Met2014 ridle christopher

ASME Demonstrator Pressure Vessel
A Baccalaureate thesis submitted to the
Department of Mechanical and Materials Engineering
College of Engineering and Applied Science
University of Cincinnati
in partial fulfillment of the
requirements for the degree of
Bachelor of Science
in Mechanical Engineering Technology
by
Christopher Ridle
April 2014
Thesis Advisor:
Professor Janak Dave, Ph.D.

ASME Demonstrator Pressure Vessel Christopher Ridle
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ACKNOWLEDGEMENTS
My father, William Ridle, has been my inspiration to pursue a career in engineering. His
knowledge in all facets of engineering is impressive, but his mastery of fluid dynamics and
pressurized equipment is exceptional. He presented this design opportunity to me, and I am
grateful that he offered the challenge.
Professor Janak Dave has served as my academic guide through this endeavor. His
experience in industry applied directly to the design and fabrication of the vessel.
Jennifer Ridle, my beautiful wife, and I made it through a very challenging time
together. Her father passed shortly after the start of this project. This coincided with the
beginning of a challenging semester. The additional trials required to support each other and
the family nearly caused us to put our academic pursuits on hold for another semester or
year. It was through her strength and perseverance that we were able to find our way through
that difficult time without delaying or abandoning our academic pursuits.
Specialty Piping Corporation of Davisville, West Virginia provided an excellent but
unexpected partner in this endeavor. A mutually beneficial relationship was formed in which
they received a code compliant design and calculations at no cost. I received the vessel once
they no longer needed it. They also allowed me to observe their Joint Review which was a
valuable learning experience. Special thanks goes to the Quality Control Manager, Steve
Zoller. He was my point of contact, and he was always available to answer questions and
share his knowledge.
John Groh of American Muscle Street Rods and Classics plus Dean Brown of the
Little Miami Golf Center assisted with testing.

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TABLE OF CONTENTS
ACKNOWLEDGEMENTS...................................................................................................... 1
TABLE OF CONTENTS.......................................................................................................... 2
LIST OF FIGURES .................................................................................................................. 3
LIST OF TABLES.................................................................................................................... 4
ABSTRACT.............................................................................................................................. 5
INTRODUCTION AND RESEARCH..................................................................................... 6
PROBLEM STATEMENT.................................................................................................................................... 6
RESEARCH ..................................................................................................................................................... 7
INTERVIEWS................................................................................................................................................. 11
CUSTOMER SUPPLIED INFORMATION .......................................................................... 12
SURVEY AND RESULTS................................................................................................................................. 12
PROCESSING SURVEY RESULTS.................................................................................................................... 14
PRODUCT OBJECTIVES ..................................................................................................... 15
DESIGN.................................................................................................................................. 17
DESIGN ALTERNATIVES ............................................................................................................................... 17
DESIGN SELECTION...................................................................................................................................... 21
SHELL ......................................................................................................................................................... 22
HEADS ........................................................................................................................................................ 23
NOZZLES ..................................................................................................................................................... 25
WELDS ........................................................................................................................................................ 27
ADDITIONAL COMPONENTS ......................................................................................................................... 29
FINAL DESIGN ............................................................................................................................................. 31
PRESSURE LOADING ANALYSIS..................................................................................... 33
ASME ANALYSIS ........................................................................................................................................ 33
SUPPLEMENTARY ANALYSIS ........................................................................................................................ 35
COMPARING ANALYSES............................................................................................................................... 36
FABRICATION, JOINT REVIEW & TESTING .................................................................. 37
FABRICATION .............................................................................................................................................. 37
JOINT REVIEW ............................................................................................................................................. 43
TESTING ...................................................................................................................................................... 46
SCHEDULE AND BUDGET................................................................................................. 48
SCHEDULE................................................................................................................................................... 48
BUDGET ...................................................................................................................................................... 49
CONCLUSION....................................................................................................................... 50
WORKS CITED ..................................................................................................................... 52
APPENDIX A – RESEARCH................................................................................................ 54
APPENDIX B – SURVEY RESULTS................................................................................... 59
APPENDIX C – QUALITY FUNCTION DEPLOYMENT (QFD) ...................................... 60

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APPENDIX D – PRODUCT OBJECTIVES.......................................................................... 61
APPENDIX E – SCHEDULE AND BUDGET...................................................................... 62
APPENDIX F – BILL OF MATERIALS............................................................................... 63
APPENDIX G – PROOF OF DESIGN .................................................................................. 64
APPENDIX H – COMPONENT DRAWINGS ..................................................................... 65
APPENDIX I – MATERIAL REFERENCE VALUES ......................................................... 73
APPENDIX J – ASME CALCULATIONS ........................................................................... 75
APPENDIX K – SUPPLEMENTAL CALCULATIONS...................................................... 83
APPENDIX L – COMPARING ANALYSES ....................................................................... 85
APPENDIX M – JOINT REVIEW CHECKLIST.................................................................. 86
LIST OF FIGURES
Figure 1 – Steel pipe marked for identification. (4) 7
Figure 2 – Design calculation example (Shell Thickness). (8) 8
Figure 3 – Demonstration vessel. (8) 9
Figure 4 – Petrochemical storage tank. (1) 10
Figure 5 – Refinery vessel. (1) 10
Figure 6 – Rectangular pressure vessel for use in an effluent treatment plant. (11) 17
Figure 7 – Spherical pressure vessels for the storage of liquid natural gas. (12) 18
Figure 8 – Liner-less composite pressure vessel for FASTRAC 1 satellite. (13) 18
Figure 9 – SolidWorks rendering of composite pressure vessel. 19
Figure 10 – SolidWorks rendering of a spherical vessel produced from sections. 19
Figure 11 – Hemispherical head cap. (14) 20
Figure 12 –Hemispherical caps joined to produce a pressure vessel. 20
Figure 13 – Flat head. (17) 24
Figure 14 – Torispherical head. (17) 24
Figure 15 – Semi-elliptical head. (17) 24
Figure 16 – Hemispherical head. (18) 25
Figure 17 – Conical head. (17) 25
Figure 18 – One inch, 3000 lb.-rated, threaded coupling. 26
Figure 19 – Single-V butt-joint. (19) 27
Figure 20 – Beveled weld with strengthening fillet. (20) 28
Figure 21 – Gauge, ball valve and fittings for outlet nozzle. 30
Figure 22 – Ball valve and fitting for inlet nozzle. 30
Figure 23 – Decanter pressure vessel construction drawing. 31
Figure 24 – Components welded by SPC. 32
Figure 25 – Rendering of assembled vessel. 32
Figure 26 – Exploded view of vessel. 32
Figure 27 – Pressure Retention Capabilities of Welded Components. 34
Figure 28 – Plot of interior stresses within shell. 35
Figure 29 – Pressure vessel after completion of welding. 38
Figure 30 – Alternate view of pressure vessel with all welds complete. 38

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Figure 31 – Specialty Piping Corporation’s fabrication shop. 38
Figure 32 – Example of a Specialty Piping Corporation process piping project. 38
Figure 33 – Ball valve, gauge, and fittings connections using PTFE tape. 39
Figure 34 – Maximum pressure and maximum temperature indicated in large lettering. 39
Figure 35 – Included for public display at the University of Cincinnati. 40
Figure 36 – Data plate with machined lettering. 40
Figure 37 – Data plate lettering accentuated with hobby paint. 41
Figure 38 – Prepared data plate adhesion surface. 41
Figure 39 – Completed Vessel (front). 42
Figure 40 – Completed Vessel (rear). 42
Figure 41 – Former ASME marking system example. (6) 43
Figure 42 – New ASME marking system example. (1) 44
Figure 43 – Pressure gauge during pressure test. 46
Figure 44 – Vessel heating using an acetylene torch. 47
Figure 45 – Temperature readings using a laser surface thermometer. 47
Figure 46 – Shell 65
Figure 47 – Head with cut-out for nozzle. 66
Figure 48 – 1 inch, 3000 pound rated H-coupling for use as nozzle. 67
Figure 49 – C-channel for use as data plate bracket. 68
Figure 50 – Data plate. 69
Figure 51 – Exploded view of Specialty Piping fabricated and joined components. 70
Figure 52 – Overall dimensions of vessel with fittings. 71
Figure 53 – Exploded view of vessel with bill of materials. 72
LIST OF TABLES
Table 1 – Scoring results from survey. 12
Table 2 – Relative Importance of Engineering Characteristics. 14
Table 3 – Pipe sizes available for use as shell. (16) 22
Table 4 – Schedule for vessel planning, fabrication, testing and presentation. 62
Table 5 – Bill of materials with component costs. 63
Table 6 – Material reference values for pressure vessel shell (SA-53). (7) 73
Table 7 – Material reference values for pressure vessel heads (SA-234). (7) 73
Table 8 – Material reference values for pressure vessel nozzles (SA-106). (7) 74
Table 9 – Material reference for pressure vessel nozzle (SA-105). (7) 74
Table 10 – ASME Section VIII Division 1 shell thickness calculations. 77
Table 11 – ASME Section VIII Division 1 head thickness calculations. 78
Table 12 – ASME Section VIII Division 1 nozzle thickness calculations. 79
Table 13 – ASME Section VIII Division 1 nozzle thickness calculations (continued). 80
Table 14 – ASME Section VIII Division 1 minimum fillet weld size for nozzles. 80
Table 15 – Tank weight calculations. 81
Table 16 – Tank capacity calculations. 81
Table 17 – Maximum pressure retention of components ASME equations. 82

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ABSTRACT
The intention of this project was to provide a pressure vessel design to aid a fabrication
shop in obtaining or maintaining its American Society of Mechanical Engineers (ASME)
Boiler and Pressure Vessel Code (BPVC) accreditations. The vessel was to be built by the
fabrication shop to demonstrate their Quality Control (QC) systems and fabrication practices
during a Joint Review. A Joint Review is a triennial process in which the practices, designs
and materials used by the shop are examined to assure compliance with code. Accreditations
can only be granted after a candidate organization shows adherence to code during this
process.
The resulting vessel was designed to the standards presented in ASME BPVC Section
VIII Division 1. It was then fabricated by the Specialty Piping Corporation (SPC) of
Davisville, West Virginia. Construction of the vessel coincided with SPC’s triennial Joint
Review. Before and during the review, the vessel was used to demonstrate SPC’s quality
control and fabrication procedures to an authorized inspector (AI) and a review board, which
included an examiner from the National Board of Boiler and Pressure Vessel Inspectors. The
National Board is generally referred to as the NBIC due to the National Board Inspection
Code.
The vessel design assisted SPC in earning a renewal of their ASME “U” stamp with “W”
designator for pressurized vessels. The “U” indicates certification to construct pressure
vessels, and the “W” indicates welding is the certified form of fabrication.

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INTRODUCTION AND RESEARCH
PROBLEM STATEMENT
The American Society for Mechanical Engineers (ASME) and the National Board of
Inspectors (NBIC) have both developed quality systems and practices regarding boilers and
pressure vessels. Typically, these two organizations work in tandem to ensure the safety and
quality necessary to prevent the loss of life and property due to the failure of high pressure
equipment. Fabrication shops dealing with boilers and pressure vessels require certification
in the standards and practices mandated by ASME and NBIC. These certifications must be
periodically maintained after their initial issuance.
This undertaking will provide the engineering design, fabrication drawings and
calculations to an ASME Code fabrication shop for the purpose of securing or maintaining its
high pressure vessel accreditation. The fabrication shop will need to provide certified
welders, a quality control system, and methods of material purchase and control. All work
provided will meet all of the requirements of ASME Boiler and Pressure Vessel Code,
Section VIII, Division 1. This section is entitled Design and Fabrication of Pressure Vessels.
This activity will result in both shop certification and the fabrication of a demonstration
pressure vessel.
ASME offers 21 certifications based on the scope of industrial activities. Specialized
accreditations include certifications for the construction, inspection, and maintenance of
power boilers, heating boilers, pressure vessels, transport tanks, fiber-reinforced pressure
vessels, nuclear facility components, and nuclear in-service inspection. (1)

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RESEARCH
Gaining ASME accreditation is an intensive task for fabrication operations, and it
typically requires an investment of between $5,000 and $10,000 for fees and inspection costs.
This includes costs paid to the Authorized Inspection agency, the National Board and ASME.
The Authorized Inspection agency (AI) is a third party company that provides code experts to
fabrication shops to assure work is being completed within ASME code. Additionally, AI’s
assist fabrication shops in preparation for inspection by NBIC. The AI agency is contacted,
and a contract is secured for in-process inspections. The vessel must be designed to code and
fabricated from traceable materials. Certified welders are required to function in industry.
The vessel is to be constructed as if it was going to be applied to service in industry. The AI
witnesses critical steps of fabrication. The fabrication process is followed by a Joint Review.
A Joint Review is a meeting of representatives from NBIC, the AI agency, the fabrication
shop’s quality program, and the shop’s management staff. The fabrication shop’s quality
control system is reviewed, as is the design, calculations, and materials of the vessel.
Issuance of ASME certifications is conditional on successful completion of an appropriate
Joint Review. (4)
The Joint Review assesses the applicant’s Quality Control (QC) manual and Quality
Control System (QCS), as well as their implementation. QC manuals must adhere to
ASME’s guidelines of control requirements. The control requirements are dictated by the
scope of work performed at the fabrication shop and may not include all controls
implemented by ASME. The fabrication shop must demonstrate its QCS by performing the
administrative and fabrication activities in accordance with both its own QC manual and
ASME code. Designs supplied to the fabrication shop must adhere to ASME code and
facilitate implementation of the shop’s QCS. (5)
The Joint Review examines the applicant’s material control system. This system ensures
that the material received by the applicant is properly identified with documentation.
Certificates of Compliance or Material Test Reports satisfy code requirements. These
documents can be either hard-copy or electronic. (6) Compliant material is received from the
supplier labeled with its material type and accompanying document number as in Figure 1.
Compliant material properties are listed in tables in ASME BPVC Section II. (7)
Figure 1 – Steel pipe marked for identification. (4)

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Analysis of code calculations occurs during the Joint Review process. Typically,
calculations are generated using computer software. However, applicants must be able to
verify computer generated results. This can be done by using hand calculations or another
computer program. A letter from the software vender verifying the software has been
reviewed is acceptable in some cases. Calculation verification may not be requested, but it
should be expected. (8) Code calculation packages contain roughly 20 pages for simple
vessels. However, the number of calculation pages and calculations required increases as
complexity increases. The properties and abilities of all components and welds must be
analyzed mathematically to determine the vessel’s safety. A calculation sheet example is
depicted in Figure 2.
Figure 2 – Design calculation example (Shell Thickness). (8)

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Proper shape is vital in pressure vessel design. Edges and corners create stress
concentrations, so rectangular shapes are typically not suitable for pressurized equipment.
Spherical vessels can be safely loaded with roughly twice the pressure as a cylindrical vessel
of the same material thickness. (9) However, spheres are very expensive and difficult to
produce. Cylindrical vessels with semi-elliptical heads, or end-caps, are economical and
effective. (10) The most basic pressure vessel configuration consists of a cylindrical shell,
two semi-elliptical end-caps, and two cylindrical nozzles. This shape is conducive to
fabrication, because seamless pipe may be used to fabricate shells and nozzles. Additional
fittings and supports are applied to vessels depending on their applications. Demonstration
vessels require only one inlet and one outlet, and they may be only partially assembled and
welded for a Joint Review. However, they are often fully completed, and modified later to
perform tasks in industry. Modification requires amending designs and calculations. Figure
3 is a design drawing of a demonstration pressure vessel. Figure 4 is a petrochemical storage
tank. Its design is simple but effective. Figure 5 is a more complex vessel. Its construction
includes lifting points, mounting points, bolted and flanged nozzles and supports. Such
fittings should only be applied as necessary, because the added complexity increases costs.
Figure 3 – Demonstration vessel. (8)

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Figure 4 – Petrochemical storage tank. (1)
Figure 5 – Refinery vessel. (1)
See Appendix A for research notes.

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INTERVIEWS
William Ridle, founder and operator of Southport Services, relates that pressure vessels
must be built to ASME code to ensure safety. Customers provide the design conditions for
their pressure vessel, and the task of designing it to code lies with the engineer. Typically,
the customer represents a small entrepreneurial fabrication shop without an engineer on staff.
(2)
Don Didion runs such a business. Didion Mechanical has been operating for 37 years,
and it first gained ASME accreditation in 1989. Currently, 99% of its business is fabricating
ASME code pressure vessels and heat exchangers. His first priority when fabricating a
pressure vessel is that the design meets code. The second priority is that the design package
includes all of the applicable calculations. The third priority is that the vessel is followed by
an in-plant traveler during fabrication. A traveler is a document that technicians use to assure
proper materials are being used. The technicians also sign-off their work on the document.
The fourth priority is that the design includes fit up points for the Authorized Inspector (AI)
to witness. An AI serves as a third party to assure that the vessel is built to code. Mr. Didion
relates that the documentation for all pressure vessels must be organized and retained for at
least three years. (3) However, Didion Mechanical retains these documents for five years.
See Appendix A for additional interview notes.

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CUSTOMER SUPPLIED INFORMATION
SURVEY AND RESULTS
Fabrication shops which have developed specialties in piping and pressurized equipment
comprise the customer base for ASME Code demonstrator pressure vessel designs. These
shops tend to be small operations, and they obtain the majority of their work from general
contractors with limited experience concerning pressurized equipment. These shops
generally do not have an engineer on staff, and they contract engineers for their services
regarding ASME code. (2)
Surveys were distributed to ASME accredited fabrication shops, and the returned
surveys provided data regarding customer features. The survey consisted of three sections.
The first section asked the customers to rate the importance of pressure vessel design
features. The second asked the customers to rate their satisfaction regarding their previous
ASME demonstrator pressure vessel designs. The third section asked the customer how
much they are willing to pay for such a design. The survey results are displayed in Table 1.
Table 1 – Scoring results from survey.
Customerimportance
Designer'sMultiplier
CurrentSatisfaction
PlannedSatisfaction
Improvementratio
ModifiedImportance
Relativeweight
Relativeweight%
ASME Code
Compliant 5 1.1 5 5 1.0 5.5 0.36 36%
Safe 4.8 1.1 5 5 1.0 5.3 0.35 35%
Ease of
Fabrication 3 0.9 3.6 3 0.8 2.3 0.15 15%
Cost 2.4 0.9 3 3 1.0 2.2 0.14 14%
Code compliance and safety are the most important customer features, but ease of
fabrication and cost show the largest potentials for improvement. Therefore, the best strategy
for improving upon demonstration pressure vessel design is gearing the design to be
conducive to fabrication and control cost. This must be done without adversely affecting
code compliance or safety. However, improvement areas are addressed in the designer’s
multiplier of table 1. The designer’s multiplier is assigned to customer features based on the
engineering judgments of the designer. A multiplier of one is a neutral value, it does not
affect the relative weight of the feature to which it is applied. Multipliers less than one
decrease the features’ relative weights, and multipliers greater than one increase their
weights. Even though customers are satisfied with safety and compliance, they must be
considered before all else. It is necessary to apply multipliers that reflect their importance.
This is why code compliance and safety are given multipliers of 1.1. Ease of fabrication and
cost can be improved upon, but their importance is not as great as compliance and safety.

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This is why ease of fabrication and cost receive reduced designer’s multipliers of 0.9.
Planned satisfaction levels for ease of fabrication are actually less than current satisfaction
for that customer feature. This indicates the greater importance of code compliance and
safety to ease of fabrication. The designer is willing to see a decrease in the ease of
fabrication satisfaction rating to assure code compliance and safety.
See Appendix B for the details of the customer survey.

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PROCESSING SURVEY RESULTS
Engineering characteristics and their corresponding relative importance values are listed
in table 2.
Table 2 – Relative Importance of Engineering Characteristics.
Engineering Characteristics Relative
Importance
Design in accordance with ASME Section VIII Division 1 26%
Compliant weld media 25%
Shape 17%
Volume 16%
Welder access to joints 10%
Facilitates authorized inspector’s (AI) activities 6%
The most important engineering characteristic is that the pressure vessel design be in
accordance with ASME Section VIII, Division 1. Proving code compliance is the point of
the product. Therefore, designing within the code takes first priority. Compliant weld media
is nearly as important. Again, this characteristic deals with compliance, and proving
compliance is the purpose of the pressure vessel design.
Shape and volume are secondary characteristics. They dictate the design and
construction of the vessel, but are secondary to compliance. Dimensional characteristics can
vary greatly, but the vessel must be compliant regardless of volume and shape.
Welder joint access and AI facilitation are important. However, they are tertiary
characteristics for the design process. It is necessary to address these characteristics, but
their formation and modification will be dictated by the primary and secondary
characteristics.
See Appendix C for the quality function deployment (QFD) tool used to develop the
weights for the engineering characteristic.

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PRODUCT OBJECTIVES
ASME Section VIII, Division 1 Compliant – 36%
Code compliance is the most important objective of a demonstrator pressure vessel. Its
purpose is to prove to ASME and NBIC that the fabrication shop is capable of building such
a vessel to code while adhering to an approved QCS. ASME applies controls to all aspects of
pressure vessel design and construction, so one missed detail in either will cause a shop to
fail a joint review. Such an occurrence is a waste of time, money and effort. Furthermore, it
could cause an organization to lose professional credibility, which results in lost work and
revenue. Code compliance received a relative weight of 36 percent for customer
requirements, because code compliance is the point of the product.
Safety – 35%
Pressurized equipment is dangerous. ASME issued its first boiler and pressure vessel
code in 1914 to combat frequent industrial explosions due to such equipment. (1) Sub-
standard equipment can injure, kill and/or destroy property. Therefore, the demonstration
vessel design must be able to meet or exceed the mandatory specifications for pressure
loading with the assurance that the vessel will not fail in service if properly constructed,
inspected and maintained. This customer requirement received 35 percent relative weight.
The combined weight with code compliance, which ensures safety, is 71 percent. Built to
code equates with built for safety.
Ease of Fabrication – 15%
Fabrication shops want to earn accreditation to build or continue building equipment for
industry. They do not want to dedicate excessive time, personnel, materials or facilities to
fabricating a demonstration pressure vessel. Therefore, the designer must take into account
the ease in which the vessel can be constructed. The shape of the vessel must be conducive
to welding, and it must allow the welder easy access to seams. Additionally, the shape of the
vessel should allow easy observation and inspection by the AI. The AI and the Joint Review
may only require a portion of the vessel to be completely welded by the time of the joint
review. This facilitates the operations of the fabrication shop, while satisfying the AI and
ASME in the shop’s ability to fabricate pressure vessels.
The size of the vessel must be large enough to permit access to welders and inspectors,
but it should be small enough to facilitate handling during the fabrication process. It is also
desirable that the vessel be of a size that is useful in industry. This will permit the shop to
incorporate the vessel into future projects. Vessel weight should allow handling and
transport. The capacity of trucks, fork lifts, cranes and other handling or transportation
equipment must not be exceeded. A target weight limit of under 1000 pounds is instated to
assure the vessel is able to be readily fabricated and transported.
Cost – 14%

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Vessels are often constructed using lengths of seamless pipe and forged or cast end-caps.
Components are attached by welding using common weld media. These materials are
relatively inexpensive compared to the labor rates of certified welders. It is necessary to
account for both material costs and labor costs in the design process. Target goals are set to
prevent the fabrication shop from expelling more resources than necessary on the
demonstration pressure vessel. The fabrication shop should not have to spend more than
$2000 on materials, and the vessel should require no more than 50 labor hours to fabricate.
See Appendix D for details of product objectives.

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DESIGN
DESIGN ALTERNATIVES
Traditionally, pressure vessels are constructed from steel cylinders with caps on each
end. However, other shapes and materials are available for consideration.
Pressure vessels may be constructed to any shape which forms an enclosure to retain a
fluid. Vessels may be shaped to fit irregular cavities and utilize limited available space.
However, corners and complex shapes are most often avoided in vessel design. Corners
provide points and seams for stress concentrations. Square or rectangular shaped vessels are
possible, but corners are rounded to reduce concentrations. Such vessels are limited to the
degree in which they can be safely pressurized when compared to spherical or cylindrical
vessels of similar volume. Complex shapes are difficult to analyze for safe operation, and
they are difficult to construct. Irregular or rectangular vessels can be economical when mass
produced for use in consumer products. Generally, they are poorly suited for industrial
applications, which tend to require custom vessels. Occasionally, industrial vessels of
rectangular shape are built to suit a specific need, such as the vessel pictured in Figure 6.
Although it is possible that a fabrication shop seeking ASME accreditation may need to build
a rectangular or irregularly shaped pressure vessel, the shops would avoid using a rectangular
design whenever possible.
Figure 6 – Rectangular pressure vessel for use in an effluent treatment plant. (11)
Spheres provide the most efficient shape for pressure retention. A spherical vessel can
retain roughly twice the pressure of a cylindrical vessel of the same wall thickness. (9)
However, spherical vessels are relatively rare. This is due to the difficulty of fabricating the
shape. Vessels, such as that depicted in Figure 7, are relatively expensive compared to
cylindrical types of comparable volume.

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Figure 7 – Spherical pressure vessels for the storage of liquid natural gas. (12)
Composite materials are gaining use in pressure vessel construction. These materials
allow for light-weight vessels with the pressure retention capabilities of their steel
counterparts. Composite pressure vessel are generally employed to save weight within a
system. Typical applications include aerospace, diving, and compressed natural gas (CNG)
transport. Until recently, these vessels have required a metal or plastic liner to provide a base
structure and prevent leakage through micro-cracks in the composite resin matrix. The
composite material is then wrapped around the structure. However, Composite Technology
Incorporated of Lafayette, Colorado has recently fabricated an all-composite, liner-less vessel
for installation in the US Air Forces’ FASTRAC 1 satellite, which is depicted in Figure 8.
(13) Although composite vessels provide weight savings, their construction is extremely
expensive. Typically, small shops seeking ASME accreditation do not have the capital to
produce composite vessels with or without liners.
Figure 8 – Liner-less composite pressure vessel for FASTRAC 1 satellite. (13)
The design of composite vessels was explored using SolidWorks design software.
Figure 9 illustrates the software’s ability to render carbon fiber texture on parts.

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Figure 9 – SolidWorks rendering of composite pressure vessel.
SolidWorks was also used to explore the design of spherical vessels. The vessel
depicted in Figure 10 is comprised of eight sections. Four sections are joined to produce a
hemisphere, and two hemispheres are joined to produce a sphere. Large spherical vessels,
such as those shown in Figure 7, are constructed by joined sections. However, this is done
only when necessary because the complex shape of each section is difficult to fabricate.
Figure 10 – SolidWorks rendering of a spherical vessel produced from sections.
Hemispherical shapes, such as that in Figure 11, are available for use as pressure heads
from process piping and pressure vessel suppliers. These components are custom fabricated
and typically produced from sand casting or forging. They are generally very heavy and
thick. Their typical applications are very high pressure vessels of great size. Two such
hemispheres could be joined to produce a pressure vessel as depicted in Figure 12. However,
the size, weight, and cost of these components make them impractical for use in a
demonstration pressure vessel.

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Figure 11 – Hemispherical head cap. (14)
Figure 12 –Hemispherical caps joined to produce a pressure vessel.
Fabrication shops seeking accreditation in ASME Boiler and Pressure Vessel Code, will
typically construct their demonstration vessels from steel pipe, pipe caps, and fittings. These
materials are common in fabrication shop operations, and they are readily available. If the
demonstration vessel will be used in an industrial application, the application dictates the
design of the vessel. However, if the vessel will only be used for accreditation, the design
reflects the shop’s current work-scope. Often, demonstration pressure vessels are designed
and constructed to utilize materials already on hand.

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DESIGN SELECTION
Specialty Piping Corporation (SPC), of Davisville, West Virginia, specified
requirements for a demonstrator pressure vessel design. SPC serves the Mid-Ohio Valley
area as a general construction contractor. Their listed contracting specialties include
mechanical, structural, architectural, pipe fabrication, civil, plumbing, electrical, and
excavation. (15) The company currently holds ASME “U” and “PP” stamps, which indicates
their qualifications for Section VIII division 1 pressure vessels and pressure piping. The “U”
stamp is accompanied by a “W” designator to indicate the certification is for vessels
fabricated by welding. This pressure vessel design and Joint Review will maintain their
ASME “U” stamp with “W” designator.
The vessel is a demonstration vessel, but it will be designed as a decanter. A decanter is
a vessel which holds the decantation of a liquid. Decantation is the process of separating
sediment from a liquid by removing a top layer of liquid after the sediment settles. This tank
holds the decanted fluid, but it does not separate the fluid from the sediment.
The specified design temperature is 300°F, and the design pressure is 50 pounds per
square inch. The company would like to utilize excess steel piping located at their facility.
At this point, it is necessary to rule out composite materials for the design of the vessel.
Specialty piping does not have the ability to construct composite vessels, and their work-
scope and experience favors steel components. Additionally, spherical shapes can be ruled
out as well. The company wants a small vessel to demonstrate their fabrication and quality
control systems. A spherical pressure vessel consisting of segments would prove difficult to
produce, especially on a small scale. Two joined hemispheres may not be appropriate to
satisfy the AI and Joint Review examiner of the shop’s quality control system. Furthermore,
the hemispherical vessel halves would be expensive to procure. A cylindrical design is most
appropriate for this application. SPC is skilled and knowledgeable in fabricating vessels in
this manner, and it will satisfy the AI and review board.
The design was dictated by the ASME approved material already on hand at SPC. The
vessel will have a conventional arrangement. Its basis will be a cylindrical shell, and the
shell will be closed at both ends by semi-elliptical end-caps. Two nozzles will be affixed to
the heads, one at each end. One will serve as an inlet port, and one will serve as an outlet
port. Provisions for a data plate are required, but an actual data plate is not required.
Various sizes of seamless steel pipe were in stock at the shop. This material is commonly
used to produce pressurized piping systems for SPC’s customers. Additionally, semi-
elliptical pipe heads and fittings were available in various sizes at the shop. A six inch
diameter nominal pipe size was selected to form the vessel’s shell. A shell length of two feet
was specified to provide a compact a size, but allow the vessel enough area to dissipate heat
during welding processes. The compact size allows the vessel to be moved and oriented by
one technician during fabrication. This decreases the labor costs required to build the vessel.
Semi-elliptical heads were selected to provide pressure retention efficiency, and they were
sized to match the shell. Semi-elliptical heads produce less pressure concentrations than flat
or torispherical heads, but they are not as expensive as hemispherical or conical heads.

22
Additionally, they were available at the shop. Threaded fittings used as nozzles permits easy
installation to an exterior system.
A proof of design statement is available in Appendix G. This states the criteria on which
the design of the vessel will be judged.
SHELL
The shell serves as the basis of the pressure vessel. Its dimensions determine the size of
the heads, the volume of the vessel, and much of its ability to retain pressure. The shell’s
diameter must be large enough to facilitate welding, and allow the AI unrestricted access
during in-process weld inspections. Furthermore, the shell’s diameter coupled with its length
must provide sufficient volume to hold decanted fluid. Costs increase as shell diameters
increase. Therefore, it is important to design the shell with a diameter that is large enough to
serve as a decanter, plus facilitate fabrication and inspection. However, it should be no larger
than necessary.
The shell’s material composition and wall thickness determine its ability to retain
pressure without the risk of rupture. The shell must not only be strong, but it must also be
thick enough to retain sufficient strength after a layer of corrosion has formed within it. The
wall thickness must not be so great as to needlessly reduce the interior volume of the vessel.
Furthermore, an unnecessarily thick wall requires unnecessary grinding and welding to join
the other components. Shell design or selection requires a balance of factors. For this case,
it is desirable to choose an appropriate shell size, select mating components, and analyze
each of them to determine the safety of the vessel. Prefabricated steel pipe performs well as
pressure vessel shells, and commercially available pipe sizes are presented in Table 3.
Table 3 – Pipe sizes available for use as shell. (16)

23
SPC indicated that the vessel should weigh less than 70 pounds, and be small enough for
handling by one person. This would allow the vessel or its components to be moved easily
within their shop. SPC also indicated that several pipe sizes were available to construct the
vessel. These included schedule 40 nominal inch sizes 5, 6, 8, 10 and larger. The larger
sizes were eliminated from consideration due to their cost and the costs associated with
welding large diameter pipe. Additionally, larger sizes would produce a vessel heavier than
100 pounds and require more than one person to handle. Five inch nominal pipe was also
eliminated due SPC’s lack of 5 inch semi-elliptical end caps to which the shell would mate.
Six inch nominal diameter schedule 40 pipe was selected, because it is small enough to
form the structure of a compact vessel. SPC had both the pipe and its end-caps on hand. The
length of the shell was sized for handling by one person. The pipe weighs slightly less than
20 pounds per foot of length. Two feet would produce a shell of 40 pounds and leave 30
pounds for the heads, nozzles, fittings and bracket. One foot of length would produce a
compact vessel, but the vessel would only have one and a half gallons of capacity.
Additionally, welding is likely to be complicated by such a small shell due to the lack of
surface area to dissipate heat. This may cause the components to warp. A 36 inch shell
would weigh nearly 60 pounds. This would only leave 10 pounds for the other components,
and it may produce an overweight condition. 24 inches was stipulated to provide for a
compact vessel with minimal weight, but supply sufficient volume for a decanter and allow
adequate surface area for heat dissipation during welding. A vessel formed from six inch
nominal diameter pipe of 24 inches in length suits both SPC’s and the AI’s needs for the joint
review.
HEADS
Common types of cylindrical pressure vessel heads include semi-elliptical heads,
torispherical (dished) heads, conical heads, flat heads and hemispherical heads.
Flat heads are useful in pressure vessel applications where pressures are not exceedingly
high. They are often used on large vessels to minimize length when positioned horizontally,
or minimize height when the vessel is positioned vertically. The flat head design is
employed when space is a concern at the ends of the vessel. A vertical vessel may employ
this head to provide clearance between the vessel and a ceiling or overhead equipment. In
some applications, brackets or feet are welded directly to the lower head of a vertically
oriented pressure vessel. This aids stability when the vessel is rested directly on the head.
Flat heads are limited in their ability to retain pressure by the 90° transition between vertical
and horizontal surfaces, as seen in Figure 13. This transition is an area of stress
concentration. Increasing the radius of the transition reduces the stress concentrations, but
increasing the radius also increases the head’s height. This negates the space saving attribute
of the flat head.

24
Figure 13 – Flat head. (17)
Torispherical heads are comprised of a domed (or dished) section of a fixed radius, and a
flange, or knuckle, for fitment to a shell. The dome is relatively shallow, and it drastically
transitions to the knuckle as can be seen in Figure 14. This transition produces an area of
potential stress concentration for a pressurized vessel. For like sizes, thicknesses and
pressures, the torispherical head is better for pressure retention than flat heads.
Figure 14 – Torispherical head. (17)
Semi-elliptical (2:1) heads, as illustrated in Figure 15, are deeper than torispherical
heads, so they are more difficult to form. They are often referred to as 2:1 or “two to one”
heads. This is because the depth of the ellipse is roughly half of the head’s radius. When
compared to dished heads, the increased radius of the head permits a smoother transition
from the flange to the domed section. This reduces possible stress concentrations and allows
for a greater pressure retention.
Figure 15 – Semi-elliptical head. (17)
Hemispherical heads provide the best pressure retention ability amongst heads of the
same wall thickness. The shape provides the greatest surface area and the best distribution of
pressure for any size of vessel or thickness of wall. Unlike the heads discussed previously,
there is no transition between vertical and horizontal elements of the head, because it is
comprised of one surface, as seen in Figure 16. Hemispherical heads are more expensive
than other types due to their material requirements and relative difficulty to form. These
heads also require more space at the ends of the vessel.

25
Figure 16 – Hemispherical head. (18)
Conical heads provide pressure retention attributes similar to those of dished heads.
Their areas of stress concentration are at the transitions between surfaces, but increasing radii
of transitions or decreasing the angles between the sides of the conical walls (α in Figure 17)
decreases stress concentrations. Conical heads have a greater height per diameter than types
discussed previously, so they are employed when needed. They are used for specialized
applications in vertical vessels. A conical head may be positioned at the top of a vertical
vessel to trap gasses or vapors, such as in distillation tanks. Conical heads may be used at the
bottom of a vertical tank to trap particulate, such as in brewery mash tanks.
Figure 17 – Conical head. (17)
Conical heads are not needed for Specialty Piping’s demonstration vessel. It is assumed
the decanter will hold decanted fluid, not trap particulate. Hemispherical heads are ruled out
as well. The added size and cost is not warranted. It is desirable to avoid the stress
concentrations prevalent in flat and torispherical heads. Semi-elliptical heads are preferred
over the other two remaining types due to their pressure retention capabilities. They are a
common fitting which SPC stocks in bulk.
NOZZLES
Nozzles connect pressure vessels to the systems which they service. This task can be
achieved using a variety of methods. Pipes and pipe fittings are the most common
connections. Typically, they are either threaded or flanged to provide a means with which to
connect to a system without the leakage of fluid between the system and its surroundings.
Specialty Piping has indicated the need for the nozzle to be a 1 inch 3000 pound-rated
threaded coupling as pictured in Figure 18. SPC commonly uses this type of fitting and it is
readily available. This fitting, used as a nozzle, allows the vessel to be installed to a system
with the use of standard 1 inch pipe. The couplings can be welded directly into a port cut
either in the shell or in the heads of the vessel. For this application, the customer calls for the

26
nozzles to be installed at opposing ends of the vessel. This requires the nozzles to be welded
into cavities cut into the apex of each head.
Figure 18 – One inch, 3000 lb.-rated, threaded coupling.

27
WELDS
Considerations for weld design include accessibility, penetration, strength, and economy.
Accessibility ensures that the welder has access to the joint, which provides her or him with
the ability to join the components. Penetration ensures that a bond is formed through the
entire thickness of the joining components. Full penetration prevents irregularities in the
material. For pressure vessels, irregularities produce stress concentrations, and stress
concentrations weaken the vessel. Economy is considered for both the sake of the fabrication
shop operator and the quality of the product. Fabrication shop operators prefer to spend less
money on frequently used supplies such as weld media, and they prefer not to spend money
on labor rates for unnecessary welding. Furthermore, excessive welding increases the
possibility of imperfections in the system and detracts from the product’s appearance.
However, it is necessary to design a welded joint strong enough to fulfil its function. These
considerations require balance.
The size of the vessel dictates that welding can only be performed from the outside.
Therefore, it is necessary to select weld designs that deliver full penetration from the exterior
of the vessel. Butt-welds are acceptable for joining vessel heads to shells. (6) (UW-13).
However, a square butt joint is not acceptable for this application, because such joints do not
have the penetration to bond the metal entirely through the thickness of the vessel wall.
Single beveled butt-joints require shallow angled cuts from one side to achieve full
penetration. Such shallow angled cuts require excessive part preparation and weld media.
Therefore, it is practical to utilize a single-V butt-joint or a single-U butt-joint to form the
seam. These joints provide full penetration, but they require the removal of parent metal.
This necessitates the use of additional weld media to fill the space left from the removed
metal. Single-V joints are easier to produce than single-U joints, because the V shape
requires the components on both sides of the joint to receive a simple fillet as can be seen in
Figure 19. The U shape requires more complex cutting. The single-V butt weld benefits
from a convex crown over the exterior of the weld. This minimizes internal stresses which
form as the metal and weld media cool. This type of welded joint is selected to join the shell
and heads of the vessel.
Figure 19 – Single-V butt-joint. (19)
The head to nozzle joints require a different weld design, because the parts do not mate
in the same manner. Instead the goal is to affix a cylinder, the nozzle, into a hole at the apex
of a dome shape, the head. Only material removal from the head will permit access to the
root of the weld. The minimum amount of material should be removed to prevent elongating
the cavities which accept the nozzles. Additionally, minimizing material removal minimizes
weld material required to fill the space left by beveling. This joint requires beveling for full
penetration of the root welds, but the bevel provides limited access to the joint for the welder.
Fortunately, the welder can approach the joints directly from the front and rear of the vessel

28
to improve access. Additional strengthening for the joint is applied through a fillet weld,
which is positioned over the root welds at the base of the nozzle, as depicted in Figure 20.
Information on welded connections to pressure vessels can be found in paragraphs UW-15,
UW-16, and UW-18 of the ASME BPVC Section VIII Division 1. (6)
Figure 20 – Beveled weld with strengthening fillet. (20)
The welds to affix the bracket are specified as two sided fillet welds. The welds are 1
inch long and spaced at five inch intervals. The C-channel bracket makes irregular angles to
the surface of the cylindrical shell. Fillet welds can bridge enough space between the shell
and the bracket to fill around the shallow penetrations at the root of the welds. A two sided
approach improves strength. The bracket is 7.5 inches long, and the welds are spaced at 5
inch intervals. This permits the welds to be laid without reaching into the space between the
bracket and the shell. The four, one inch welds provide enough strength to affix the bracket
to the shell.

29
ADDITIONAL COMPONENTS
ASME requires the application of data plates to all pressure vessels applied to industrial
service. This includes demonstration pressure vessels applied to industry, but it does not
include demonstration vessels that are not put into service in industry. In the case that this
vessel were to be applied to industry, its data plate would display the ASME logo, the
certifying authority (National Board of Inspectors), the name of the fabrication firm
(Specialty Piping Corporation), the firm’s location (Davisville, WV), the maximum
allowable working pressure at maximum temperature (50 psi at 300°F), the maximum
operating pressure at minimum temperature (50 psi at -20°F), the manufacturer’s serial
number, and the year of fabrication (2013). The data plate would also contain the “U” and
“W” symbols to indicate the vessel has been fabricated under ASME BPVC for pressure
vessel construction by welding fabrication.
This vessel will not be applied to industry. Instead, it will be tested and displayed as a
demonstrator. A data plate is desirable to emulate a vessel applied to industry. However,
ASME compliance markings and a corresponding NBIC registration are expensive and
unnecessary. Therefore, the data plate can include all of the elements listed above except for
ASME or NBIC symbols and markings. The data plate is also to contain the phrase “Not an
ASME or NBIC data plate.” This indicates that the vessel is not registered as an industrial
service vessel and should not be used as such. This is intended to prevent legal
complications or confusion concerning this vessel’s use. This vessel’s purpose is to gain
accreditation, and industrial use requires registration.
The data plate mounts to the bracket, which is welded to the vessel. Rivets or adhesive
fix the data plate to the bracket. C-channel provides the material for the bracket. The
channel is available in various sizes and it can be cut to length to accommodate the data
plate. The runners, or legs, of the channel can be welded to the outer surface of the shell.
The back of the channel provides a flat surface for mounting the bracket.
Additional components are required for the vessel to retain pressure and to control fluid
flow into and out of the vessel. Ball valves are easy to use, inexpensive and capable of
retaining the required pressure. The size of the valves are matched to the size of the nozzles.
The pressure retaining capabilities of the valves are verifiable using the valve manufacturer’s
data sheet. (21)
It is necessary to measure the pressure within the vessel, and gauges are readily
available. It is desirable to select a gauge with a range which includes the operating and
design pressures plus 50 to 100% to read over pressurized conditions. Gauges should be easy
to read. When possible, select a gauge in which the operating pressure is at the middle of the
range. This provides an easy to recognize visual condition in which the needle points up
when the vessel is retaining its operating pressure. The gauge’s pressure rating is indicated
on its packaging and dial face.
Pipe nipples and fittings are required to mate the valves and gauge to the pressure vessel.
The plumbing nipples are rated at 700 psi (22), and the pressure gauge adapter and tee are

30
both rated at 300 psi at design temperature. (23) (24) All prefabricated components are rated
to pressures well above the design pressure.
Vessel inlet and outlet fitting arrangements are pictured in Figures 21 and 22. These
components are available for minimal cost at most local hardware stores. In this case, their
pressure ratings are well above the design pressure of the vessel.
Figure 21 – Gauge, ball valve and fittings for outlet nozzle.
Figure 22 – Ball valve and fitting for inlet nozzle.

31
FINAL DESIGN
The final design incorporates a shell made from schedule 40 pipe with a six-inch
nominal diameter and a length of 24 inches. The shell is capped at the ends with two semi-
ellipsoidal heads, which provide pressure retention strength with economy of both size and
cost. Nozzles are mounted at the center of each head to provide connections to an exterior
system, and C-channel is used to form a flat bracket for mounting a data-plate. The shell’s
dimensions determine the overall size and volume of the vessel. The size is a benefit to the
fabrication shop due to the reduced material and labor costs of fabricating a compact vessel.
The volume has little effect on the fabrication shop’s desired accreditation, so the volume of
roughly three and one-half liters is adequate. Figure 23 is the shop drawing supplied to SPC
for fabrication of the vessel, and Figure 24 is a solid rendering of the components which they
joined to form the vessel.
Figure 23 – Decanter pressure vessel construction drawing.

32
Figure 24 – Components welded by SPC.
Figure 25 is a solid rendering of the vessel complete with valves, a gauge, couplings, and
the fittings required to link the components. Figure 26 is an assembly view of the vessel with
fittings.
Figure 25 – Rendering of assembled vessel.
Figure 26 – Exploded view of vessel.
See appendix H for Component drawings and illustrated bill of materials.

33
PRESSURE LOADING ANALYSIS
ASME ANALYSIS
ASME’s design analysis system is complex. It has been constructed and adapted over
many years to reflect vessel design, construction and use in industry. The calculations
include multipliers such as joint efficiencies. Joint efficiencies are factors relating the
confidence a designer, fabricator, customer or examiner may have in the joints of a
prefabricated component or a newly constructed joint. A joint that has received a full
radiographic inspection without the detection of defect can be assigned an efficiency of one.
Joints which have receive a spot inspection without the detection of defect receive a joint
efficiency factor of 0.85. Joints which have not been inspected, but have been fabricated by
competent and certified firms or individuals are assigned joint efficiencies of 0.7. An
efficiency of 0.85 is assigned to the seamless steel pipe which forms this pressure vessel’s
shell with the knowledge that the pipe has been supplied from a reputable and certified
manufacturer, and samples of the pipe have been radiographically inspected. ASME takes
such factors into account in order to be safe-sided.
In ASME Code, the design thickness is the smallest acceptable thickness of a pressure
vessel component. The wall thickness of the pipe used to form the shell of the vessel is over
three times greater than the calculated design thickness. The actual thickness of the head is
three and one-half times the design thickness of the head. The nozzle is the weakest
component of the vessel with an actual thickness of two times its design thickness. The
vessel is sufficiently strong enough to retain 50 psi of pressure. The selections of shell,
heads, nozzles and welds are acceptable under the standards set forth by the ASME Boiler
and Pressure Vessel Code (BPVC) Section VIII Division 1. (6)
Pressure retention capabilities of the vessel components were calculated following
their selection, and their pressure retention capabilities are compared in Figure 27. The
ASME design thickness formulas were algebraically rearranged to yield the maximum
allowable pressure for each component given their material strengths, dimensions and joint
efficiencies. The shell proved to be the pressure retention limiting component of the vessel.
It can safely retain just under seven-hundred pounds per square inch of pressure. The
tangential stress around the circumference of the shell is the likely point of failure if the
vessel is over-pressurized to 700 pounds per square inch. These calculations assumed
maximum loss of material due to corrosion by incorporating the design corrosion allowance.
However, these calculations do not incorporate the possibility of imperfections in the welds
which join the components. Additionally, these calculations do not consider the pressure
retention abilities of the fittings, valves, and gauges required to monitor and control the flow
of fluid into and out of the vessel. Even though the smallest pressure retention component
value was greater than the rated pressure of the vessel, the design pressure of 50 pounds per
square inch at 300°F should not be exceeded.

34
Figure 27 – Pressure Retention Capabilities of Welded Components.
Reference values for allowable material stresses are available in Appendix I. Vessel
weight, capacity, design thickness and component pressure retention capability calculations
are available in Appendix J. (7)

35
SUPPLEMENTARY ANALYSIS
A supplementary analysis of the vessel shell was conducted. The secondary analysis
was performed using equations derived in texts regarding machine elements. (25) The
additional analysis presents a second tool for comparison against ASME vessel design code
calculations.
This method of shell analysis produces a map of internal stresses within the shell of the
vessel. Figure 28 illustrates that tangential stresses are greatest at the interior surface of the
shell, and that the radial stresses are most negative at this point. A negative radial stress
indicates a state of radial compression. The tangential stresses decrease slightly toward the
exterior of the vessel. The radial stresses grow less negative toward the exterior of the vessel
until there is a radial stress value of zero at the exterior surface of the vessel.
Figure 28 – Plot of interior stresses within shell.
The supplementary analysis has produced low values for compressive radial stresses and
relatively low values for circumferential tensile stresses. The highest value for tensile stress
obtained from this method is 567 pounds per square inch. This is well below the steel’s
allowable stress of 14,600 pounds per square inch at design temperature.
Appendix K contains the stress calculations used in this supplementary analysis.
-100
0
100
200
300
400
500
600
3.0325 3.0825 3.1325 3.1825 3.2325 3.2825
Stress(lb/in2)
Distance from shell centerline (in)
Stress within Shell
Radial Stress Tangential Stress

36
COMPARING ANALYSES
Comparing the ASME analysis with the supplementary analysis requires they provide
values for the same variable. The ASME analysis for circumferential stress was arranged to
yield values for stress.
The circumferential stress values for the analysis methods differ by 17%. The reason
for the difference is that the ASME equation is a guideline for the design of a vessel. It is
meant to deliver safe sided results. The joint efficiency, E, is the code equation’s factor of
safety. Replacing the design joint efficiency of 0.85 with the ideal joint efficiency of 1
produces a circumferential stress value of one percent of the supplemental analysis.
The supplementary analysis supports the ASME analysis without the inclusion of the
joint efficiencies. Both indicate that the maximum circumferential stress within the shell of
the loaded pressure vessel is four percent of the maximum allowable stress of 14,600 pounds
per square inch.
The calculation comparisons are available in appendix L.

37
FABRICATION, JOINT REVIEW & TESTING
FABRICATION
Fabrication of the vessel was performed by the Specialty Piping Corporation of
Davisville, West Virginia. The construction of the vessel served as a vehicle to demonstrate
their material control, quality control, welding and fabrication procedures for their Joint
Review on Tuesday, December 19, 2013. Some procedures were selected as critical
inspection processes by the AI. These procedures were witnessed by the AI to assure that
they adhered to ASME code and the shop’s quality control manual.
Material selection and preparation commenced on Tuesday, December 10, 2013.
Material for the vessel’s shell, heads and nozzles were removed from SPC’s stock and
segregated in an area specified for the vessel. Documentation on file at the fabrication shop
included the material purchase orders, material receiving reports, and material transfer
reports. This documentation included the points of origin of the materials, as well as the
materials’ specifications and grades. This information was then transferred to a document
called a traveler. A traveler is a document originated by the fabrication shop. It includes a
list of welds, hold points (for AI inspection or observation), job number, drawing number,
customer, and test requirements. Each fabrication procedure is accompanied by a space in
which a qualified technician may sign for her or his work. After completion of the vessel,
the traveler is retained on file by the fabrication shop for a minimum of 3 years. Fabrication
commenced after the required materials had been gathered and the traveler had been
prepared.
Fabrication was performed by SPC’s personnel. The personnel are certified under
ASME Boiler and Pressure Vessel Code (BPVC) Section IX – Brazing and Welding
Qualifications. The components were prepared for assembly by cleaning and grinding of the
mating surfaces. This formed the angles between mating components necessary to achieve
full weld penetrations and conformance to design drawings. After surface preparations, the
components were tack-welded to form the shape of the vessel. This allowed the AI to assure
the fit conformed to alignment tolerances stipulated in ASME BPVC. After the AI was
satisfied with the alignment of the components, he gave permission to SPC personnel to
perform the nozzle to head weld at one end of the vessel. Additionally, permission was given
to complete half of the shell to head joint at one end of the vessel. This partial welding
permitted the AI and NBIC examiner to inspect both sides of the welded joints during the
Joint Review.
The remaining seam welds were performed following the Joint Review on December 19.
The welding was completed by the first week of January 2014 following 2 weeks of reduced
production at SPC due to the holiday season. Figures 29 and 30 present the vessel following
the completion of welding.

38
Figure 29 – Pressure vessel after completion of welding.
Figure 30 – Alternate view of pressure vessel with all welds complete.
Figure 31 presents Specialty Piping’s fabrication shop in Davisville, West Virginia, and
figure 32 presents an example a process piping assembly prepared at their shop.
Figure 31 – Specialty Piping Corporation’s fabrication shop.
Figure 32 – Example of a Specialty Piping Corporation process piping project.

39
Additional components were applied to the pressure vessel to permit attachment of
the vessel to a pressurized system. These components included valves, a gauge, couplings,
and the fittings required to mate adjacent parts as pictured in Figure 33. Threaded pipe
fittings received polytetrafluoroethylene (PTFE) tape to lubricate the threads, so they may be
turned more easily to the point of plastic deformation. This provides an effective seal. The
fittings, valves and gauge were installed using specialized pipe and standard wrenches.
Figure 33 – Ball valve, gauge, and fittings connections using PTFE tape.
Following pressure testing, paint was applied to the vessel. A high temperature
spray-can paint was selected from Rustoleum. Black was selected for the base color to hide
discoloration in a dirty or sooty environment. White was selected for the lettering due to its
contrast with the black body of the vessel. As can be seen in Figure 34, the lettering displays
the maximum pressure rating at the maximum temperature to provide a clear indication of the
limits of the vessel. This acts in conjunction with the operating range specified on the data
plate. Stenciling reading, “University of Cincinnati” is applied in red to the back side of the
vessel to prepare the vessel for public display as pictured in Figure 35.
Figure 34 – Maximum pressure and maximum temperature indicated in large lettering.

40
Figure 35 – Included for public display at the University of Cincinnati.
This vessel will not be applied to industry. Instead, it will be tested and displayed as a
demonstrator. However, a data plate is desirable to emulate a vessel applied to industry.
Therefore, the data plate includes the manufacturer name, the firm’s location, the maximum
allowable working pressure at maximum temperature, the maximum operating pressure at
minimum temperature, the manufacturer’s serial number, and the year of fabrication. ASME
compliance markings and a corresponding NBIC registration are expensive and unnecessary,
so this data plate states, “Not an ASME or NBIC data plate.” This vessel’s purpose is to gain
accreditation, and industrial use requires registration. The plate had been cut from a sheet of
0.100 stainless steel. The lettering pictured in Figure 36 was cut into the plate using a Jet
350017 milling machine. The lettering was enhanced using black acrylic hobby paint to
accentuate the lettering as can be seen in Figure 37.
Figure 36 – Data plate with machined lettering.

41
Figure 37 – Data plate lettering accentuated with hobby paint.
The data plate was applied following painting. Originally, the data plate was to be
affixed with four solid rivets, one at each corner. However, the rivets proved difficult to
deform at the buck-tail due to the small space between the data plate bracket and the shell.
This area did not have sufficient clearance to fit a bucking bar to deform the rivets, so JB
Weld’s two part epoxy high temperature adhesive was used instead. This adhesive has a
rated strength of 3,960 psi when cured, and it can withstand temperatures of 550°F. Use of
this bonding agent requires that mating surfaces be prepared by paint removal and cleaning
before the application of the adhesive. Surface preparation on the data plate bracket is
pictured in Figure 38.
Figure 38 – Prepared data plate adhesion surface.
Vessel fabrication was completed on Monday, March 17, 2014. The front view is
pictured in Figure 39, and the rear view is pictured in Figure 40.

42
Figure 39 – Completed Vessel (front).
Figure 40 – Completed Vessel (rear).
An illustrated bill of materials is in Appendix H, and a complete list of components is
available in the bill of materials in Appendix F. Appendix H illustrates the assembled
components, and Appendix F lists these components plus all consumable materials used on
the vessel. The consumable materials include weld media, paints, sealants and adhesives.

43
JOINT REVIEW
Specialty Piping Corporation’s triennial Joint Review occurred on Thursday, December
19, 2013. Attendees included:
 Quality Control Manager of Specialty Piping Corporation (SPC)
 Examiner from The National Board of Boiler and Pressure Vessel Inspectors (NBIC)
 Code Services Supervisor from Hartford Steam & Boiler (HSB) Global Standards
 Authorized Inspector from HSB Global Standards
 Senior Engineer from Southport Services (Specialty Piping’s engineering services
contractor)
 Engineering Assistant for Southport Services
ASME provides a checklist for applicants to complete before Joint Review. The
checklist summarizes the requirements of applicant shops, and serves as a guide for the Joint
Review process. (5) Common practice amongst ASME accredited shops is to modify the
checklist to produce a list customized to the specific shop and its work scope. Such a
checklist was used by SPC to prepare for the Joint Review. See Appendix M for an example
of a modified checklist. (26)
The Joint Review was presided over by the examiner from the National Board of Boiler
and Pressure Vessel Inspectors. The proceedings began with introductions, roll call, and a
brief preview of the planned sequence of the review.
The shop’s quality control manual was reviewed to assure clarity and adherence to the
latest standards of ASME’s BPVC. The examiner from NBIC suggested revisions to the
wording of SPC’s quality manual to improve its perceptibility. Unnecessary wording was
recommended for deletion. Required changes were specified to conform to the latest
revisions of the code. First, ASME is changing the schedule in which the BPVC is issued.
Previously, a new version of the BPVC was issued every three years, with addenda issued
every year between versions. Starting in 2014, ASME will issue a new version of the code
every 2 years with no addenda between versions. Another change to ASME code involves
changes to the stamping system on code compliant vessels. Previously, ASME compliant
equipment was marked with the letters ASME surrounded by a clover-like symbol and a
designator located below it, such as in the example depicted below (Figure 41). The “U”
designator indicates a high pressure vessel.
Figure 41 – Former ASME marking system example. (6)

44
As shown in Figure 42, ASME’s new equipment marking system will have the
designator surrounded by the clover-like symbol for simplicity.
Figure 42 – New ASME marking system example. (1)
Revisions to the QC manual were recommended to clarify welder requirements
regarding weld marking. ASME code requires that each weld on a vessel be signed for by
the performing welder on the traveler. According to the code, marks made by the welder on
the vessel, adjacent to the applicable welds, are optional. SPC requires that their welders
mark each of their welds on the vessel. One weld mark is acceptable if the only one welder
worked on the vessel. Specialty Piping acknowledged their intention to continue their vessel
weld marking practices, even though they exceed code requirements.
SPC’s Quality Control manual required revisions regarding subcontractors. Firms or
individuals contracted by the shop for non-destructive inspections are required to follow
ASME code inspection standards, and firms or individuals contracted to calibrate SPC’s
equipment must abide by ASME’s calibration standards. Subcontracted firms and
individuals require current certifications at the time of their service for SPC, and this is to be
annotated per the QC manual.
The demonstrator vessel’s design and calculations were then reviewed to assure
compliance to code. One discrepancy in the code calculations was discussed during the Joint
Review. The discrepancy concerned nozzle thickness calculations. To determine the
required wall thickness of the nozzles, the nozzle is treated as a piece of straight seamless
pipe. Once the required thickness of the straight seamless pipe is determined, equivalent
fittings can be selected from ASME/ANSI table B16.11. The initial calculation for the
required nozzle thickness used the maximum allowable material stress value for the schedule
80 pipe equivalent of the forged nozzle. The maximum allowable material stress value for
the forged steel fitting should have been used. This resulted in an initial required thickness
which was greater than the actual required thickness of the nozzle. The initial calculation
was more conservative than required. The required nozzle thickness was recalculated during
the Joint Review, and all components were determined to be within code requirements.
The welding procedures and practices used to fabricate the demonstration vessel were
examined to assure SPC’s adherence to code and the design drawings. The storage for the
weld media was inspected, and the weld procedure specifications (WPS) used on the vessel
were examined. A WPS is a formal written document describing welding procedures, which
provides direction to the welder for making sound and quality production welds as per the
code requirements. SPC’s applicable WPS’s were on file and removed for examination
during the Joint Review.

45
The vessel had received partial welding before the Joint Review. The heads, nozzles and
bracket had been tac-welded to the shell of the vessel. Seam welds had not been applied.
The AI checked the component alignment and surface preparations in the presence of the
examiner from the NBIC. After they were both satisfied with the work already
accomplished, they gave permission for SPC to perform a seam weld on the vessel. A
certified SPC weld technician applied a portion of the head to shell seam and a complete
nozzle to head seam. These welds adhered to the design and SPC’s WPS for that material
and shape. The joint review continued to review the design calculations while the welds
were accomplished, and returned later for inspection. The partially welded vessel permitted
the AI and examiner to inspect the interior side of the welded joint for complete penetration
at the weld root. They were satisfied with the quality of the welds performed, and they
continued with the joint review.
The Joint Review determined that SPC’s practices regarding pressure vessels
construction adhere to ASME code. This determination was made through the examination
of the shop’s QC manual, welding documentation, and sub-contracting requirements.
Additionally, the shop’s construction of the code compliant vessel design permitted SPC to
demonstrate that its fabrication practices adhere to code. Specialty Piping was permitted to
renew its ASME BPVC credentials with the signature of the examiner from NBIC.

46
TESTING
Preliminary testing of the vessel’s pressure retention capability commenced on the
evening of Sunday, January 26, 2014 at American Muscle Street Rods and Customs in
Loveland, Ohio. It was initially tested at an ambient temperature of 60°F. The vessel’s inlet
coupling was connected to a 100 psig shop air system. The outlet valve of the vessel was
closed and the inlet valve was opened slightly to allow the vessel to receive air pressure. Air
was applied until the vessel’s internal pressure reached 50 psig. At this point, the inlet valve
was closed to trap the pressurized air within the vessel. The vessel was observed in this
pressurized condition for 30 minutes to assure there was no leakage from the vessel, fittings
or valves. The vessel retained pressure for the time interval, and it was determined there was
no leakage.
An attempt was made to test the vessel at its design temperature and pressure. The
vessel was emptied of pressurized air, and then disconnected from the external air source.
Both valves were closed. The exterior surface of the vessel was heated using a propane
torch. Initially, the torch was continually moved over the surface of the vessel to evenly
distribute heat, and the surface temperature of the vessel was monitored using a laser
thermometer. However, the design temperature of 300°F proved difficult to obtain. The
vessel was heated using a propane torch designed for melting plumbing solder. This proved
unable to provide enough heat to sustain the required surface temperature. 300°F could be
reached at localized areas by allowing the torch to linger over one spot, but the temperature
could not be sustained or applied uniformly over the surface of the vessel. During both tests,
the vessel retained pressure as shown in Figure 43. It showed no signs of cracking or fracture
due to stress within the materials. However, the vessel needed to be retested to assure it
could retain design pressure at design temperature.
Figure 43 – Pressure gauge during pressure test.

47
The vessel was tested for a second time on Saturday, March 8, 2014 at the Little
Miami Golf Center (LMGC) in Newtown, Ohio. The grounds maintenance shop of the
facility offered 100 psi shop air and an acetylene torch. The acetylene torch, as pictured in
Figure 44, was able to provide the heat required to obtain and maintain the vessel’s surface
temperature at or above 300°F. Temperature measurement was accomplished with a laser
surface thermometer as can be seen in Figure 45. The vessel was pressurized to 50 psig and
heat was applied using the torch. Continual movement of the torch provided a uniform heat
distribution through the vessel. Fourteen minutes of heating were required to build the heat
on the vessel’s surface to design temperature. Heating continued after the desired
temperature had been obtained to maintain the design temperature. The vessel’s outlet valve
was opened slightly three times during the heating process to maintain the climbing pressure
at its design value. The vessel maintained 50 psig at 300°F for thirty minutes before the test
was deemed successful.
Figure 44 – Vessel heating using an acetylene torch.
Figure 45 – Temperature readings using a laser surface thermometer.

48
SCHEDULE AND BUDGET
SCHEDULE
This undertaking began in September 2013 with research regarding the requirements of
fabrications shops in gaining and maintaining ASME BPVC accreditations. Research lasted
into October, and it produced the basis for a proof of design document. The proof of design
establishes the criteria against which the project is judged.
Following research and the proof of design, design concepts were generated and then
evaluated. Several concepts were eliminated from consideration due to their expense or lack
of applicability to the potential customers’ expected work-scope. The final design concept
was determined to be a conventionally shaped and constructed pressure vessel.
In the beginning of November, Specialty Piping Corporation specified design criteria for
a demonstration pressure vessel. The vessel was to be built to fulfil requirements of their
Joint Review on December 19. A vessel design was generated with the knowledge of what
materials were available to SPC. Then, the design was analyzed according to the rules
presented in ASME BPVC Section VIII, Division 1. Specialty Piping received the design
and analysis calculations on November 25. Material was selected and removed from SPC’s
stock on Tuesday, December 10, 2013, and the initial steps of fabrication started that week.
The Joint Review occurred on December 19, 2013 at SPC’s facility in Davisville, WV.
The review was an all-day process, and it included fabrication procedures on the vessel. The
reviewers were satisfied with the weld processes before all welds were complete, so the
vessel was finalized over the course of the following three weeks. This period included two
shortened work weeks due to holidays.
The vessel was received on Wednesday, January 15, 2014. It was then fitted with inlet
and outlet valves, a pressure gauge, shop air adapters, and the fittings required to mate the
components. The added components prepared the vessel for preliminary testing, which
occurred on January 23, 2014. Final testing occurred on March 8, 2014. The vessel was
pressurized to design pressure at design temperature, and it was able to maintain its pressure
without fracture or signs of excessive stress. The vessel was then prepared for presentation.
This includes painting and attachment of the data plate, which occurred on March 17, 2014.
Appendix E presents the schedule with completion dates, academic submission dates and
intervals.

49
BUDGET
Material costs are divided into two categories. The first contains the costs incurred by
SPC for the vessel components assembled and welded for the purpose of their Joint Review.
The seconds includes the costs of the hardware used to fit the vessel to an external system for
testing and presentation.
SPC provided the shell, heads, nozzles, C-channel and weld media required to produce
the form of the vessel. Additionally, they provided the labor and expertise to weld the
components together. The material costs for the fabrication shop totaled under $200. The
exact amount of weld media required to fabricate the vessel is difficult to determine, but an
estimated cost of $20 is appropriate to cover the cost of one roll of weld media.
The valves, fittings, adapters, tees, gauge, data-plate and paint were not provided by
SPC, but were applied and installed for testing and presentation. These materials are
available at most hardware stores, and their costs are relatively small. The total cost of these
materials is slightly more than $100.
The largest expense associated with earning or maintaining ASME accreditations is the
costs associated with the Joint Review. The AI, Code Services Supervisor, and examiner
each have an associated cost of between $1000 and $1500 a day, and their services are
required for at least two days. One day is for in-process inspections and review of the QC
manual, and the second day is for the Joint Review. Additionally, fees to ASME for
registration and certification may easily reach well over $1000 depending on the stamp and
designators. Joint Review and certification costs range from five to ten thousand dollars.
These costs are incurred by the shop seeking accreditation.
Typical design and calculation services range from $600 to $900 for a demonstration
vessel. The cost varies according to the complexity and size of the required vessel. In this
case, Specialty Piping was not charged for engineering services in exchange for the vessel.
Material costs are presented in Appendix F.

50
CONCLUSION
The ASME BPVC constitutes 13 volumes and totals over 17,000 pages, but fabrication
shops need only be certified in the portions of the code that relate to their work-scopes. This
results in 21 possible certifications which ranges from miniature pressure vessels
construction to nuclear process piping inspection.
The demonstration pressure vessel plays a large role in ASME BPVC certification for
fabrication shops seeking pressure vessel construction accreditation. This certification is
indicated on pressure vessels with a “U” stamp surrounded by a 4 leaf clover symbol. The
demonstration vessel is only one part of a substantial process. To earn accreditation for
pressure vessel construction, a fabricator is required to produce a compliant Quality Control
Manual and demonstrate a Quality Control System. Traceability is required of all materials
used for fabricating ASME compliant equipment, and certifications are required of
fabrication technicians. The demonstration vessel serves as a vehicle to demonstrate these
requirements during a Joint Review, and it is vital to the process.
The primary concern when designing an ASME demonstration vessel is that it is code
compliant, and its compliance is proven with code calculations. Compliance ensures safety,
and other features constitute lesser importance. Mathematical analysis is required of each
pressure retaining component to safely withstand the stresses of applied pressure.
Furthermore, the means by which the components are joined require adherence to code and
mathematical analysis. Therefore, the design of a vessel is accompanied with a calculation
packet, which proves the design’s adherence to code.
Construction of the vessel begins before the Joint Review with an Authorized Inspector
present. The AI reviews the design for code compliance, then reviews the material for
traceability. Hold points are designated in the vessel’s traveler to indicate processes to be
witnessed by the AI and the Joint Review Board. This board includes an examiner from the
National Board of Boiler and Pressure Vessel Inspectors. In this case, the vessel components
were tac-welded before the Joint Review, and some seams were completed and inspected
during the Joint Review. The review board was satisfied with the fabricator’s systems before
the vessel was fully welded. The board was convinced that the fabricator’s quality control
and construction practices adhered to code, so the shop was permitted to renew their “U”
stamp with “W” designator certification.
Welding was completed after the Joint Review to test and present the vessel as a
demonstration vessel. Following the completion of welds, the vessel was fitted with
couplings, valves and a gauge. These components facilitated pressure testing to assure the
vessel met its design parameters. The vessel met its design requirements without evidence of
damage due to stress caused by applied pressure. Paint and a data-plate were applied to the
vessel for presentation purposes, because this vessel will not see industrial use. However, if
this vessel were registered and applied to industry, it would meet all American Society of
Mechanical Engineers Boiler and Pressure Vessel Code requirements for a vessel designed at
its specific operating temperature and pressure.

51
The time and expense dedicated to ASME certification ensures that fabrication shops
produce safe pressurized equipment.

52
WORKS CITED
1. ASME. ASME Boiler & Pressure Vessel Code - An International Code. asme.org.
[Online] 2013. [Cited: 08 27, 2013.]
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2. Smith, Carlisle R. Building you first ASME code vessel, start to finish.
thefabricator.com. [Online] July 16, 2013. [Cited: August 22, 2013.]
http://www.thefabricator.com/article/arcwelding/building-your-first-asme-code-vessel-start-
to-finish.
3. The American Society of Mechanical Engineers. Guide for ASME Review Teams for
Review of Applicants for ASME Certificates of Authorization (A, M, PP, S, E, V, HV, H,
HLW, H (Cast Iron/Cast Aluminum), UD, UV, UV3, U, UM, U2, U3, RP, T, TD, TV).
asme.org. [Online] August 2011. [Cited: August 26, 2013.]
http://files.asme.org/asmeorg/codes/certifaccred/certification/810.pdf. A1.20-8/11 .
4. ASME Boiler and Pressure Vessel Committee on Pressure Vessels. 2010 ASME Boiler
& Pressure Vessel Code Section VIII Division 1. New York : American Society of
Mechanical Engineers, 2010. 56-3934.
5. ASME Boiler and Pressure Vessel Committee on Materials. 2010 ASME Boiler &
Pressure Vessel Code, Section II Part D . New York, NY : American Society of Mechanical
Engineers, 2010. 56-3934.
6. Pressure Vessel Engineering. Design Calcs Sample - Audit Vessel. pveng.com. [Online]
April 5, 2012. [Cited: August 26, 2013.]
http://www.pveng.com/ASME/ASME_Samples/Audit/Audit.php. PVE-5918.
7. Hearn, EJ. Mechanics of Materials 1, An Introduction into the Elastic and Plastic
Deformation of Solids and Structural Materials - 3rd Edition. s.l. : Butterworth-Heinemann,
1997. ISBN 0-7506-3265-8.
8. Mahmud, Arshad. Pressure Vessels Ensure Safety. asme.org. [Online] August 2012.
[Cited: 08 29, 2013.] https://www.asme.org/engineering-topics/articles/pressure-
vessels/pressure-vessels-ensure-safety?cm_sp=Pressure%20Vessels-_-
Feataured%20Articles-_-Pressure%20Vessels%20Ensure%20Safety.
9. Ridle, William. ASME Code Pressure Vessels. Medina, August 20, 2013.
10. Didion, Don. Operator of Didion's Mechanical. Bellevue, 9 3, 2013.
11. MID. Rectangular/Square Process Vessels. Thermosetfrp. [Online] MID. [Cited: 12 9,
2013.] http://www.thermosetfrp.com/product1.html.
12. CTCI Machinery Corporation. All Products. [Online] All Products, 2013. [Cited: 12 9,
2013.] http://www.allproducts.com/tami/ctci-kfs/07.html.
13. Composites World. Next Generation Pressure Vessels. [Online] Gardner Business
Media, Inc, 2013. [Cited: 12 10, 2013.] http://www.compositesworld.com/articles/next-
generation-pressure-vessels.
14. Caps & Heads. Act On. [Online] ACT Inc. [Cited: 12 10, 2013.] http://act-
on.ca/acton/Product/Cap%20&%20Head.htm.
15. Home. Specialty Piping Corp. [Online] Kaslo Design. [Cited: 12 10, 2013.]
http://specialtypiping.com/pipefab.htm.
16. Pipe Chart. All Steel Pipe. [Online] 2013. [Cited: 12 10, 2013.]
http://www.allsteelpipe.com/Pipe-Dimensions-Weights-Chart.pdf.
17. Baker Tankhead Incorporated. Tank Heads. Baker Tankhead. [Online] 2013. [Cited:
12 11, 2013.] http://bakertankhead.com/products/tank-heads.htm.

53
18. Head Types. Dished Heads. [Online] Dished Heads, 2011. [Cited: 12 11, 2013.]
http://dishedheads.com.au/documents/1601-Head-Types.
19. Butt Joints. TPUB Integrated Publishing. [Online] TPUB. [Cited: 12 11, 2013.]
http://constructionmanuals.tpub.com/14250/css/14250_51.htm.
20. Unknown. T joint pipe weld. Weldsmith. [Online] [Cited: 12 11, 2013.]
http://weldsmith.co.uk/tech/welding/learn_proc/pipe/stl_SMA_0605/pipe_t.html.
21. Ferguson Enterprises. Figure 410A Brass Body Ball Valves. FNW Valve. [Online] 8
2012. [Cited: 12 11, 2013.]
http://www.fnwvalve.com/FNWValve/assets/images/PDFs/FNW/FNW_Fig.410A.pdf.
22. Home Depot USA. Mueller Global 1 in x 12 in Galvanized Steel Nipple. Home Depot.
[Online] 2013. [Cited: 12 11, 2013.] http://www.homedepot.com/p/Mueller-Global-1-in-x-
12-in-Galvanized-Steel-Nipple-565-120HN/100194453#.UqjDSroo6cw.
23. Shinnecock Hardware. Ace fittings 511-941BG Galvanized Iron Hex Bushing 3/4"
MIP. Hardware to Go. [Online] Dotcomweavers, 2010. [Cited: 12 11, 2013.]
http://www.hardwaretogo.com/product/bushing-hex-galv-34x14.html.
24. —. Mueller Industries 510-754BG Malleable Iron Galvanized Reduc. Hardware to
Go. [Online] Dotcomweavers, 2010. [Cited: 12 11, 2013.]
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25. Spotts, M.F. Design of Machine Elements, 8th Edition. Upper Saddle River : Pearson
Prentice Hall, 2003. 0130489891 .
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27. Grainger. Coupling, 1 In., Socket Weld. Grainger. [Online] 1994. [Cited: January 20,
2014.] http://www.grainger.com/product/Coupling-1MNX2?functionCode=P2IDP2PCP.

54
APPENDIX A – RESEARCH
Interview with design engineer: William Ridle of Southport Services.
3326 East Smith Rd. Medina, OH 44256 08/20/13
William Ridle has over forty years of engineering experience ranging from automobile
tire production to environmental protection and monitoring equipment. He started
Southport Services in 1986 to provide engineering support to small fabrication shops, and
he has supplied ASME code design packages since 1989.
The primary concern for all pressure vessels is that they are safe. Safety is ensured by
adherence to ASME code. Pressure vessels must be designed within the confines of the
code. The vessels must be constructed of approved and traceable materials. Weld material
must be approved and traceable. Welders must be certified.
Customers provide design conditions for their required pressure vessel, even demonstrator
pressure vessels. These conditions typically include operating pressures, temperatures,
environments, and size requirements. The role of the engineer is to design the appropriate
pressure vessel in accordance with ASME code. The customer, or fabricator, is
responsible for building the pressure vessel with approved materials and certified
personnel. A third party inspector reviews the design and inspects the vessel, during and
after construction, to assure it adheres to code.
Interview with fabrication shop owner Don Didion of Didion’s Mechanical
1027B County Road 308, Bellevue, OH 44811 09/03/13
Don Didion has operated Didion’s Mechanical for 37 years. The business started with the
fabrication of process piping. The company pursued ASME accreditation for pressure
vessels in 1989 and has maintained its accreditations since. Currently, 99% of this
company’s business centers on fabricating pressure vessels, boilers and heat exchangers
within compliance to ASME code. Didion’s Mechanical holds accreditations for Section
VIII, Divisions 1, 2 and 3 of ASME’s Boiler and Pressure Vessel Code.
Typical pressure vessels, including demonstrator pressure vessels, must be built to adhere
to Section VIII of ASME’s Boiler and Pressure Vessel Code. To ensure adherence;
 They must meet ASME Code
 Design package must have ASME Code Calculations
 The vessel must be accompanied by an in-plant traveler during fabrication
 Include fit-up-points for the AI to witness assembly and welding
 Typical construction;
1. Shell – body of vessel (often a large diameter schedule 40 pipe).
2. Head – convexed end (often a casting).
3. Caps – disks welded into one end.
4. Nozzles – typically 2, inlet/outlet, often with a relief valve.
 Paperwork must be organized and retained for at least 5 years.
ASME Accreditation is expensive. Didion’s Mechanical spent $35,000 to maintain
accreditations in 2013.

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