Modular Casing for

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					University of Delaware
126 Spencer Lab
Newark, DE 19716
December 10, 2005


Dear Speakman,
Attached you will find our final report for the University of Delaware‟s Senior Design Project. In
it we have detailed the design of a new Safety Shower System for Speakman Company‟s SE-
6000 shower unit. We have enjoyed working on the project and are extremely pleased with our
results; we are confident that we have delivered a design meets your specifications, and stands up
to your company‟s overall reputation.

Over the course of this project we worked with Imants Stiebris, Russ Waters, Graham Paterson,
C.P. Donovan, Mark Puzzo, and Nancy Paradis from the Speakman Company, as well as our
advisor, Nate Cloud of the University of Delaware‟s Department of Mechanical Engineering.

We have validated our system design by the delivery of a full-scale prototype and strongly feel
that this system will greatly improve the sales of Speakman‟s safety shower units as well as
decrease the cost and assembly time of the shower system. Please feel free to contact us if you
have any questions or recommendations.

Sincerely,
Team 1
Mike Fuqua            mfuqua@udel.edu
Colby Janisch         colbyjanish@yahoo.com
Ryan Kobos            rkobos@udel.edu
Steve Opsitnick       udlax24@hotmail.com
Joey Tordella         tordella@gmail.com
 Modular Casing for
Outdoor Safety Shower

  Team Speakman:
     Mike Fuqua
    Colby Janisch
     Ryan Kobos
   Steve Opsitnick
    Joey Tordella




                        1
                                                   Table of Contents


Executive Summary ........................................................................................................................ 3
Introduction ..................................................................................................................................... 4
Previous Work Leading up to Detailed Design and Prototype ....................................................... 4
   Wants .......................................................................................................................................... 4
   Metrics ........................................................................................................................................ 5
   Benchmarking ............................................................................................................................. 6
     Competition Design Benchmarks ........................................................................................... 6
     Technology Benchmarks ........................................................................................................ 8
   Concept Selection ....................................................................................................................... 9
   Shell Design .............................................................................................................................. 12
     Lower Section ....................................................................................................................... 13
     Middle Section ...................................................................................................................... 14
     Top Section ........................................................................................................................... 15
     Insulation............................................................................................................................... 16
     Sealing Methods.................................................................................................................... 16
Prototype ....................................................................................................................................... 21
Cost Analysis ................................................................................................................................ 24
Path Forward ................................................................................................................................. 26
   Appendix A: .............................................................................................................................. 28
     UDesign Spreadsheets .......................................................................................................... 28
   Appendix B: .............................................................................................................................. 32
     Manufacturing Costs ............................................................................................................. 32
   Appendix C: .............................................................................................................................. 33
     NPV comparison ................................................................................................................... 33
   Appendix D: .............................................................................................................................. 35
     Material properties comparison ............................................................................................ 35
   Appendix E: .............................................................................................................................. 36
     Competition Specs ................................................................................................................ 36
   Appendix F: .............................................................................................................................. 38
     Parts List ............................................................................................................................... 38
   Appendix G: .............................................................................................................................. 39
     2-d Dimensioned Solidworks Drawings of Shell.................................................................. 39
   Appendix H: .............................................................................................................................. 45
     Thermal Expansion Equations .............................................................................................. 45




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Executive Summary
        Speakman Company produces a line of safety products that include safety showers,
emergency eye washes, and drench hoses. Speakman‟s solution to provide outdoor safety
showers is the SE-6000 Heat Traced Decontamination Station. This product is a safety shower
with heat traced tape wrapped around the galvanized steel piping, insulated to further protect it
from extreme temperatures, and then sealed shut in PVC piping to make the shower water tight.
This product is difficult to assemble and nearly impossible to take apart once assembled; to
remain competitive in the marketplace, our team has worked with Speakman to improve the
design of this product. We, with Speakman‟s help, determined that the outer casing is the part of
the shower with the most room for improvement. Through research and benchmarking, we
determined that the best way to improve the shell is to use a vacuum formed ABS plastic shell,
similar to the competition. Once we determined this, we broke the shell down into various
subsystems: the method for sealing the halves together, the method for creating a water tight seal
around the holes in the shell created by protrusions, the design of the shell itself, and the
insulation. Using various testing procedures and researching standards, we decided to seal the
shell with an internal EPDM foam rubber gasket and to hold the halves of the shell together with
nylon rivets. We will seal the protrusions from the shell made by the water supply pipe, shower
head, etc, with lip style rubber grommets. For insulation, we will use a pre-slit, self-sealing,
closed cell Aramacell piping insulation. This insulation has thermal properties identical to
Speakman‟s current insulation.
        We justified all of our design decisions through a systematic comparison of the key wants
and metrics that we identified after defining the problem. With a completed design, we further
validated our concept with various prototyping methods, such as an actual life-size prototype
created by a thermoformer and rapid prototypes with a 3-d printer. With further work done over
the winter to finalize our system, Speakman will be able to start production beginning sometime
in 2006.




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    Introduction
            Speakman Company introduced the first emergency shower in 1939, and since then have
    developed a line of safety products that include safety showers, emergency eye washes, and
    drench hoses. They also produce a range of combination units, one of which is a Heat Traced
    Combination Decontamination Station: the SE-6000. This safety shower/eye wash combination
    unit is freeze protected, allowing it to function outdoors under conditions that a normal safety
    shower would not handle. The SE-6000 is available with optional add-ons: a freeze protection
    valve, a scald protection valve, a flow switch, an area light, alarms, a conversion to allow for top
    supply of water, a drench hose, and an immersion well thermometer.
             Speakman would like to improve the design of the SE-6000. It currently consists of a
    galvanized steel pipe shower frame, which is wrapped with heat traced cable and insulation to
    protect it from freezing, and encased in 3” PVC piping for protection from the elements and
    impact.
            After we analyzed the current unit and those of various competitors, we, along with our
    contacts at Speakman, found that the outer shell is the component that needs the most
    improvement. The current shell is very strong, weather proof and durable, but is difficult and
    time-consuming to assemble, and is nearly impossible to take apart for maintenance. The new
    design for the outer shell has to retain all the positive aspects of their current product, while
    providing additional benefits, such as modularity, ease of assembly and maintenance, and a
    lower cost.
            Some of Speakman‟s competitors (See Appendix E) use a molded plastic shell to encase
    their steel piping and insulation; to maintain competitiveness within the market, we decided that
    their outer shell should be similar in design.
            Our team has developed a detailed design that will improve their SE-6000 in terms of
    cost, assembly time, and ease of maintenance. This design includes engineering drawings
    detailing the shape of the shell, the material the shell will be made of, the method of sealing the
    shell together, a method for sealing the protrusions of the shell (such as the eye wash and shower
    head), and an improved type of insulation.
             With the finalized design, we approached our selected thermoforming company, and
    with Speakman‟s approval asked to have a full scale prototype created. Now that we have the
    prototype we are able to assemble our entire system with all of its included subcomponents
    (selected gasket material, fasteners, insulation, etc.) over the existing steel pipe frame to validate
    our design.
             This report will show what decisions were made to determine this design, and the
    justifications of these decisions leading to the delivery of a full scale prototype and completion
    of our team goal of creating an improved safety shower system.


Previous Work Leading up to Detailed Design and Prototype
    Wants
            In order to improve the design of the SE-6000, Speakman provided us with a list of
    wants. The shower must be easy to assemble, and have easy access to different sections for
    maintenance. The design of the shower should be modular; that is, there has to be one design
    that will accommodate all the options, such as a freeze protection valve, a scald protection valve,


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alarms, and a flow switch. In addition to accommodating options, the shower should be capable
of being adapted for the three different mounting styles available: floor, buried water supply, and
wall mounted. Speakman has also expressed a desire to have the shell material pre-colored
instead of painting their “safety green” on to the outside of the shell.
        The majority of these wants can be obtained by modifying the current shell of the SE-
6000. Therefore, the most effective method to achieve these characteristics in the overall shower
is to design a new casing system.
        We constructed a list of customers that will be affected the most by these changes in the
design. These customers included northern climate users, factory workers, maintenance workers,
and southern climate users. We then ranked the customers in terms of importance and created an
ordered list of our top ten customer wants, shown below (figure 1).
        Although cost is an important want, these list shows weather proofing ranked above it.
Weather proofing is more important that cost because if the outer casing of the shower does not
meet the requirements for being weather proof, the shell can not be used on the shower
regardless of how much it costs. The other wants below cost, such as durability, multiple
options, and ease of assembly, are not necessary for the outer casing to function, and thus are
ranked below cost.

                              Wants                     Relative
                                                      Importance
                        weather proofing                  26
                               cost                       17
                            durability                    17
                         multiple options                 16
                        ease of assembly                  10
                          easy access                      5
                           aesthetics                      3
                               paint                       2
                         minimal pieces                    2
                         non hazardous                     1
                               Figure 1: Top ten Customer Wants




Metrics
         Once the wants were ordered by importance, we derived a set of quantifiable metrics that
correlated with these wants, and established target values that the design must meet in order to
fulfill the design requirements. In order to determine which metrics were the most important, we
used UDesign (a design tool that can be used to compare concept ideas and aid in concept
selection) to rank the metrics based on how strongly they correlated to the wants while taking
into account the importance of each want. The result of this procedure is shown below (figure
2). This list of ranked metrics enables us to quickly compare different concept ideas and
determine what concept is most likely to meet all the wants and needs of the customers and
Speakman Company.




                                                                                                 5
                           Metrics                            %
                           Cost                               14.32
                           Water tightness                    12.16
                           UV resistant                       11.59
                           Temperature range                   11.51
                           Assembly time                       11.47
                           Thermal conductivity                10.59
                           Number of options                    7.73
                           Number of pieces                     7.58



                                  Figure 2 – Ranked Metrics



Benchmarking

               Competition Design Benchmarks

        Upon determining the scope of the problem and defining key metrics and target values,
we looked to see what Speakman‟s competition in the marketplace had chosen to do for their
outdoor showers. We noted three companies who were producing products similar to Speakman.
These companies, Bradley, Haws, and Encon, have all chosen to pursue a similar design
solution. There are several other safety shower competitor companies, however only these 3
companies produce heat traced units comparable to the SE-6000. The designs of the 3
competitor‟s products are all very similar to each other. The common features consist of vacuum
molded plastic panels, which are placed around the internal piping and insulation with the seams
running along the front and rear of the unit. These panels are then connected through the use of
an elastometric seal; a metal backed rubber clamshell gasket. An example of one of these
products is shown below.




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        Figure 3: Vacuum molded plastic shell with external gasket, used by competition

        Upon inspection of one product, we found that the seal had fallen off in transit from
manufacturer to customer. This was due to the fact that the current seals of the competition are
not formally attached to the paneling, but rather simply pressed on to the lip created by the seams
of the two halves. Due to this weak sealing method, we determined that this seal showed the
most room for improvement.
        The first competitor that we investigated was Bradley. Speakman allowed us access to the
Bradley unit for comparison, which proved very helpful in identifying features we liked and
disliked. There were several components we liked about this particular unit such as the ability to
add and remove options without changing out panels. Bradley has the panels pre-molded for a
fully-loaded shower unit, and models without all added features are simply given plugs to cover
the holes where the optional parts would go. Also, this unit uses vacuum molded ABS plastic
panels as the shell material. This seems to be one of the more promising methods for creating
these shells, as all 3 competitors use vacuum molded panels. Lastly, the junction box on the
Bradley unit accepts a trio of options, which is much more simplified than that of the Speakman
SE-6000, which has a junction box that only accommodates one option. We determined through
this research that we needed a more compact junction box on the new model.
        Our main dislike of the Bradley unit is the sealing method; it uses the clam-shell style
seal mentioned above to hold the two halves of the shell together. This is also the unit that
arrived with one piece of the seal material lying in the bottom of the box and the two halves of
the panels were lying open inside the box. The seal is attached to the panels by an interference
press fit. The seal itself has a sheet metal backbone which is bent to be undersized, then
extruded with the rubberized liner surrounding it, and cut to size. This is then simply pushed by
hand onto the seam created by the two lips from the plastic shell panels. We feel that this
method has already been proven to be inadequate because the seal can‟t even hold up to
shipment, let alone being in a harsh outdoor environment for a long period of time. Furthermore,


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the Bradley unit is not completely water or weather tight. The rubber grommets used around the
eye wash and drench shower do not create a tight seal around the piping, allowing for anything
from water to debris to enter the inner portion of the unit.
        The next competitor investigated was the Haws Company. Their product is quite similar
to the Bradley unit in many ways, including the vacuum molded shell panels, and same
rubberized clam-shell style seal. The Haws unit is advertised as being water proof and weather
proof; however, since it uses the same sealing method as the Bradley unit, this claim is
questionable. The Haws and Bradley units also share the same foam insulation material.
        We investigated the Encon unit last. The unit is currently the higher end model of safety
showers on the market due to its wide variety of available features and hefty price tag. Several
features of this unit are very attractive, starting with the 8 piece design of the outer shell (twice
the amount of pieces of the other two competitor‟s units). We believe that the main reason for
the 8-section paneling is to allow the unit to be converted from a floor mounted shower to a wall
mounted shower without the need for custom shell panels for each type of mounting. If the
customer requests a wall mounted unit, the panels below the eye wash are simply left off, and a
cap is installed to reseal the shell. Like the other units, Encon‟s also allows the ability to add and
remove options without the need for new shell panels, by once again pre-drilling the panels for a
fully-loaded unit and then capping the unused holes off with rubber caps.
        By simple inspection of the Bradley unit and assuming that the Encon unit uses the same
grommets, it is likely that water will enter the inside of the shower shell during use. Not
surprisingly, the Encon unit once again uses the same clam-shell style seal used by the other 2
competitors. See Appendix F for pictures and comparison of the three competition benchmarks.


            Technology Benchmarks

         After looking at the competition, we noted that all the companies employ the use of a
molded plastic shell. To determine the best method of molding a plastic shell, we researched
various molding methods. We investigated manufacturing with six different molding techniques:
vacuum-forming, injection molding, compression molding, structural foam, and rotational
molding.
         Vacuum-forming is performed by taking a sheet of thermoplastic and heating it up so that
it is pliable. Once softened, a solid mold half is pushed up into the plastic, and then a vacuum is
pulled through the mold, causing the thermoplastic to adhere to the shape of the mold. The part
is then removed, yielding a good tolerance to the desired output form, yet maintaining uniform
thickness. The properties of the part will then solely depend on the plastic being used. Therefore,
one can obtain all properties necessary such as water resistance, UV protection, damage
resistance, and heat/cold resistance.
         Injection molding involves the heating of plastic pellets until they become molten plastic.
The plastic is then injected into a mold, and left to cool for the necessary amount of time. The
plastic cools and hardens in the desired shape. This process is very efficient, but also expensive.
If Speakman intended to manufacture thousands of safety showers per year, injection molding
would be highly favored. Since the target production is in the vicinity of four hundred, this
process may be too expensive.
         In compression molding, powder-liquid mixtures are placed within the chamber of a
mold, and then compressed by a heated plug that is located above the mold. The plug heat treats



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the mixture and compresses it to the desired shape. This process is ideal for plastics, and is very
time efficient. Unfortunately, the cost is also very high.
        Structural foam is a low pressure injection molding technique. This method is cheaper
than injection molding because less resin is used and the molds can be made of cheaper products
due to the low pressure. The resin is mixed with a foaming agent and then injected into the
mold. In this process, less resin will be injected into the mold as compared to other injection
molding processes because there must be room for the foam to expand. This foam provides a
high stiffness to weight ratio, excellent electrical and thermal insulating properties, damage
resistance, very low water absorption, and UV protection. However, this may be significantly
more expensive then vacuum molding.
        Rotational molding is a process used for producing hollow plastic products. It is different
from other molding techniques in that the heating, melting, shaping, and cooling stages all occur
after the polymer is placed in the mold, which means that no external pressure is applied during
forming. The polymer powder is placed in the mold, and then the mold is closed and put into an
oven. Inside the oven, the mold is rotated around two axes. As the powder becomes harder, it
begins to melt and stick to the inner walls of the mold. The mold is then cooled and opened.
This is a slow process that yields low cost prototypes.



Concept Selection
        Through research and benchmarking the competition, we developed three concept ideas
that meet the design requirements that Speakman gave us, and analyzed them to test their
validity. The first concept examined was the clamshell style shell seal used by the various
competitors. It involves a molded ABS plastic shell with an edge lip. The two halves of the
shell are sealed together with an external rubber gasket backed with sheet metal. The advantages
of this concept are that it is relatively simple to design, easy to assemble, and the external gasket
provides protection against the sharp edge that exists as a result of the lip. However, this
external gasket is fairly expensive ($2.20/ft), and the overall appearance of the shell is not
aesthetically pleasing. Also, the external gasket doesn‟t give a completely water tight seal, and
did not secure the shell pieces together as well as was necessary. A picture of this concept is
shown below.




                Figure 4– picture of Bradley unit showing external gasket concept



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        The second concept we considered was a molded ABS plastic shell with an edge lip that
is sealed with an internal foam rubber gasket, and fastened together with a nut and bolt. This
concept retains the advantages of easy design and assembly, while reducing the cost of the
gasket, and making it more water resistant. However, since there is no external gasket to cover
up the lip, the edge of the shell where the two halves join together is sharp, and poses safety
problems. To avoid this safety problem, we could coat the sharp edges with a soft foam, which
would add to the cost of the overall shell system. Shown below is a picture of this concept.




                     Figure 5 – picture of lip style shell with internal gasket

        The final concept we considered is a molded ABS plastic shell that fits together by
having overlapping edges, and is sealed with a foam rubber internal gasket placed where the
edges overlap, and fastened using nylon rivets. This idea is not significantly more costly than the
second concept alternative, and the problem of sharp edges is not an issue because the
overlapping edges create a round appearance. Additionally, the overlapping edges make it
harder for water to get in. This, coupled with an internal gasket, makes the shell completely
water tight. This concept is shown the figure below.




                         Figure 6 – Picture of overlapping edges concept




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        For all three concepts, the material used for the shell is ABS plastic. The ABS was
chosen because it maintains its mechanical strength and stiffness while being vacuum-formable
and UV resistant, which are characteristics shared by few other plastics. Of these, ABS is one of
the cheapest. We chose to use the vacuum-forming method for all three designs based on
discussions with several plastic fabricators who suggested that the process would be the best
method for our particular application; the cost of vacuum-forming is less than the other options
for the low production rates of the SE-6000.
        These three concept ideas were compared in UDesign and rated against our top metrics in
order to determine the best concept. In terms of cost and water tightness, both the internal gasket
seal with a lip edge concept and the overlapping edges concept are better than the initial external
gasket concept. All three concepts are equally UV resistant and have an acceptable operating
temperature range. The characteristics that set the third idea apart from the other two were the
reduced assembly time and the absence of sharp corners. Because of these advantages, we
decided that the best concept for this project is to create a molded ABS plastic shell with
overlapping edges that are sealed with an internal gasket and nylon rivets. This decision was
verified after discussing the various alternatives with our contacts at Speakman. In order for this
concept to have low assembly and disassembly time, we determined that the shell should have
three sections – a lower section extending from the bottom of the shower to beyond the eyewash,
a middle section extending from the top of the lower section past the drench hose option, and a
top section oriented horizontally to accommodate the shower head and the optional scald valve.
Designing the shell with three sections provides an optimum solution to the trade-off between the
cost of the mold and ease of assembly and maintenance. The more sections the shell has, the
easier it is to perform maintenance and assemble the shower. However, more sections raise the
tooling costs significantly. Three sections allows for relatively easy assembly, while still
keeping the costs lower than they would be with four sections.

                                                                    Benchmark    A       B        C
               Metrics                        %      Target value
                           Cost              14.32      $250           0.2        1       1      -1
                      Water tightness        12.16       1.0           0.2        1       1       1
                        UV resistant         11.59       1.0           0.2       0.2     0.2     0.2
                     Temperature range       11.51   -50 to 150 F      0.2       0.2     0.2     0.2
                      Assembly time          11.47     15 min          0.2       0.2      1      -1
                    Thermal conductivity     10.59    = current        0.2       0.2      1      0.2
                     Number of options        7.73       5.0           0.2       0.2     0.2     -1
                     Number of pieces         7.58       6.0           0.2        1       1      -1
                           Volume            3.59     = current        0.2       0.2     0.2     0.2
                         Weight              3.25     = current        0.2       0.2     0.2     -1
                           Color             2.40     = current        0.2       0.2     0.2     0.2
                  Number of reusable parts   1.70     = current        0.2       0.2     0.2      -1
                     Elastic modulus         1.21     = current        0.2       0.2     0.2      1
                  Number of sharp corners    0.89         0            0.2       0.2     1       0.2

               Better than benchmark                                             3       6        2
               Worse than benchmark                                              0       0        6
               Same as benchmark                                       14        11      5        6
               Unknown relationship                  Sum-Up
                             Score                                    20.00     47.25   65.61   -24.57
      Figure 7 – Comparison of concept ideas. Benchmark is the external gasket concept,
         A is the lip seal with internal gasket, and B is the overlapping edges concept.

       The decision to create a modular ABS plastic shell with an internal gasket brought a
necessity to create a design that would be both aesthetically pleasing as well as functional. In


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order to accomplish this, our team separated into two sub-teams; one whose main focus was on
the aesthetics and dimensional designing, and the other whose main focus was to ensure the shell
maintained conformity to weather resistance requirements. The first sub-team created 3-d
models of the shower shell in solid works.




                              Figure 8 – assembly of shower shell.



Shell Design
        Our shell design incorporates an internal gasket and mechanical fasteners, eliminating the
need for the external flange and compression gasket used by all of our competitors. In the new
design, the two shell halves have corresponding male and female sides. The two sides overlap
with the internal gasket, sandwiching it in between to create the weather tight seal. The overlap
area creates a ¾ inch flat on the round shell to allow installation of the fasteners and placement
of the gasket. The width was chosen to ensure that there exists adequate area for the gasket to
seal against, while still allowing for the placement of the fasteners without water leakage. Holes
will be drilled into this overlap to allow for the placement of nylon push rivets to connect the
shell halves, holding the shell securely together. This method of internal gasket and overlapping
shell halves also allows virtually no water to collect on the shell seam. This allows the shower to
meet NEMA standards for freeze protection, an important consideration due to the operating
environments the shower is used in.
        The use of an internal gasket did cause a problem where the sections of the shower shell
should come together, however. If the sections are simply placed together along the edges, the
seam is not weather tight. To solve this problem, the shell sections actually overlap in the
vertical direction as well, with the same male and female correspondence. For example the
middle shell section has a 3 inch male extension on the top and the mating top piece is simply
cutoff as normal. The extension then slides into the top section upon assembly creating a


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weather tight seal. The transition can even have gasket material installed to ensure that the seal
between sections is water tight. This procedure may involve more assembly time than we
originally planned on, but it will still have lower labor costs and assembly time than the
procedure Speakman currently follows.
        A detailed description of the shell sections are explained in the following sections:


             Lower Section
        Beginning from the bottom of the shower, the first protrusion that needs to be sealed and
protected is the bottom water supply. To take care of this standard option, we will use a
grommet to ensure a weather tight seal. The grommet is placed in the end of a cylinder with a
flat vertical face provided by the two sides of the lower section coming together. The cylinder
was extruded out from the shell to protect the heat trace cable that runs along the pipe to keep the
incoming water from freezing. Figure 9, shown below, details this assembly.




                    Figure 9 – Solidworks drawing of water supply protrusion

         The next protrusion happens at the end of the eyewash section. To keep everything
encased, another cylinder with a spherical end must be molded onto this section. On this section
of the pipe there is a freeze protection valve, eyewash bullhorn, and eyewash drain. We decided
to make all of the inline to cut down on parts and curves in shower shell. The freeze protection
valve is the first part on this section of piping that needs to have the ability to drain water from
the piping if the water gets below a desired temperature. To incorporate this opening, a semi
circle was cut out of both halves and then sealed with the use of a grommet. The next cut out
needed is on the top of the pipe where the eyewash bullhorn sits. This is possibly the most
critical section that contains a grommet because it is going to be the area with the most direct
contact from water and has the possibility of having stagnant water lying on top. To seal this
properly, the bullhorn will have a rubber washer around the threads of the pipe that is tightened
down onto a flat horizontal surface. The flat surface will be obtained by having a cylinder
protrude slightly from the surface with a small hole tooled by the manufacturer to form a
tolerance fit around the pipe. To work the eyewash you have to use a paddle handle located 90
degrees from the bullhorn where another standard hole is needed. This hole must have a
grommet to insure a good seal, which will be inserted at the end of the extruded cylinder. The
final piece on this pipe that needs an exit point from the shell is the drain for the eyewash after it
is used to get rid of the extra stagnant water. This is going to be done by placing a small piece of
threaded PVC into the drain and extending it down about 2 inches. This PVC doesn‟t have to be
heat traced, thus allowing the shell to have another tolerance fit with a grommet for protection
from the elements.



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                  Figure 10 – Shell drawings of eyewash section of the shower



            Middle Section
        The next components of interest were the thermometer and the drench hose. The mold
needed to incorporate both a round cylindrical protrusion (towards the left) and a rectangular
protrusion (towards the right), as demonstrated in figure 11 below. The left protrusion is
designed to include the thermometer into the shower. The thermometer is not part of the
standard design; it is an additional option that is not used very frequently. However, since some
consumers do incorporate the thermometer, it needed to be a part of the shell design.




                    Figure 11 – Solidworks drawing of shell accommodating
                             drench hose and thermometer options




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        To incorporate the thermometer, we designed a cylindrical protrusion encasing where the
thermometer would be up to the point where the gauge rests (Figure 9). The surface closest to
the gauge is closed and flat. This makes for a watertight seal when the option is not there, as
well as a good drilling surface when the option is present. If a consumer wanted the option to be
there, Speakman Company would simply drill out a hole large enough for the thermometer to be
screwed on. The hole would then be sealed using a grommet in order to ensure a watertight seal.
On the right side of the shower, a rectangular protrusion serves a similar purpose.
        This protrusion incorporates another option, the drench hose. Again, the drench hose is
neither standard nor in high demand. A small dimple is built into the mold at the exact places
where the handle and the hose leave the casing. These allow Speakman to drill out precise holes
in the instance where the customer chose to add this option. The heat traced tape needs to be
present on any section of the steel pipe where there is standing water. Along with being heat
traced, it must then be insulated in order to ensure that heat is retained and there is no possibility
of freezing. The rectangular protrusion leaves enough room for heat tracing and insulation to be
present, as well as extra room at the bottom where the hose comes out. The next components to
incorporate were the junction box, scald valve, shower head and ball valve.

             Top Section
         In the top portion of the shower system there are several critical areas, including the
electrical junction box, scald valve, shower head, and the ball valve for turning on and off the
shower. The scald valve is the most difficult of these areas to incorporate into the design of the
top section. For aesthetic and safety purposes, the drain hose from the valve must run through
the inside of the shower shell. This created a problem in the dimension of the shell in this area.
The standard diameter of 3.375 inches would not allow enough clearance for the drain hose to
bend inside of the shell and lay flush along the pipe down to the bottom of the unit without
restricting the flow of water when the valve is in operation. To accommodate for this, we
designed an additional cavity in the top section to enclose more area under the scald valve. This
cavity allows the hose to bend back gently to the pipe frame and run down to the ground for
drainage (see figure 12). This area may also be valuable for mounting the thermostat: the
standard design has changed to a taller unit which, if left mounted in its current location, would
interfere with the shell. Mounting this unit in the new space created by the drain cavity would
avoid further changes in the shell design.




                    Figure 12 – Solidworks drawing of shell near scald valve.



                                                                                                   15
         The shower head, like any other protrusion in the system, requires a grommet at the
transition from shell to pipe, to create a weather tight seal. The head drops down a bit farther
than the diameter of the shell, so we designed a small extension to keep the pipe covered all the
way down to the actual shower head. The extension also has a male lip on its end to accept the
female lip on the grommet. The grommet can even be installed over the shower head itself for a
full weather tight seal.
         To accommodate the additional length of the extension arm, the junction box also needed
to have an extension designed into the shell. This extension is also molded with a male lip to
accept the appropriate grommet. Finally, to accommodate the ball valve for turning the shower
on and off, a hole will simply be drilled in the appropriate location and a push style grommet
fitted into the hole, and anchored using set screws. This grommet will not only prevent water
from entering the hole, but also keep friction on the valve to prevent the shower from
inadvertently turning.


             Insulation
        Currently, the SE-6000 is insulated by closed cell Armacell piping insulation. This
insulation is slit on the manufacturing floor, wrapped around the piping, and then taped tight
around to secure it. Our goal was to significantly improve upon this method thus saving time
and money in reference to the assembly of the insulation onto the shower.
        After examining the problem, we recognized that the simplest, most economical, and
most time efficient insulation choice would be to stay with the closed cell Armacell piping
insulation, but instead use a pre slit, self sealing version rather than a solid piece. After
purchasing a pre slit section, we were able to test its adhesion ability and found it to be
acceptable for use on the shower. By moving to a pre-slit insulation, Speakman should be able
to save money both on the purchase of adhesion tape, which will no longer be necessary, and on
labor costs.


             Sealing Methods
        In order to ensure that the shower meets the weather resistance requirements, we
developed a method for testing and qualifying what the optimum sealing process is. The
modular nature of the shell design has the disadvantage of naturally having many gaps and seams
which potentially could allow water to enter the shell and damage the internal piping and heat
tracing. The aspects that thus needed to be addressed were sealing the seams where the shell
comes together, as well as sealing holes where parts of the shower such as the eyewash bullhorn
and the shower head protrude out of the shower shell.
        The most important sealing aspect that needed to be tested was the seam seals. Since the
shell is required to be removable, a permanent adhesion of the shell pieces (the best sealing
method possible) was not an acceptable design alternative, and we were left to examine the
virtues of internal versus external gasket sealing at the seams. While all of Speakman‟s utilize
similar rubber external gaskets, as a team we observed and decided that this was not the optimal
sealing method because of its unreliable nature. Our decision had been to use an internal gasket
coupled with mechanical fasteners to keep the shell together and sealed water tight.




                                                                                              16
        With an internal gasket chosen, the next step became developing exactly what type of
gasket would be required to ensure that the shower would remain water tight. To do this, we
decided to run a number of tests on actual gaskets that would replicate the extreme conditions
that the shower could potentially be exposed to. To perform these tests, we developed a test
piece that allowed for us to place various gaskets under pressure in between two shell halves.
The shell halves were made of a fiberglass composite piece which allowed for us to replicate the
smooth plastic of our ABS shell at a very low cost without the need for expensive tooling. The
test shell was then mounted on an aluminum frame which allowed for the shell and gasket to be
positioned for testing, as show in Figure 13. The test itself consisted of angling the shell 30
degrees from horizontal, then running water at 4.5 gallons per minute from a ½ diameter pipe
directly onto the gasket at the seam, as show in Figure 14.




                                           Figure 13




                                           Figure 14

        This testing method was developed after examining weatherproofing standards such as
NEMA 250-2003, which details the standard for electrical box enclosures. These standards
actually were in reference to metal junction boxes which house bare electrical connections that
are extremely sensitive to water and dust, and thus did not apply to exactly the same situational
setting that the shower is exposed to; however we felt that they were a good base point to
examine. Our gasket water test was developed by modifying and scaling down the NEMA 250-
2003 watertight tests to a level which we felt was acceptable for what the shower would be
exposed to.
        A total of 6 gaskets were tested, chosen because of their temperature ratings (a minimum
of -20° to 130°F), and because they had self adhesive backs. The temperature rating was an



                                                                                              17
important aspect to include because of the nature of the outdoor decontamination unit, which
must be able to operate in extreme temperatures. The self adhesive backing is required because
of the simplistic nature of assembly in comparison to an extra step of adhesive application within
the assembly process of the shell.
        The results of the testing are shown below in Chart 1:

                                Water Sealant Testing
                               Cost                            Compressed    Water
         Gasket Material    (per foot) Width Initial Thickness Thickness Resistance                Notes
K-Profile EPDM                $0.410   7/32"        0.125"       0.100"   Passed    rated to -40F
P-Profile EPDM                $0.410   7/32"        0.219"       0.080"   Passed    rated to -40F
High Density PVC Foam         $0.074    1/4"        0.188"       0.061"   Passed    rating not noted
Polyurethane Foam Bubber      $0.075    3/4"        0.125"       0.046"   Failed    open and closed cell
EPDM Foam Rubber              $0.288    3/4"        0.125"       0.068"   Passed    rated to -40F
EPDM and Neoprene and SBR     $0.146    3/4"        0.125"       0.074"   Passed    did not recover from compression
                                                         Chart 1

         The highlighted gasket, the 3/4” wide by 1/8” thick EPDM closed cell foam rubber, was
the gasket that we determined would be the best for this application. The rubber‟s temperature
rating is -90° to +257° F, while its adhesive backing is rated from             -40° to +250° F. It
performed perfectly in our water sealing test, lasting 30 minutes (the length of the test) both on
the initial application of the gasket to the shell, as well as two subsequent opening and re-closing
of the test shell.
         We also performed a freeze test on the gasket, in which we wetted the gasket with water,
and then had the test apparatus placed in a freezer at -6°F for 24 hours. Upon the end of this time
period, we subsequently removed the test apparatus from the freezer and opened the shell once
again, and observed no significant damage to the rubber or adhesive. Upon re-closing the shell
and placing it under the water test, it again remained water tight throughout the 30 minute test.
         We chose the gasket to be 3/4” wide in order to allow for our fasteners to be placed
through the middle, ensuring that there will not be any water leaking through the hole for the
fasteners. The 1/8” thickness was chosen in order to ensure that the rubber foam would be thick
enough to allow for compression for sealing, yet not so thick as to detract from the appearance of
the shell itself. At a cost of $0.288 per foot, along with a conservative estimate of 30 feet of
gasket material per shower yields a cost per shower of $8.64.
         The other aspect to the internal gasket seal is the mechanical fastening method that keeps
the gaskets compressed as well as keeps the shell halves together. Making a decision about
which fastener to use was partly determined by the gasket material, and largely by the detailed
design of the shell and how we chose to shape it. Unlike Speakman‟s competitors, we chose to
move away from the vertical flange seen in our test piece because of the dangerous nature of the
flange edge. The competitors benefited from using an external gasket in that it covered the
flange edge and protected it against the potential safety problem of people hitting it. To move
away from the need for an external gasket or some form of edge protection, we chose to turn our
flanges 90 degrees and have them overlap each other, as explained and seen above in the design.
However, this left us with unique problems in fastening the shell.
         With flanges, a number of fasteners could possibly be used, such as nuts and bolts or
plastic barbed push pins. The flanges allowed for the installer to access both ends of the shell
flange, as well as to control the rigidity of both shell sides. However, the design we came up
with prevents any type of user access to the underside of the through hole during assembly, as
well as a limit to the control of the rigidity of the backing shell piece. This means that a nut and



                                                                                                                       18
bolt could not be utilized because there would be no way to tighten it, and a plastic push pin is
out of the question because the rigidity of the underside connection can not be ensured.
        We chose to go with a nylon removable rivet to act as the mechanical fastener (Figure
15). These rivets are designed to be slid into a 0.21” through hole without resistance. The cap is
then pressed down after the rivet is in the hole, which expands out the cut end, locking the shell
between the rivet head and the expanded end. They have a temperature range of -40° to +149° F,
which makes them suitable for the extreme temperatures that the shell will experience. More
importantly, in the tests that we have run, they are capable of applying the necessary pressure to
compress the gasket to ensure water tightness. The rivets cost $0.197 each, at a cost of $9.86 for
50. The rivets are to be placed at a distance of one per foot, which is close enough to overcome
the bowing effects of the gasket seal in between the two rivets, yet far enough apart to be cost
effective. This yields a conservative cost, assuming 30 rivets, of $5.91 for the rivets for one
shower.




                                         Figure 15 - Rivets

        We also needed to take into consideration that both the nylon rivets and the ABS shell
could vary in size due to variations in temperature. Assuming that the operation temperature will
range from -40F to 150F, we calculated the variation based on the linear coefficient of thermal
expansion for both materials. From this, we were able to determine that there would be no
significant change in size of the rivets, but that there would be a change of roughly 0.1” per
every 12” of the ABS shell. To account for this and ensure that the growing and shrinking of the
shell would not put any undue stress on the rivets, we decided to incorporate a 0.4” slot into male
sections of the shell. This allows for the rivets to secure through the 0.21” diameter hole of the
female piece into the slot, but have room for linear shifting of the shell as it shrinks and expands.
        Where piping needs to protrude out of the shell for parts such as the shower head, eye
wash bull horn, and junction box, we needed to take a look at how to prevent water from getting
into the hole. One of Speakman‟s competitor‟s had chosen to use rubber lip sealed plugs to seal
off all holes, into which they then drilled center holes in order to allow for pipes to come
outward (Figure 16). We felt that the lip seal plug was a good idea, because it allowed the hole
to be sealed around the edges, but we felt that just drilling out a hole in the plug does not ensure
a tight enough seal to prevent water from entering. To combat this, we chose to utilize a lip seal
grommet (Figure 17). These grommets come in a number of standard pipe diameters to ensure a
water tight seal around many different pipe sizes. To guarantee that they would be water tight,
we set up a test that pooled water at the grommet area with a pipe running through it, and
checking for leaking (Figure 18). Over the course of 12 hours, we saw a water loss of less than


                                                                                                  19
25%, which we deemed an acceptable loss, especially in comparison to the competition, which
saw 100% loss in less than an hour.




                                         Figure 16




                                         Figure 17




                                         Figure 18

       While we have chosen to use the grommets for most of our pipe seals, for the eye wash
bullhorn (Figure 10 above) we chose not to use a grommet but instead a large rubber washer.


                                                                                         20
   This decision was made because the decontamination shower is normally shipped without the
   bullhorn attached so that there is no danger of it being damaged in shipping. Since the customer
   must then put the bullhorn on, it did not make sense to require them to open the shower shell
   back up so that the bullhorn grommet can be placed in the shell. By using a rubber washer, we
   were able to design the shell so that the bullhorn can be screwed down tight into the shower
   piping, compressing the washer tight to a flat section of the shell, creating a water tight seal.




Prototype
           After finalizing the shell design and testing the sealing components, we moved forward
   with prototyping a full scale ABS shell. The purpose of this prototype was to present a working
   product which could be analyzed for concept flaws when assembled. We turned to the
   thermoformer that we had established with Speakman Company, Maryland Thermoform, to
   produce this prototype. They utilize a special polymer molding process which facilitates
   changing the mold if necessary, making changes possible if necessary.
           The prototype shell provided for a full scale model to ensure that our design ideas and
   preliminary testing was valid. As shown in Figure 19, the shell fit together as expected around
   the pipe frame, in a manner that provides a clean, aesthetically pleasing covering.




                                 Figure 19 – SE-6000 with new shell


                                                                                                 21
Through assembly, we were able to validate that our rivets were capable of securely fastening the
shell together without providing undo trouble during assembly (Figure 20).




                                   Figure 20 - Installing Rivets

We were also able to ensure that the shell fit securely around the piping with the insulation in
place. With the insulation around the piping, the shell provides a rigid and sturdy casing which
will help prevent against impact damage with little flexing. As seen in the cross sectional view
(Figure 21), the shell-insulation-piping system creates an almost uniform thickness.
                                        EPDM Gasket



                                                                   Internal Piping
               ABS Shell




                                                                 Foam Rubber Insulation
       Heat Tracing Tape



                                            3.25”
                                 Figure 21 – Cross section of shell

        Upon reception of the prototype, we were able to examine how the shell assembles and
seals. While we were confident that our shell design would seal based on our previous testing,
the one matter which we could not determine until having a full scale ABS prototype was
whether it could be assembled easily. The issue we were concerned with was whether the gap
for the gasket was going to cause problems with trying to force the two shell pieces together.
What we found upon reception of the prototype shell was that this was not an issue. In fact, we
actually saw just the opposite problem, that in certain areas where the unit curved, the gap was
slightly too great, and there is the potential for leakage. However, this is a problem that is easily
fixed, and options that we are considering include using a thicker gasket material in that area,


                                                                                                  22
putting more rivets in the area to ensure adequate compression, and making the curves a larger
radius to prevent sharp angles from causing issues with pull away.
        The other issues that we found with this initial prototype were dimensional ones. Due to
the nature of the piping structure (which does not have specified dimensions to work off of), we
had issues with two areas that were dimensioned incorrectly. The first place was at the top of the
shower, where the shower head comes out. Our dimensions are about 1 inch shorter than the
shower head location, and thus the shower head protrudes out of the hole off center (seen in
Figure 22). This can and will be addressed during winter session, as two of our team members
continue work on the shower to move Speakman towards the production of the new shell. The
other issue with dimensioning came from the location of a hole that allows the rivets to pass
through where the bottom and middle sections meet. The holes do not line up perfectly, and
without this hole the rivets are unable to pass through and connect. However, this is a tooling
issue, and is very easy to correct, and thus is not a big problem.




                           Figure 22 – Misalignment of shower-head

        We also had an issue with wall thinning, which we were hesitantly expecting. At the
location of the paddle handle for the optional drench hose, we needed to design a box that comes
out of the side of the shell. This box caused the vacuum-forming process to stretch the ABS
extremely thin, reducing the structural strength in this area to unacceptable levels (shown in
Figure 23). We are working on devising a method of fixing this problem, ranging from tapering
the box to creating a detachable case.



                                                                                               23
                                                             Wall
                                                             Thinning




                                     Figure 23 – Wall Thinning

          All of these issues, however, are minor and can be fixed through slight variations of
   design. As a whole, the prototype shower came out as expected, fitting together as dimensioned,
   providing what we feel is a clean, aesthetically pleasing look.


Cost Analysis
         The shower design work and testing has yielded many benefits over Speakman
   Company‟s current shower design, and also trumps the showers currently produced by
   Speakman‟s competitors. As shown in Chart 2, we have estimated to have cut over $150 per unit
   from Speakman‟s current shower shell design, reducing the cost from over $390 to an estimated
   $225.




                                                                                               24
       Unit Cost $/Unit
       400 units/year, 10 years
                                  Current Speakman Model Competitor   New Concept Design

       Material                           319.97            90               60.05
       Production price                     0               120               119
       Contracted Molding                   0                3                2.19
       Assembly Cost                      71.81             70                 45

       Total                              391.78            283             226.24
                                               Chart 2

         The cost shown in Chart 2 is derived from a cost analysis of the sealing and fastening
materials, material cost for the ABS plastic sheets, and a quote from Maryland Thermoform.
The cost of prototyping and non-recurring engineering costs (cost of making the mold) was
spread out over a time period of ten years, assuming 400 units produced per year. The assembly
cost is an estimate comparing the assembly time of the current unit and how long it took two of
our team members to assemble our prototype shell. This part of the cost might have some room
for error, because our concept has a different assembly method than their current one. For the
current model of the SE-6000, the assembly steps for the steel piping frame of the shower, the
heat tracing tape, the insulation, and the shell are simultaneous – that is, one section of the
shower is completely assembled (frame, insulation, shell) and then attached to the next section
that has been assembled. Our concept allows the assembly workers to put together the piping,
heat tracing tape, and insulation for the whole shower first, and then put on the shell on the
shower as a whole. However, we think the $30 cost reduction in assembly is a reasonable
estimate based on the time it took to assemble the shell, and how long it took Speakman to
assemble to shower for us.
         The cost reduction seen in material (as compared to the current SE-6000 and the
competition) is due to the economic sealing and fastening methods we have designed and
justified. The use of removable nylon rivets, at $0.20 each, EPDM foam rubber gasket material,
at $0.29/ft, and lip style rubber grommets, at approximately $1 each, enable the shell to be
effectively sealed and held together for the least amount of money (See appendix F for a parts
list for sealing, fastening, and insulation components).
         The decrease in manufacturing cost of the exterior shell is a subsection of the SE-6000‟s
total unit cost. As the exterior shell is the only subsection to be changed in our modification of
the shower system, the reduction in manufacturing cost will cause the only change seen in the
unit cost. Because the outdoor safety shower market is consistent, our modification of the shell
design will not cause a significant variation in the number of products sold; thus our goal is to
reduce cost to Speakman. If Speakman maintains the same unit price to consumers, the
reduction seen in unit cost will raise the net present value of the product (See Appendix C). As
the NPV charts show, moving forward with our concept will result in an NPV of approximately
$2.86 million over a period of five years. This shows an improvement of $150,000 over that
time period when compared to their current product. In addition to this cost advantage,
Speakman will have the benefits of a shower that is innovative and competitive in the market
place, which will result in more units being sold per year. This increase in units sold was also
not accounted for in our NPV comparison (Note that the use of the NPV spreadsheet was not



                                                                                               25
   meant as an assessment of Speakman‟s business plan, but rather a justification for moving
   forward with our concept design).
          Based on this cost analysis, we have shown that we‟ve created a design that is better
   functionally than the competition, and also shows a reduction in cost when compared to the
   current SE-6000 and competitor‟s products. This design will save Speakman a considerable
   amount of money and allow them to stay competitive within the marketplace.


Path Forward
           With rapid prototypes and a full scale prototype to validate our concept, part of our team
   will work towards the finalization of this product. Over the course of the Winter session and
   beginning of the Spring session, Colby and Joey will work to complete the design phase, further
   validate the design by performing system level tests and transition the product from prototype to
   production. This will be accomplished through the completion of Speakman‟s expectations as
   follow.
           The team will begin by finalizing anything left incomplete from the fall project. This
   could include making minor adjustments to our engineering drawings, such as dimensioning and
   tolerancing issues, or a finalized cost listing that may incorporate expenses that arise after the
   semester has ended. Once any „loose ends‟ from the fall project are taken care of, the team will
   begin testing the prototype. The first stage of testing will be simply to assemble a finalized unit.
   This will ensure that all pieces fit together, can be easily assembled and just as easily taken apart.
   If this does not prove true, then the necessary modifications will be made to the prototype in
   order to make the pieces fit together perfectly. Upon completion of this task, we will shift our
   concentration to the accessories.
           We will begin by validating that all possible options can and will fit into the shell design.
   This will be validated by physically making the necessary cutouts and installing all possible
   options to the unit. Once any adjustments to the design are made and the unit incorporates all
   possible options, the unit will be put through extensive weather testing. The SE-6000 will be
   tested in climates ranging from tropical to arctic through the use of a testing facility to which
   Speakman currently has access. This test will validate the sealing and fastening method and the
   durability of ABS plastic. Again, any necessary changes will be made if a problem is
   encountered. Upon complete validation of the design, we will begin both manufacturing and
   user manuals.
           The first set of instructions developed will be for assembly purposes. They will first
   discuss any fixtures or extra tooling necessary to prepare the unit for assembly. An example of
   the extra tooling include applying the gasket to one side of the shell, and puncturing holes in the
   gasket in order to make insertion of the fasteners easier. Next, they will explicitly state the order
   that the pieces go on, where they are to be inserted, how to put them on and how to correctly
   insert the fasteners. With close attention to detail, this manual will enable any factory worker to
   assemble all of the components of the SE-6000 to a finalized base unit. Further instructions will
   then be developed in order to incorporate all optional accessories. These instructions will be
   designed to minimize time and effort, while maximizing production efficiency.
           For use in the field, another set of instructions will exist. These instructions will utilize
   engineering drawings to make the addition of an option by a secondary party as simple as
   possible. It will also include additional maintenance requirements for the shell, as well as any


                                                                                                      26
existing requirements that Speakman has for the SE-6000. Once the design has been validated
through testing, all accessories are accounted for and the various necessary instruction manuals
are finalized, the only things left to focus on are the packaging and the final business framework.
        With the assistance of Speakman, we intend to work with their existing packaging
company to discuss the specifics of our new design‟s packaging. We are not yet sure what that
encompasses, as the new design could possibly fit fine in the existing packaging, or a new one
may need to be designed altogether. This is a subject that will be further investigated and
finalized. Once the packaging is finalized, the last subject of interest before production is the
business framework. This framework will include a listing, as well as a cost, of all necessary
parts for the shell and the base unit, a finalized labor cost after assembly time is accurately
established and a comparison to the former design.
        The finalized comparison plays a key role in the end of this project, as our original goal
was to design an innovative product that effectively cut down costs. As previously stated, we
predict that there will be significant savings, but this final comparison will validate that. We
believe that the path forward listed is feasible in the timeframe that we have to work with, and
that the new and improved SE-6000 Outdoor Safety Shower will be in production in 2006.




                                                                                                27
Appendix A:
       UDesign Spreadsheets




                              28
Ordered
Metrics                    %
Cost                       14.32
Water tightness            12.16
UV resistant               11.59
Temperature range          11.51
Assembly time              11.47
Thermal conductivity       10.59
Number of options           7.73
Number of pieces            7.58
Volume                      3.59
Weight                     3.25
Color                       2.40
Number of reusable parts    1.70
Elastic modulus            1.21
Number of sharp corners     0.89




                                   29
           Mission
          Statement:             To design an outer shell for the SE 6000 that meets all of the customers wants and needs.
           Concepts              Concept Descriptions
           Benchmark             Vacuum formed shell with clamshell seal with lip covered by external gasket from Bradley, Haws, Econ
               A                 vacuum formed shell with lip and internal gasket and fasteners
               B                 vacuum formed shell where edges of shell overlap, sealed with internal gasket and fasteners
               C                 Modified PVC shell
               D
               E
               F
               G
               H
               I
                                             Concept Selection Table
                              Metric Information                                                   Conceptual Solutions
                                                            Benchmark       A          B          C        D           E           F    G   H
Metrics                               %      Target value
            Cost                    14.32          $250        0.2          1          1          -1
       Water tightness              12.16          1.0         0.2          1          1          1
         UV resistant               11.59          1.0         0.2         0.2        0.2        0.2
      Temperature range             11.51    -50 to 150 F      0.2         0.2        0.2        0.2
       Assembly time                11.47      15 min          0.2         0.2         1         -1
     Thermal conductivity           10.59     = current        0.2         0.2         1         0.2
      Number of options              7.73          5.0         0.2         0.2        0.2         -1
      Number of pieces               7.58        6.0           0.2          1          1         -1
            Volume                   3.59     = current        0.2         0.2        0.2        0.2
          Weight                    3.25      = current        0.2         0.2        0.2         -1
            Color                    2.40     = current        0.2         0.2        0.2        0.2
   Number of reusable parts          1.70     = current        0.2         0.2        0.2         -1
      Elastic modulus               1.21      = current        0.2         0.2        0.2          1
   Number of sharp corners           0.89           0          0.2         0.2         1         0.2


Better than benchmark                                                       3          6          2
Worse than benchmark                                                        0          0          6
Same as benchmark                                              14           11         5          6
Unknown relationship                         Sum-Up
              Score                                           20.00       47.25      65.61      -24.57

Compared to benchmark:                         Symbol         Value
Better than benchmark                            b               1      Perform this check in a round robin fashion.
Worse than benchmark                             w              -1      Let the prevailing concept from one round be
Same as benchmark                                s             0.2      the benchmark in the next!
Unknown relationship                             u             "0"




                                                                                                                                                30
                                                    Concept Iteration Template
        Current Rank          Concept ID.             Concept Description
              1               Best                    vacuum formed shell where edges of shell overlap, sealed with internal gasket and fasteners
              2               A                       vacuum formed shell with lip and internal gasket and fasteners
              3               B                       Vacuum formed shell with clamshell seal with lip covered by external gasket from Bradley, Haws, Econ
              4               C                       Modified PVC shell
              5               D
              6               E
              7               F
              8               G
              9               H
              10              I
                                        Concept Selection Table
                                  ID.      Best    A           B         C             D          E           F       G         H           I
           Metrics                 %                           Vacuum of shell overlap, clamshell and with gasket and
                                        vacuum formed shell formededges with lipshell internal gasket seal fasteners 0 by external gasket0from Bradley, Haws, Econ
                                                                         Modified PVC sealed                0                 0
                                                   vacuum where shellformed and withshell 0 with internal lip covered fasteners                     0
            Cost                14.32        0.2         0.2         -1.0       -1.0
       Water tightness          12.16        0.2         0.2         -1.0       0.2
         UV resistant           11.59        0.2         0.2         0.2        0.2
      Temperature range         11.51        0.2         0.2         0.2        0.2
       Assembly time            11.47        0.2         -1.0        -1.0       -1.0
     Thermal conductivity       10.59        0.2         -1.0        -1.0       -1.0
      Number of options          7.73        0.2         0.2         0.2        -1.0
      Number of pieces           7.58        0.2         0.2         -1.0       -1.0
            Volume               3.59        0.2         0.2         0.2        0.2
          Weight                3.25         0.2         0.2         0.2        -1.0
            Color               2.40         0.2         0.2         0.2        0.2
   Number of reusable parts     1.70         0.2         0.2         0.2        -1.0
      Elastic modulus           1.21         0.2         0.2         0.2        1.0
   Number of sharp corners      0.89         0.2         -1.0        -1.0       -1.0

Better than benchmark
Worse than benchmark
Same as benchmark
Unknown relationship
              Score                         20.00       -7.54      -48.41      -48.07




                                                                                                                                                31
Appendix B:
            Manufacturing Costs




    Unit Cost $/Unit
    400 units/year, 10 years
                               Current Speakman Model Competitor   New Concept Design

    Material                           319.97            90              60.05
    Production price                     0               120              119
    Contracted Molding                   0                3               2.19
    Assembly Cost                      71.81             70                45

    Total                              391.78            283             226.24




                                                                                        32
                                                                                                                                                                                           33
                                                                                                                               NPV based on our modifications to the SE-6000 outer shell
                                                                    2005       2006     2007       2008     2009     2010
                                   VALUE SYNTHESIS
                                                           YEAR>     0           1        2          3        4        5
                                     UNIT SALES             #                     400      400        400      400       400
                                $ In UNIT PRICE             $                   3700     3700       3700     3700      3700
                                     REVENUE               $m                   1480     1480       1480     1480      1480
                                     MARGIN                %                       81       81         81       81        81
                                     OPN COSTS             $m                     281      281        281      281       281
                                     UNIT COST              $                     703      703        703      703       703
                               $ Out DES/DEV COST          $m          8.75         3
                                     CAP COST              $m                       0
                                     TOT COST              $m              9      284       281      281      281       281
                                     DEPR OF CAP 10%/yr)   $m                       0         0        0        0         0
                                     BT EARNINGS           $m            -9     1196       1199     1199     1199      1199
                                     AT EARNINGS           $m            -5       717       719      719      719       719
                               Value DISCOUNTED EARNINGS   $m            -5       664       617      571      529       490
                                    NPV                    $mm       2.86
                                    Discount Factor*                 1.000     0.926       0.857   0.794    0.735     0.681
              NPV comparison




                                    Cost of Capital        0.08
                                                  yr
                                     * 1/(1+CoC)                   Input
                                                                   Calculated from input
Appendix C:

                                                                   Given
                                                                                                                                                      34
                                     2005       2006     2007       2008     2009     2010




                                                                                               NPV based on Speakman’s current model of the SE-6000
    VALUE SYNTHESIS
                            YEAR>      0         1        2           3        4        5
      UNIT SALES              #                   400      400         400      400      400
 $ In UNIT PRICE              $                  3700     3700       3700     3700     3700
      REVENUE                $m                  1480     1480       1480     1480     1480
      MARGIN                 %                     76       76          76       76       76
      OPN COSTS              $m                   350      350         350      350      350
      UNIT COST               $                   875      875         875      875      875
$ Out DES/DEV COST           $m             0        0
      CAP COST               $m                      0
      TOT COST               $m             0     350        350      350      350      350
      DEPR OF CAP 10%/yr)    $m                      0         0        0        0        0
      BT EARNINGS            $m             0    1130       1130     1130     1130     1130
      AT EARNINGS            $m             0     678        678      678      678      678
Value DISCOUNTED EARNINGS    $m             0     628        581      538      498      461
     NPV                    $mm       2.71
     Discount Factor*                 1.000     0.926       0.857   0.794    0.735    0.681
     Cost of Capital        0.08
      * 1/(1+CoC)yr                 Input
                                    Calculated from input
                                    Given
Appendix D:
       Material properties comparison




                                        35
Appendix E:
       Competition Specs




                           36
37
Appendix F:
                 Parts List
                                       Parts list for outer shell of SE-6000

Part #        Description                                            Source      Bulk Unit Cost Cost per piece # per shower Cost per shower
          Nylon reusable snap-
          lock rivet 0.201'' -
          0.205'' hole diameter,                                                 $9.53 for pack
91020A350                                                             McMaster                        $0.19        38           $7.24
          0.295''-0.335'' material                                                   of 50
          thickness, 0.472'' head
          diameter, 0.37'' long

           Adhesive-backed
           EPDM foam rubber                                                       $14.38 for 50
 93725K56                                                             McMaster                      $0.2876/ft    ~35 ft        $10.07
           strip, 1/8'' thick, 3/4''                                                  feet
           wide, 50' long
           Slit elastomer foam
           rubber pipe insulation
 44745K29                                                             McMaster   $9.53 for 6 feet    $1.59/ft     ~9 ft         $14.30
           1/2'' thick, 1-3/8''
           insulation ID, 6' long
           Slit elastomer foam
           pipe fitting insulation
93715K87 *                                                            McMaster        $4.86           $4.86         3           $14.58
           tee, 1/2'' thick, 1-3/8''
           insulation ID
              Lip style PVC sealing
              grommet for pipe and
              tube for 1-1/4'' pipe, fits Grommet for shower
 63595K37                                                             McMaster   $10.90 for ten       $1.09         1           $1.09
              1.625'' to 1.750'' pipe     head
              diameter, 1.520 ID,
              3.125'' OD, 0.635 thick

              Lip style PVC sealing
              grommet for pipe and
              tube for 3/4'' pipe, fits Grommet for junction
 63595K35                                                             McMaster    $7.30 for ten       $0.73         1           $0.73
              1.020'' to 1.109'' pipe   box
              diameter, 0.970 ID,
              2.437'' OD, 0.580'' thick

              Lip style PVC sealing
              grommet for pipe and
              tube for 1'' pipe, fits   Grommet for
 63595K36                                                             McMaster   $10.60 for ten     $1.06 each      1           $1.06
              1.300'' to 1.399'' pipe   temperature gauge
              diameter, 1.235'' ID,
              2.875'' OD, 0.610'' thick

              Lip style PVC sealing
              grommet for pipe and
              tube for 1/2'' pipe, fits Grommets for ball valve
 63595K34                                                             McMaster    $6.10 for ten     $0.61 each      2           $1.22
              0.825'' to 0.919'' pipe   paddle handles
              diameter, 0.775'' ID,
              2.000'' OD, 0.546'' thick

              Plug style PVC sealing
              grommet for pipe/tube
              for 3/4'' pipe, fits 0.820'' Grommets for ball valve
  920k33                                                              McMaster    $22.30 for 10     $2.23 each      1           $2.23
              pipe diameter, fits          pull handle for shower
              1.310'' hole, 0.820'' ID,
              2.000'' OD, 0.729'' thick


* tees are not necessary - only use if
       they can be found at an
     economically feasible price.




                                                                                                                                              38
Appendix G:
       2-d Dimensioned Solidworks Drawings of Shell




                                                      39
40
41
42
43
44
Appendix H:
              Thermal Expansion Equations

                      m
 nylon  8.1E  5
                     m C
                                          Temperature Range: -40C to 65.5C
                       m
 ABS     11.0 E  6
                      m C

Nylon Length: 0.295 inches = 0.007493 m
ABS Length: 12 inches = 0.3048 m

Expansion: R final   * Linitial * T

Nylon:                                    ABS:
R final   * Linitial * T                R final   * Linitial * T
R final  8.1E  5 * 0.007493 * 105 .5      R final  11 .0 E  5 * 0.3048 * 105 .5
R final  0.000064 m  0.0025 inches        R final  0.00354 m  0.1394 inches




                                                                                      45

				
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