have been complied
with during manufacture. Hands-on student activities and support material should beused wherever possible. It should be the teacher or lecturer’s aim to constantly relate
the outcomes to practical situations.
Outcome 4
Written exercises in the form of inspection reports could be used to evidence that the
student can explain testing methods produce sequence of testing operations and
justifying their use. The identification of functional dimensions of a component can
be achieved by the annotation of sketches or integrated with outcomes 2 and 3.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 12/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
9
Assessment Timing
Assessments should be carried out under closed book conditions. It is difficult to
allocate a time scale to each outcome assessment, as it is possible to carry out the
assessment as teaching and learning progresses. A notional timescale for the average
student to complete the assessment is given in the table below.
Assessment Procedures
OUTCOME NUMBER APPROXIMATE TIME ALLOCATION
1 60 minutes
2 60 minutes
3 70 minutes
4 40 minutes
Retention of evidence
All written work should be retained for verification purposes.
Reassessment
Time is allowed within units for the assessment and reassessment of outcomes.
Where a student has not attained the standard necessary to pass a particular outcome
or outcomes, there should be an opportunity to be reassessed. It is not necessary toreassess the students on all questions provided the lecturer / teacher is
satisfied that the students overall performance is satisfactory. Reassessmentinstruments should be designed to ensure the same degree of rigor. Alternative
fabricated components, weld symbols and sketches can be used for the purposes of
reassessment.
Recording Procedures
Student achievement can be recorded using the sample sheets that follow. As anoutcome is achieved it can be ticked and any relevant comments entered if required on
the Record of Assessment Checklist.
The Record of Performance sheet can be used to record information on assessment
schedules and deadlines including reassessment dates if applicable.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 13/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
10
RECORD OF ASSESSMENT
AND
OBSERVATION CHECKLIST
BASIC PRINCIPLES OF FABRICATED COMPONENT DESIGN,MANUFACTURE AND TEST METHODS
Class: _____________________________
Date: _____________________________
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 14/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
11
RECORD OF ASSESSMENT / CHECKLIST
NAME LO 1 LO 2 LO 3 LO 4 COMMENTS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 15/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
12
STUDENTS RECORD OF
PERFORMANCE
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 16/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
13
RECORD OF STUDENT NAME
PERFORMANCE CLASS:
Topic Date Due/
Week Number
Achieved/
Not Achieved
Comments Date Completed
Lecturer / Teacher Name:
Lecturer / Teacher Signature:
Date:
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 17/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
14
SECTION 4 : RESOURCES
Resource Requirements including course notes, book list and audio-visual list.
Course notesCourse notes are included as examples of the type of information that should be given
to students.
Recommended Book List
TITLE PUBLISHER AUTHOR
Which Process? Abington ISBN 1855730081 Houldcroft, P.
Welding Processes and
Technology
Pitman ISBN 0273411551 Romans, D. and Simons, E.N.
Welding Processes Cambridge ISBN 05021215307 Houldcroft, P.
Technician Fabrication &Welding 1
Cassell Ltd ISBN 0304300276 Cooper, K. J. and Greenwood,T. P.
Welding and Fabrication
Technology
Pitman ISBN 0273015060 Kenyon, W.
Basic Welding and Fabrication Pitman ISBN 0273013211 Kenyon, W.
Blueprint Reading for Welders Delmar ISBN 0827329970 Bennett, A. E. and Siy, L. J.
Basic Engineering Drawing Longman Scientific &
Technical ISBN 0582988551
Rhodes, R. S. and Cook, L. B.
Welding and Metal Fabrication
Journals
The Welding Institute The Welding Institute
Engineering Design forTechnicians
Pitman Hawkes, B and Abinett, R
The Engineering Design Process Pitman ISBN 0 273 01895 7 Hawkes, B and Abinett, R
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 18/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
15
Recommended Video list
TITLE SOURCE
Aluminium – Gas Metal Arc Welding Murex
Aluminium – Gas Tungsten Arc Welding Murex
Basic Skills – Gas Metal Arc Welding Murex
Basic Skills - Gas Metal Arc Welding Murex
Conducting Welder Approval Tests The Welding Institute
Cores for Satisfaction Murex
Facts of NDT The Welding Institute
Process and Practice – Gas Tungsten Arc Welding Murex
Process and Practice – Gas Metal Arc Welding Murex
Safe Electric – Arc Cutting and Welding Murex
Safe Oxy Acetylene Cutting and Welding Murex
Stainless Steel - Gas Metal Arc Welding Murex
Stainless Steel - Gas Tungsten Arc Welding Murex
Thermal Joining BBC Education
College Teaching/Learning pack
UNIT NUMBER TITLE SOURCE
2570012 Manufacture of Containers Anniesland College
2570012 Manufacture of Containers Motherwell College
Key Resources and workshop facilities
• industrial drawings
• assignment sheets, planning sheets
• a selection of components highlighting design features
• low pressure leak testing equipment (small pump)
• industrial visits.
• access to fabrication and welding workshops
• current British/European standards (details in the table below)
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 19/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
16
British/European standards
NUMBER TITLE
BSEN 22553 : 1995 (BS 499 part 2 ) Welded, brazed and soldered joints-Symbolic representation
on drawings
Current Standards
The use of current British and European standards is required throughout the course.
It is recommended that users contact the British Standards office for information on
current standards in use. the contact address is listed below.
British Standards OfficeQuality House
2000 Academy Park Gower Street
Glasgow
G51 1PP
TEL: 0141 427 2825 (Customer service 01819967000)
Technical information sources
The journal Connect from the Welding Institute includes a series entitled Job
Knowledge for Welders which will provide information on materials used in the
fabrication and welding industry.
The journal is published by TWI Abington Hall, Cambridge CB1 6AL, Telephone
0223 891162, FAX 0223 892588.
The articles contained in the journal can be freely reproduced as long asacknowledgement is made to The Welding Institute.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 20/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
17
SECTION 5: HEALTH AND SAFETY
The safety of teaching / lecturing staff and students working in the fabrication and
welding workshops must be the primary concern of everyone involved.
This has to take precedence over all other activities and be sustained against allother pressures.
There are many aspects to safety as follows:
• Statutory requirements
• Centre procedures
• Centre structure
• Staff training and behaviour
• Workshop/laboratory features
• Student training and behaviour
It is beyond the scope of this document to provide details of all of these items, which
should be embraced as part of centre safety policy. Lecturers / Teachers must,however, be satisfied that all appropriate safety measures are in place before
embarking on work within the fabrication and welding workshops.
Student training is a recurrent activity which is likely to be the direct responsibility of
the Lecturer / Teacher. While this has to take place on a continuous basis as work in
the workshop/laboratory proceeds, it is helpful to perform specific safety training at
course commencement. Such training might form part of the course induction as its
relevance extends across all course units. This is particularly important for fabricationand welding students, as they should be encouraged to develop their own safety
culture, which should become a lifelong asset.
There is a rich diversity of material available on the subject but as a minimumstudents should have access to the booklet Be Safe available from the local LEC as
part of the skillseekers programme. The large welding companies such as Murex and
The Welding Institute provide excellent Health and Safety materials.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 21/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) - Teacher/Lecturer Information
18
SECTION 6: ACKNOWLEDGEMENTS
We gratefully acknowledge the support and assistance provided by colleagues at
Motherwell College, Kilmarnock College, Falkirk College, Perth College and
Anniesland College who have contributed material and helpful advice for this pack.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 22/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
1
STUDENT INFORMATION AND SUPPORT MATERIAL
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 23/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
2
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 24/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
3
SECTION 1: OUTCOMES
The outcomes to be covered in the unit
Outcome 1
Interpret fabrication drawings, identify and interpret welding symbols.
Performance criteria
a. Interpretation of welding symbols is correct in terms of manufacturers’
instructions and relevant standards.
b. Interpretation of fabrication drawings is correct in terms of manufacturers’
instructions.
Range statement
Welding symbols: butt welds, filler welds, resistance welds, welding process, weld
location, weld details (contour, dimension, pitch, site instructions).Fabrication drawings: assembly instructions, forming instructions, dimensions,
conventions, general information.
Evidence requirements
Graphic and written/oral evidence to demonstrate that the student can identify and
interpret common welding symbols.
Graphic and written exercises to demonstrate that the student can interpret simple
fabrication drawings according to manufacturers’ instructions, including details
identified in the range statement.
Outcome 2
Illustrate the factors affecting the design of fabricated components.
Performance criteria
a. Explanation of the factors affecting the structural integrity of design is accurate in
terms of the component.
b. Explanation of the factors affecting the functional aspect of design is correct in
terms of the component.
c. Illustration of the interrelationship among structural, functional and manufacturing
aspects of the fabricated component design are clear and accurate.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 25/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
4
Range statement
Components: tanks, drums, pressure vessels
Structural integrity: structural stiffening, shape, change of shape, added stiffness.
Functional: external service environment, internal service environment.
Evidence requirements
Written and/or pictorial evidence that the student clearly understands the difference
between the structural and the functional aspects of design and of the methods used toadd rigidity and/or stiffness to the container.
Written and/or pictorial evidence that the student can select a container, which
incorporates the structural, functional, and manufacturing aspects of design and
annotates the pictorial evidence accordingly.
Supplementary oral evidence to ensure that the student can cover the range.
Outcome 3
Describe the manufacturing methods used for a fabricated component.
Performance criteria
a. Description of the advantages and limitations of the methods used for componentmanufacture is comprehensive, clear and accurate.
b. Identification of the equipment and the sequence of manufacturing methods used
for a component are correct.
c. Completion of a flowchart is correct in terms of the given specification.
d. Explanation of the reasons why continuous testing is carried out on fabricated
components as they are being manufactured is clear, comprehensive and accurate.
Range statement
Components: tanks, drums, pressure vessels, structures.
Manufacturing methods: cutting, forming, jointing, handling, and finishing.
Continuous testing: stage inspection, material checking.
Evidence requirements
Written and/or pictorial evidence that the student clearly understands the
manufacturing methods in use for container construction together with their relativeadvantages and disadvantages.
Performance evidence that the student can produce a flow-chart and specify the
appropriate methods in the correct sequence.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 26/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
5
Outcome 4
Describe inspection and test procedures used during and after manufacture of
fabricated components.
Performance criteria
a. Description of pressure tests and associated safety regulations is comprehensive,clear and accurate.
b. Specification of functional dimensions used in a dimensional test is correct.
Range statement
Tests: pneumatic, hydraulic.
Functional dimensions: tolerances, component size.
Evidence requirements
Performance evidence that the student can mark from given drawings the functional
dimensions of the component.
Written and/or pictorial evidence that the student can explain testing and the reasons
for choice of methods.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 27/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
6
SECTION 2: ASSESSMENT
The assessment instruments for the outcome
This unit covers:
• interpretation of fabrication drawings and the identification of weld symbols
• factors affecting the design of fabricated components
• manufacturing methods used for the fabrication of components
• quality assurance methods
Outcome 1
Outcome 1 will be assessed by the use of written questions.
You will be required to identify a welding symbol from a given sketch or sketch a
weld joint from a given symbol.
You will be required to identify the weld symbols as given on a drawing of afabricated component.
Drawing interpretation question where you are required to identify various aspects
from a fabricated component drawing.
Outcome 2
Outcome 2 will be assessed by the use of written questions.
You will be required to state examples for each of the following aspects of fabricated
design:1. Structural
2. Functional
3. Manufacturing
You will be required to answer questions relating to the design aspects of for a given
fabricated component.
Outcome 3
Outcome 3 will be assessed by the use of written questions.
You will be required to complete a planning operations sheet for the manufacture of afabricated component or, to include details of the processes and equipment required.
You will be required to give written details related to the inspection and testing of acomponent detailed in a previous question.
Outcome 4
Outcome 4 will be assessed by the use of written questions.
You will be required to explain the processes and procedures required in the testing of
the fabricated component detailed in the assessment for Outcome 2.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 28/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
7
SECTION 3: STUDENT GUIDE
In this unit you will be introduced to Basic Principles of Fabricated Component
Design, Manufacture and Test Methods. This will include the principles associated
with the manufacture of pressure vessels and simple structures together with the
associated quality assurance processes and techniques.
An essential part of the unit will be the topic on interpretation of drawings and
identification of weld symbols in accordance with the new British and Europeanstandards (BSEN).
As far as possible practical exercises based on design and manufacture will be used as
the teaching method. The quality assurance topic will include you being involved in
the testing of a fabricated component and reporting on subsequent defects.
You will also have the opportunity to plan a sequence of operations for the
manufacture of a fabricated component.
Prior knowledge
You will not require any prior knowledge of fabricated component design in order to
undertake this unit.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 29/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
8
SECTION 4: COURSE NOTES AND TUTORIALS
Welding Symbols
Details of symbols
Details of symbols used in fabrication and welding drawings can be found in BSEN
22553: 1995 Welded, brazed and soldered joints – Symbolic representation on
drawings.
Position of symbol on drawing
The welding symbol consists of the following components (see Figure 1):
• Arrow line (a)
• Reference line (b)
• Identification line (c)
• Welding symbol
(b) (d)
(a)
(c)
Joint
Figure 1
Position of the reference line
The reference line shall preferably be drawn parallel to the bottom edge of the
drawing. If this is not possible it should be drawn perpendicular (see figure 2).
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 30/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
9
Position of the arrow line
The position of the arrow line with respect to the weld is of no special significance
(see figure 2). The arrow line shall:
• Join one end of the continuous reference line such that it forms an angle
with it
• Be completed by an arrow head.
Figure 2
Position of symbol with regard to the reference line
The symbol is placed either above or beneath the reference line, in accordance with
the following regulation:
• The symbol is placed on the continuous side of the reference line if the weld
(weld face) is on the arrow side (see figure 3a)
• The symbol is placed on the dashed line side if the weld (weld face) is on
the other side of the joint (see figure 3c)
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 31/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
10
Figures 3a, b and c
The distinction between ‘arrow side’ and ‘other side’ is detailed in Figure 3b.
For symmetrical welds only
To be welded on the arrow side
Figure 3a
Other Arrow Arrow Other
Side side side side
Weld on arrow side Weld on other side
Figure 3b
To be welded on the other side
Figure 3b
Note:
More detailed information is available from the standard including elementary
symbols, combined symbols, supplementary symbols, dimensioning of welds and
indication of welding process (in accordance with ISO 4063).
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 32/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
11
Fabrication Processes
The main processes used in the manufacture of fabricated components are as follows:
• Design
• Marking out
• Cutting
• Forming
• Joining
• Assembly and Inspection
Marking out
Where small quantities only are required or one-off jobs, it is usual to usual to use the
method of direct marking from the drawing. This entails working from set datum
points which may be squared lines on plates or square edges.
TemplatesIf set shapes, rolling diameters or angles have to be formed then use is made of ‘set
templates’. The use of a set template is shown in figure 1a.
If a large number of items have to be produced then a template is used (see figure 1b).
Templates are made from wood, special card like paper or metal depending on the
number and type of object. The cost of making the template is justified if large
batches have to be produced. It is important that, after marking out, critical
dimensions are checked by a competent person before drilling, etc., to avoid any delay
and expense which would occur due to mistakes. Care should be taken in planning
the marking out of a number of components from a single sheet, to achieve economy
of material.
The position of holes can be pre marked through the template but these should then be
marked using a centre punch or nipple punch. To help with identification, dab marks
can be circled with white paint.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 33/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
12
Figure 1a Figure 1b
Marking-off large plates
Large plates have to be marked off in the flat position or on ‘the floor’. A datum line
is used and this is scribed adjacent to one edge with the aid of a straight edge and
scriber. An alternative method of marking out a straight line on a large plate is by theuse of a chalkline (see figure 2). The procedure for using a chalkline is as follows:
1. The line is located on the plate
2. The chalked line is stretched and ‘flicked’ on to the plate3. The line is then marked (chalked) on the plate
Note:
An engineers square can be used to ensure the line is pulled up in a straight line from
the plate.
T E M P L A T E
SET TEMPLATE
5 1 m
m
T E M P L A T E
USE OF TEMPLATE
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 34/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
13
The use of a chalkline
S T E E L P L A T E
C H A L K L I N E
M A G N E T T R Y - S Q U A R E
Figure 2
Metal cutting
The two main methods used to cut plate material are as follows:• Thermal cutting
• Shearing
Thermal cutting
Thermal cutting can be by the oxy-fuel method or plasma. In oxy-fuel cutting the fuel
gas can be propane or acetylene. Propane is cheaper than acetylene and requires a
special cutting nozzle.
The process works by the principle of rapid oxidation. When carbon steel is heated to
a temperature of approximately 850°C the iron in the steel ‘burns’ in the presence of the oxygen and oxides are formed. At this stage a chemical reaction takes place. This
is called an exothermic reaction, which in turn produces more heat, which melts the
oxides that have been formed and the molten oxide is blown away. The equipment
consists of gas supply and accessories, cutting torch and suitable cutting nozzle.
Cutting nozzle
A cutting nozzle consisting of an outer nozzle, which supplies a mixture of gasses inthe form of a pre-heating flame and an inner nozzle that supplies the blast of cutting
oxygen. A selection of nozzle types is shown in figure 3a.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 35/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
14
Hand cutting torch
The most common type is a high pressure torch which is made up of a mixing
chamber containing the combined gasses and a tube section carrying the cutting
oxygen to the nozzle (figure 3b). The cutting oxygen is released on to the workpiece
by a lever on the top of the torch. Accurate cutting of standard shapes can made by
the use of a selection of cutting aids (figure 4 ).
Factors influencing the quality of cut
A good quality cut depends on the following:
• Correct nozzle size for plate thickness
• Correct gas pressures
• Correct cutting speed
• Correct nozzle distance from plate
• Good operator technique
If all these factors are present then a smooth cut edge is produced. This cut edge iscalled the ‘Kerf ’.
The effects of variation in flame cutting procedures can be seen in figure 5.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 36/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
15
Figure 3
Cutting Nozzles
A B C D E
A O N E - P I E C E C U T T I N G N O Z Z L E - P A R A L L E L B O R E , 3 - 9 P R E - H E A T H O L E S , N O S K I R T.
B T W O - P IE C E C U T T I N G N O Z Z L E - V E N T U R I B O R E , P R E - H E A T A N N U L U S , N O S K I R T.
C T W O - P I E C E N O Z Z L E - V E N T U R I B O R E , P R E - H E A T F L U T E S , L O N G S K I R T.
D T W O - P I E C E N O Z Z L E - P A R A L L E L B O R E , P R E - H E A T S L O T S , L O N G S K I R T.
E T W O - P I E C E N O Z Z L E - P - A R A L L E L B O R E , P R E - H E A T F L U T E S , O X Y G E N C U R T A IN .
ACETYLENE
ACETYLENE
NATURAL GAS
PROPANE
PROPANE
NOZZLE DESIGN FEATURES
Figure 3a
Cutting Torch
90O
E N S U R E E D G E O F P L A T E
R E M O V E R U S T & S C A L EB E F O R E C O M M E N C I N G
F U E L G A S
F U E L G A SVALVE
H E A T IN G O X Y G E NVALVE
C U T T I N G O X Y G E NC O N T R O L L E V E R
HEATINGO X Y G E N
CUTTINGO X Y G E N
MAINTAINC O R R E C TDISTANCE
MIXER IN
H E A DA D J U S T P R E S S U R E S
CORRE CTLY ATR E G U L A R S
Figure 3b
Figure 4
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 37/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
16
Cutting aids and attachments
CUTTING BEVEL
60O
S E L E C T N O Z Z L E & P R E S S U R E S
F O R I N C R E A S E D T H I C K N E S S
O F B E V E L
B L O W P I P E S T E A D I E D A N D
C U T T I N G A N G L E M A I N T A IN E D
U S I N G T W O S U I TA B L E
S T R A I G H T B A R S
BEVAL ATTACHMENT
A D J U S T A B L E R A D I U S B A R
P O I N T F I TS P U N C H M A R K
A T C I R C L E C E N T R E
R O L L E R C A R R I E S B L O W P I P E
R A D I U S B A R F I T S O N
B L O W P I P E H E A D
LARGE CIRCLE CUTTING
30O
CUTTING BEVELLED EDGE ON INCLINE
RADIUS BAR
SMALL CIRCLE GUIDE
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 38/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
17
Figure 5
Types of Edge Produced – Flame cutting faults
Description Edge condition
Good cut, all settings correct
Rounded top edge due to melting, scale
forming, gouging and drag lines at
pronounced bottom edge, brittle bottomedge, scale difficult to remove.
Cause:
• Travel speed too slow
Undercut edge, drag lines excessive, topand bottom edge rounded.
Cause:
• Travel speed too fast
Melted and rounded top edge, undercuton edge caused by oxygen strumming out
of nozzle, bottom edge square.
Cause:
• Nozzle distance from workpiece too
great.
Rounded top edge, heavy beading
evident, appearance of cut edge otherwise
good.
Cause:
• Nozzle height incorrect
Edge has a regular bead, wide kerf at thetop of edge with undercut beneath.
Cause:
• Cutting oxygen pressure too great.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 39/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
18
Rounded and melted top edge, slag
adhering to edge, taper face.
Cause:
• Pre-heat flame too large.
Shearing
The most common form of shearing is by the use of a guillotine. There are four main
types of guillotine:
• Hand operated lever - bench type shear
• Foot operated - treadle type
• Electric power driven
• Hydraulic power
Hand operated lever type guillotines and treadle guillotines are used to cut sheet metal
up to 1.6mm thick. Power operated guillotines are used in thick plate work usually up
to 12mm thick.
Treadle and power guillotines are fitted with front guides and back gauge/stops, on
some machines these are set electrically (figure 6).
Safety
Safety guards are fitted to guillotines to protect the operator from the cutting blade,these can be adjusted mechanically.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 40/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
19
Figure 6
Cutting set up adjustable back stop
STARTING
LEVER
EMERGENCYSTOP
FIXED S ID ES T O P
CUTTING LINE
TOP BLADE
LOWER BLADE
CLAMPING RAM
PLATE
TOP BLADE
LOWER BLADE
ADJUSTABLE
BACK STOP
CLAMP
Rolling and bending
Bending rolls are used to produce cylindrical forms. Bending rolls can be hand
operated for sheet metal use or power operated for thick plate work. In the main rolls
are horizontal but in some cases they can be vertical when forming of large plate is
required. As a rule of thumb the minimum diameter that can be rolled is twice the rolldiameter.
Roll types
The most common roll types are pinch and pyramid (figure 7). Pinch type rolls are
used for forming sheet metal
Pyramid type rolls are used for heavy plate forming and as the name suggests the rolls
are arranged in the form of a pyramid. The top roll is adjusted up and down and can
be partly detached to allow the work to be removed.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 41/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
20
Pre-forming
The design of rolling machines does not allow the leading and trailing edges to be
formed therefore it is necessary to pre-form the plate prior to rolling to ensure the
leading and trailing plate edges are curved. This can be achieved by bending on a
press, using the rolls themselves or in the case of sheet metal hand formed with a
mallet. The curve can be checked using a set template.
Figure 7
Roll types
Pyramid type Pinch type
Bending
Sheet metal is bent using folding machines. The three main steps in folding are asfollows:
1. Clamping – in clamping, the material is pressed between a lever-operated top
clamping blade and the folding beam.
2. Folding – in folding, the bottom folding beam is pulled up causing the work to
bend
3. Removal of the work – care must be taken when folding to ensure that the work
can be removed from the machine. Planning should be carried out prior to
folding and a folding sequence should be established.
These steps are detailed in figure 8.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 42/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
21
Figure 8
Folding stages
FO L D IN G - S TA N D A R D B E D B A R
B E N D IN G - S M A L L R A D IU S
R E V E R S E B E N D S
25 .4mm
M A X R A D I U S
U S E O F ‘ R A D IU S F IN G E R S ’
Bending Thick Plate
Thick plate is bent by using a press brake. Press brakes come in two forms,mechanical and electro-hydraulic. A press brake is really a wide ram press, and can
be used for various types of work. It consists of a top tool and a bottom dye. Press
brakes can be up-stroking and down-stroking. In up-stroking a ram pushes the bottom
tool up to meet the top fixed tool. Hydraulic press brakes are usually up-stroking
types. In down-stroking the ram brings the top tool down to meet the bottom fixed
tool. Examples of tooling can be seen in figure 9.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 43/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
22
Figure 9
Press brake tooling
M A X D E P T H O F B O
X
1 2 3 1 2 3
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 44/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
23
Joining
The most common joining method used in fabrication is welding. Details of common
welding processes can be found in the tables below.
PROCESS DESCRIPTION APPLICATION
Manual
Metal Arc
An arc is formed between a flux-coated
electrode and the joint to welded,causing the joint edges and theelectrode end to melt. Molten filler is
transferred across the arc into themolten weld pool where both fusetogether to form a welded joint
protected during cooling by a layer of slag. Very high quality welds may beproduced.
Welding of structural steelwork. New and
repair work
Hard-facing applications
Boilers, ships, pressure vessels, bridges,
container tanks.
Metal ArcGasShielded
The power source is normally a d.c.Rectifier with the torch connected tothe positive pole. A filler wire iscontinuously fed through the torch
from a wire reel. The welding arc isself-adjusted by the machine. Ashielding gas is also passed through the
torch to the workpiece. The current isadjusted by varying the wire feedspeed. The most common forms of
MAGS welding are Dip transfer, usedon thin sheet and Spray transfer usedon heavy plate.
Widely used in the fabrication industry.
Structural steel work, shipbuilding, car bodyrepair, stainless steel fabrications,aluminium work, pipe work
TungstenArc GasShield
The arc is struck between a non-consumable tungsten electrode bymeans of an H.F. spark and theworkpiece.
A suitable gas shield is introduced into
the weld pool protecting the weld poolfrom atmospheric contamination.
The current can be AC or DC
depending on the material to be weldedor the welding operation. AC is
preferred for the welding of aluminiumand magnesium alloys.
High quality welding of ferrous and non-ferrous metals Thin sheet materials.
Root runs in pipes used in oil productionwork.
Food processing equipment.
Car industry.
High precision production work.
Repair work on non-ferrous materials.
Aircraft industry.
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 45/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
24
Fabrication Design
Stiffening of fabricated components:
A thin sheet metal plate will not support a heavy load, however a thick metal plate of
the same cross sectional area will. It may be part of the design process that the
component has to be light in weight but strong enough to support a load. In this casethe thin sheet must be stiffened to make it rigid and strong. An example of stiffening
can be demonstrated by using simple card (figure 10a).
Figure 10a
Principle of stiffening
P A P E R TH I C K N E S S
P A P E R
TH I C K N E S S
A R E A O F H I G H S TR E S S
A R E A O F H I G H S TR E S S
N E U TR A L A X I S
N E U TR A L A X I S
TU M B LE R O F W A TE R
E M P T Y T U M B L E R S
N O TE P A P E R
O R I G I N A L P A P E R
C O R R U G A TE D
B Y FO LD I N G
Building in ri gidity
A simple method of imparting rigidity to a structure is by forming a flange on the
ends of the plate or by forming a safe edge (figure 10 b). In cylindrical work the
introduction of dome shapes or curves help with stiffening. The swaging of a
cylindrical shape container can add rigidity and it also adds to the aestheticappearance of the object. (Figure 10 c).
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 46/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
25
Bolted, welded or riveted stiffeners
Large panel sections can be made more rigid by the use of applied stiffeners such as
top hat sections, angle sections, heavy plate flat bar and D shaped bar. These
stiffeners can be spot welded, tack welded, bolted or riveted to the panels (figure 10d).
Angle frames can also be used to support fabricated structures.
It is also possible to impart rigidity to a sheet metal structure such as ducting, by
introducing a ‘diamond break fold’ to the component. This also helps minimise
‘drumming’ in sections of sheet metal ducting, due to vibration from extractor fanmotors. (figure 10 e)
Figure 10 b
Edge Flanging and Safe Edges
Figure 10c
Curved surfaces and swaging
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 47/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
26
Figure 10 (continued)
Figure 10d
Applied stiffeners
TOP HAT SECTIONE D G E S F O L D E D
F L A T B A R
S T I F F E N E R
D - S H A P E D B A R
S T I F F E N E R
A N G L E I R O N
S T I F F E N E R
R I V E T
Figure 10e
Angle Frames and Diamond Folding
ANGL E IRON
ST IF F ENER
RIVET
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 48/49
Fabrication and Welding: Basic Principles of Fabricated Component Design,Manufacture and Test Methods (Higher) – Student Materials
27
Assembly and Inspection
Figure 11 gives details of the inspection methods used to check a pressure vessel for,
alignment (plumb line), squareness (set square), dimensional accuracy (straight edge
and tape measure) and straightness (tensioned wire).
Figure 11
Inspection methods
=
=
T O P V E S S E L
B O T T O M V E S S E L
T O P S U P P O R T
B O T T O M S U P P O R T
T I M B E R S U P P O R T F O R P L U M B L I N E
PIPE
F L A N G E S
P U L L E Y
W E I G H T
P L A T FO R M B R A C K E T S A L I G N E D
U S I N G T E N S I O N E D W I R EP L A T F O R M
S U P P O R T
B R A C K E T S
BULK LIQUID
VESSEL
7/28/2019 vessel fabrication manual .pdf
http://slidepdf.com/reader/full/vessel-fabrication-manual-pdf 49/49