Document 525 PRE-IMPLEMENTATION REPORT CHAPTER: …
Transcript of Document 525 PRE-IMPLEMENTATION REPORT CHAPTER: …
Document 525
PRE-IMPLEMENTATION REPORT
CHAPTER: University of Minnesota
COUNTRY: Guatemala
COMMUNITY: Agua Caliente
PROJECT: Expanding Agricultural Opportunities
Prepared By
Nick Bodette
Rebecca Herron
Kim Haglund
Jacob French
Jacob Robole
Lucas Green
Isaac Murphy
Isaac Johnson
Anirudh Srivatsa
Alex Motley
Burke Minahan
12-15-2013
ENGINEERS WITHOUT BORDERS-USA
www.ewb-usa.org
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 2 of 58
Table of Contents Pre-Implementation Report Part 1 – Administrative Information .................................................. 4
1. Contact Information ............................................................................................................. 4 2. Travel History ...................................................................................................................... 5 3. Travel Team ......................................................................................................................... 6
4. Health and Safety ................................................................................................................. 6 5. Budget .................................................................................................................................. 7 6. Project Discipline ................................................................................................................. 9 7. Project Location ................................................................................................................... 9 8. Project Impact .................................................................................................................... 10
9. Professional Mentor Resume ............................................................................................. 10 Pre-Implementation Report Part 2 – Technical Information ........................................................ 12
1. Executive Summary ........................................................................................................... 12 2. Introduction ........................................................................................................................ 13 3. Program Background ......................................................................................................... 14
3.1 Project Partners ............................................................................................................... 14
3.2 Community Description .................................................................................................. 15 3.3 Community Priorities ...................................................................................................... 15
3.4 Water Sources ................................................................................................................. 16 3.5 Community Relations ..................................................................................................... 16
4. Facility Design ................................................................................................................... 17
4.1 Description of the Proposed Facilities ............................................................................ 17 4.2 Experiment Design Background ..................................................................................... 18
4.3 Design of Experiment ..................................................................................................... 18 4.4 Experimental Methods .................................................................................................... 19
4.5 Results and Discussion ................................................................................................... 20 4.5.1 VALVE #1 ................................................................................................................... 21 4.5.2 VALVE #2 ................................................................................................................... 22
4.5.3 VALVE #3 ................................................................................................................... 23
4.6 Drawings ......................................................................................................................... 25 4.7 Names and Qualifications of Designers .......................................................................... 25 4.8 524 - Draft Final Design Report Comments ................................................................... 25
5. Construction Plan ............................................................................................................... 26 6. Materials List and Cost Estimate ....................................................................................... 28
7. Sustainability...................................................................................................................... 28
7.1 Background ..................................................................................................................... 29
7.2 Operation and Maintenance ............................................................................................ 29 7.3 Education ........................................................................................................................ 30 7.3.1 Workshops and Community Interaction ...................................................................... 30 7.3.2 Introducing New Farmers to the System ..................................................................... 30 7.3.3 Measuring the Increased Output of Existing Pumps.................................................... 30
7.3.4 Introducing New Delivery Height to Community ....................................................... 31 8. Signed Implementation Agreement ................................................................................... 31 9. Site Assessment Activities ................................................................................................. 33
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
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10. Professional Mentor Assessment ................................................................................... 33 10.1 Professional Mentor Name and Role ............................................................................ 33
10.2 Professional Mentor Assessment .................................................................................. 33 10.3 Professional Mentor Affirmation .................................................................................. 34
Appendix A – Existing System Pictures ................................................................................... 35 A.1 Check Valve ................................................................................................................... 35 A.2 Waste Valve ................................................................................................................... 35
A.3 Air Chamber ................................................................................................................... 38 A.4 Exemplary Existing Pumps ............................................................................................ 39
Appendix B – Lab Testing ........................................................................................................ 42 Appendix C – Analysis of Experimental Design ...................................................................... 48
Appendix D – Cited Sources..................................................................................................... 58
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
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Pre-Implementation Report Part 1 – Administrative
Information
1. Contact Information
Name Email Phone Chapter
Project Lead Jacob French [email protected] (314) 629-5100 UMN
Project Lead Rebecca Herron [email protected] (319) 431-5517 UMN
Ram Pump Lead Nick Bodette [email protected] (651) 295-7032 UMN
President Kelly Stifter [email protected] (651) 328-1937 UMN
Mentor #1 Kevin Miller [email protected]
om
(612) 644-1170 MN
Mentor #2
(Travelling)
Kim Haglund kim.haglund@gmail.
com
(651) 308-8147 MN
Mentor #3
(Travelling)
Justin Schnee [email protected]
m
(651) 230-4199 MN
Faculty Advisor Matt Simcik [email protected] (612) 626-6269 UMN
Health and Safety
Officer
Brian Anderson [email protected] (507) 696-3452 UMN
Health and Safety
Officer
Rachel
Orlovsky
[email protected] (262) 498-8413 UMN
Assistant Health
and Safety
Officer
Alex Motley [email protected] (314) 704-9058 UMN
NGO/Community
Contact
Elizabeth
Howland
om
01150249328889 Long
Way
Home
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 5 of 58
2. Travel History
Dates of
Travel
Assessment or
Implementation
Description of Trip
August
10-23
2011
Assessment Met with representatives from the APROMAC within the
community. Discussed the existing design and use of current
Irrigation Dams and ram pumps, as well as their future goals for
the system. Introduced them to EWB mission and process and
confirmed their desire to form a partnership. Additionally,
performed preliminary analysis of the Irrigation Dam integrity
and surrounding soil quality.
March
10-19
2012
Assessment Met again with the APROMAC and established the foundation
for further assessment with objectives to strengthen water
distribution and storage infrastructure as determined feasible.
The focus of interaction was strictly to discuss possibilities.
Irrigation Dam measurements and benchmarks were taken for
each of five Irrigation Dams. GPS readings were taken over
various locations to create geographical survey of the land.
Community surveys were conducted from members of the
Irrigation Dam association and community members who were as
of yet unaffiliated.
August
17 – 27
2012
Assessment Met again with the APROMAC and signed an MOU for second
assessment. Data collection from the March 2012 assessment was
continued with GPS surveys, land surveys, community surveys,
water testing, soil testing, and hydrologic measurements. Much
work was done on the land surrounding the third Dam due to the
possibility of collapse of the Dam.
August
8-30
2013
Implementation EWB-UMN implemented a dam reinforcement to Dam 3 in Agua
Caliente. Despite minor setbacks, the team managed to work hard
to get most of the concrete poured and left careful instructions for
some hired workers and our NGO coordinator from Long Way
Home to finish the project. The project was entirely completed
approximately 2 months after our departure, and everything was
completed to EWB-UMN’s standards and specifications. We
consider this implementation a success.
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
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3. Travel Team # Name E-mail Phone Chapter Student or
Professional
1 Jacob French [email protected] (314) 629-5100 UMN Student
2 Rebecca Herron [email protected] (319) 431-5517 UMN Student
3 Nick Bodette [email protected] (651) 295-7032 UMN Student
4 Kim Haglund [email protected] (651) 308-8147 MN Professional
5 Jacob Robole [email protected] (612) 229-9205 UMN Student
6 Samantha Meyer [email protected] (763) 607-6920 UMN Student
7 Burke Minahan [email protected] (920) 495-8726 UMN Student
8 Daniel Hoffman [email protected] (715) 803-5666 UMN Student
9 Justin Schnee [email protected] (651) 230-4199 MN Professional
4. Health and Safety The health and safety requirements have already been evaluated and collected in the Health and
Safety Plan. The travel team will refer to this document for any and all safety concerns. Among
other things, this document includes safety procedures and guidelines for in-country security,
worksite safety, and biological/chemical safety.
Security of the travel team is a significant concern. While petty crime has been rated at medium
to high by International SOS, team members can minimize danger by travelling in groups, as
well as always carrying cell phones. Team members should also inform others of where they
plan to go, and an estimated time of return. Finally, danger can be minimized by exercising
reasonable caution.
Main concerns for worksite safety are centered on personal safety. In order to ensure the
wellbeing of any workers on site, personal protection is mandatory. Steel toe work boots and
hefty pants should be worn by any on-site personnel. Gloves must be worn when working with
power tools. Waterproof rain boots should also be worn for any work in the streambed.
The only chemicals the travel team will encounter are chlorine and the metal lubricant,
Molybdenum. To minimize problems, chemical resistant gloves should be worn when
encountering these chemicals. The environment does pose significant biological hazards as well.
In order to minimize risk of disease, the group should avoid drinking the water, and only drink
bottled water from trusted vendors. Team members should also be aware of venomous snakes,
spiders and scorpions. To minimize risk, team members must be aware of their surroundings, as
well as educate themselves on first aid techniques.
Planning, Monitoring, Evaluation and Learning
The travel team has reviewed the 901B – Program Impact Monitoring Report template and
has assigned travel team members to complete this report during the upcoming trip. We
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University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 7 of 58
acknowledge that the completed 901B is required with the eventual submittal of the 526 –
Post-Implementation Trip Report. ___Yes ___No
5. Budget Project ID: University of Minnesota Agua Caliente, Guatemala
Type of Trip: Implementation = $3,700
Item Quantity
Unit
Price
Total
Cost
Travel
Airfare 9 round trip flights $850 $7,650
Gas Q1000 to LWH for 1 week $130 $130
Transportation 2 Trips to the airport $80 $160
Misc. To LWH $500 $500
Total $8,440
Travel Logistics
Inoculations Inoculations for 9 people $10 $90
Insurance 9 people $15.75 $142
Total $232
Food and Lodging
Lodging
9 people for 9 nights, 81 man
nights $10 $810
Food and Beverage Dinner @ Feliciano’s 81 times $3.75 $304
Misc. Gratuity $20 $20
Total $1,134
Labor
In-country Logistical
Support
Internet access at LWH for 1
week $25 $25
Local Skilled Labor Half days work for welding $200 $100
Misc. Translator for the week $1,000 $1,000
Total $1,125
EWB-USA
Program QA/QC Implementation $3,700 $3,700
Total $3,700
Materials
4in Flange 20 $12 $240
4in Elbow 5 $15 $75
4in Pipe 3ft $5 $15
Bolt 85 $0.80 $68
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 8 of 58
Washer 160 $0.33 $53
Nut 100 $0.40 $40
Rubber Gasket 10 $5 $50
Threaded Rod 7 ft. $1.50 $11
Extra Rubber 2ft^2 $5 $10
Metal Bushing 5 $1 $5
Metal Weights 30 $1 $30
Total $596
Grand Total $15,227
EWB-USA Headquarters use:
Indirect Costs
EWB-USA
Program Infrastructure (2) See Below $0
Sub-Total $0
TRIP GRAND TOTAL (Does not include Non-Budget Items)
$0
Program Infrastructure (EWB-USA Headquarters accounting, administration and
fundraising)
Assessment = $500
Implementation = $1,200
Monitoring = $350
Non-Budget Items:
Additional Contributions to Project Costs
Community
Labor 2 Laborers for Ram Pump Construction
Materials All materials required to assemble and
improve valves and pumps
Logistics None
Cash None
Other Community members to attend ram pump
workshops
Community Sub-Total
EWB-USA Professional Service In-Kind
Professional Service Hours 144
Hours converted to $ (1 hour = $100) $14,400
Professional Service In-Kind Sub-Total $14,400
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
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TRIP GRAND TOTAL (Includes Non-Budget
Items) $0
Chapter Revenue
Funds Raised for Project by Source
Actual Raised
to Date
Source and Amount (Expand as Needed)
Engineering Societies $1000
Corporations $0
University $3000
Rotary $0
Grants - Government $0
Grants - Foundation/Trusts $4000(project)
Grants - EWB-USA program $0
Other Nonprofits $0
Individuals $2400
Special Events $247.26
YEC $4000(project)
Misc. $0
EWB-USA Program QA/QC Subsidy (3) See below $ 0
Total $13,647.26
Remaining Funds Needed $1579.74
Program QA/QC & Infrastructure Subsidy:
Assessment = $1450
Implementation = $3,800
Monitoring = $950
6. Project Discipline Water Pumps and distribution.
7. Project Location
Agua Caliente Community Center:
Longitude: 14°48’18.76” Latitude: 90°51’71.23”
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 10 of 58
8. Project Impact Number of persons directly affected: 150
Number of persons indirectly affected: 400
9. Professional Mentor Resume Kim Haglund
Education:
University of Minnesota, Twin Cities
Bachelor of Biomedical Engineering, 2007
Minor: Spanish Studies
Experience:
R&D Engineer
Vision-Ease Lens, Ramsey, MN
February 2008 – Present
- Responsible for development, improvement, and coordination of tests on ophthalmic
lenses and raw materials
- Oversee mechanical, analytical, optical, performance, and reliability testing on such
technologies as injection molding, cast molding, dip coating, vacuum coating,
photochromic dyes, and polarized film
- Work closely with Quality organizations in the U.S., Thailand, and Indonesia to ensure
consistency in test methods and results
- Supervise a team of one scientist and four technicians
- Manage the safety and organization of all research laboratories
R&D Engineer, Sustaining Engineering
Boston Scientific Corporation, Maple Grove, MN
June 2007 – November 2007
- Supported commercialized products in stents and coatings
- Collaborated on various projects with Operations, Quality, Marketing, and Regulatory
Affairs
Research Assistant, Department of Chemical Engineering and Materials Science
University of Minnesota, Minneapolis, MN
February 2004 – May 2007
- Conducted research on fuel cells, including ink-jet and laser-printed electrodes
- Performed electrode position testing of Platinum and Platinum/Ruthenium anodic films
- Managed and maintained the “Dry Room”, a low-humidity laboratory
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
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R&D Intern
Boston Scientific Corporation, Maple Grove, MN
May 2006 – August 2006
- Conducted extensive literature research on PLGA-based coating for drug-eluting stent
- Prepared and tested polymer samples for dry and wet adhesive strength
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Expanding Agricultural Opportunities
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Pre-Implementation Report Part 2 – Technical Information
1. Executive Summary Expanding Agricultural Opportunities is a mechanical project proposed by the University of
Minnesota Engineers Without Borders Chapter (EWB-USA UMN). An implementation is
planned, during which EWB-UMN will hold several workshops with the community, explaining
the improved design and maintenance requirements for a series of existing hydraulic rams.
EWB-USA UMN has carried out extensive testing on a full scale model of the ram pumps found
in Agua Caliente with EWB-USA UMN designed valves, as well as a replica of a valve found in
Agua Caliente. EWB-USA UMN is requesting TAC approval for the experimental methods,
design, and results of the chapters ram pump study in order to share the results with the
community.
The overall goal of this project is to improve APROMAC’s entire agricultural water distribution
system in Agua Caliente. EWB-UMN recently completed a project to reinforce the biggest and
most exposed of the five dams in the Agua Caliente system, dam 3. The remaining dams were
either structurally sound, or not feasible to repair due to location or inherent design flaws. After
the integrity of the system was secured, the logical next step in the project was to improve the
efficiency and power of the ram pumps, thus improving the usefulness of the system to the
community, while potentially allowing more people to participate in the APROMAC co-op
because of the increased capability and range of the rams.
Our NGO, Long Way Home, has a long standing relationship with Agua Caliente, and has
helped us with communication with the community. Agua Caliente is a small farming
community in central Guatemala, which is home to APROMAC, an agricultural co-op focused
on blackberry production, which owns the agricultural water distribution system. APROMAC’s
system was originally designed by the community of Agua Caliente, which consists of a series of
five dams that vary in size, design, and structural stability. Installed on each of the dams are
several ram pumps that pump water up to agricultural fields at elevations above the stream. This
allows the community to grow crops in the dry season, increasing their yield and profit. This
allows their children to go to school longer improves the nutrition of the town, and improves the
economy of the community and surrounding area because the farmers with ram pumps hire
outside workers to tend their fields in the dry season. The community reached out to our group in
order to reinforce and improve the system, which is quickly falling apart because of lack of
knowledge and experience. The dams were replicated based on a local Guatemalan engineer’s
design, and the rams were developed by the community based on an encyclopedia entry on
Persian pumps. Because everything was originally built by the community, we know they have
invested significantly in the system already. EWB-USA UMN has drafted a Memorandum of
Understanding (MOU) between EWB-UMN and APROMAC, which can be found in section 9
of this document, and is currently working with Long Way Home and the community to get the
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 13 of 58
document signed. We keep in contact with the community via the proposed monthly calls
facilitated through Long Way Home.
In August 2013 EWB-UMN successfully completed an implementation to reinforce dam 3 on the
Agua Caliente system. Two assessment trips were taken prior to the dam implementation.
Additionally, EWB-UMN has been very active in the greater Agua Caliente area, including the
construction of a large scale rainwater harvesting system in the nearby community of
Simajahuleu. All of these previous trips have been in conjunction with Long Way Home.
Due to the complex mechanics and lack of accurate mathematical models of ram pumps, our
chapter opted to make a model ram pump to test under various stroke lengths and valve weights.
Minitab was used to analyze the experimental results. This full analysis can found under section
5.3.
Creo was used to make a 3D model of the ram pumps found in Agua Caliente, based on detailed
measurements taken during previous assessments and the last implementation. The complete
drawing set can be found in the PDF attached with this document.
Due to the heavy design emphasis of this project, it was decided that the best way to disseminate
the new design information was through a series of workshops with the community, during
which new valves will be built and assembled with an existing ram body with members of
APROMAC. This process will give the each member of APROMAC access to the new design
and allow them to make improvements on their individual pump as they see fit. This will also
allow prospective new members to see how to design the pumps and use them if they decide to
join the system.
2. Introduction Since August 2011, EWB-USA UMN has been working in the community of Agua Caliente to
improve a deteriorating agricultural water system, which has been functioning since 1990. The
system is operated by a local farming cooperative called APROMAC and consists of 42 ram
pumps and five dams, as well as a handful of fields which contain water storage tanks and micro-
irrigation pipes. EWB-USA UMN has been working closely with APROMAC and our NGO,
Long Way Home, to determine the best way to improve the system. In March and August 2012
it was determined that Dam 3 was in critical need of reinforcement or it would soon fail. This
was EWB-UMN’s third implementation in the area, and first implementation in the
community. For our next implementation we hope to have a more widespread impact on the
system because the last implementation was so focused on helping a specific cohort of the
community. For this reason, improvement of the ram pumps was chosen as EWB-USA UMN’s
next implementation in Guatemala because of their widespread impact on the existing system
and the community.
The current system allows farmers to grow crops during the normally unproductive dry
season. Before, many farmers had to travel to the coast or other regions of the country to find
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 14 of 58
work during the dry season. Now they are able to find work within the community year-
round. This has allowed what once was subsistence farming to turn into a commercial
venture. Currently the APROMAC has Q7000 per pump and Q200, 000 per dam invested into
the system, and is therefore the greatest beneficiary to any improvements done on it. However,
expanding the system will extend benefits to other members of the community who were not
able to use the system before. There are several people in the community who would like to
utilize the system but are unable because their crops are too far from the water source for the
current pump capacity. By increasing the output specs of the ram pump design, we hope to be
able to allow farmers to join the system that were not able to at the time of its creation. Adding
our changes to the system we estimate will cost approximately Q245 per pump, a very small
amount when compared to the cost of a new pump.
3. Program Background
The University of Minnesota has worked in the Comalapa/San Juan region since 2006. During
this time two implementation projects have occurred (a spring box and pump in Chimiya, and a
rain water harvesting system (RWHS) in Simajhuleu). In August 2011 we visited a new
community, Agua Caliente, to meet with community members and gather preliminary
assessment data.
3.1 Project Partners
Long Way Home (LWH). “LWH is a non-profit organization which uses sustainable design and
materials to construct a self-sufficient school that promote education, employment and
environmental stewardship”, and is based out of Comalapa, Guatemala. EWB-USA UMN has
been partnered with LWH for several years and has worked with them to install a spring box and
pump in Chimiya, a rainwater harvesting system in Simajuleiu, and most recently a dam repair in
Agua Caliente. They have continued to work with us as translators, planners, and advisors
throughout the Agua Caliente project.
Asociacion de Desarrollo Integral de Productores de Mora Agua Caliente (APROMAC). The
APROMAC is a farming cooperative that has funded the irrigation dam and ram pump system
that is located on the stream leading from Patzá. They are forward-thinking and community-
minded, and have shown a lot of interest in working with EWB-USA UMN. Although they
already have an irrigation water system, much of it was designed without the aid of engineers
and is quickly falling apart, thereby causing erosion and becoming a danger to their investment
and lifestyle.
COCODE. The COCODE is the official local leadership board which oversees the community,
including the chlorinated drinking water system of Agua Caliente. Some members of the
COCODE are also members of the APROMAC, and both groups seem interested in working
with EWB-USA UMN to improve their irrigation system. Though EWB-USA UMN is not
working in direct relationship with the COCODE authorities, the president of the COCODE is a
member of the APROMAC and we continue to listen to COCODE members for suggestions or
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 15 of 58
community-wide goals.
EWB-USA MN Professional Group. Once every three months during 2013, the EWB-USA MN
Professional group will attend a EWB-USA UMN project meeting and will offer assistance to
our designs and methodology. The EWB-USA MN Professional group will also provide
mentorship to our group and will act as a reference for structural designs. EWB-USA UMN has
a very strong relationship with this group.
3.2 Community Description
Agua Caliente is composed of 200 families and is located on the Rio Agua Caliente. The total
population of the community is estimated to be around 1400 people, which averages around
seven people per family. There are two schools, a basic school and a middle school, but no
health clinic or market. For trade or for serious medical problems they go to the neighboring
villages of Simajahuleu or Poaquil, and if necessary, to the city of Comalapa. Their political
system is typical of others in the area and is composed of an Alcaldes and a COCODE.
Twenty years ago the community used to sell wood and carbon products but, after noticing the
rate of deforestation, decided to look for a more sustainable source of income. In response, 70
families organized to create a farming cooperative called the APROMAC, which also helped to
improve the health of their crops and protect them from larger buyers by selling crops as a
group. Since 1990, the APROMAC has successfully installed five irrigation dams, with several
ram pumps on each dam, in the stream that leads from Patzá. This enables them to irrigate their
crops in the dry season and, as an added benefit, creates several agricultural jobs for the
community as a whole. They have asked EWB-USA UMN to partner with them to protect the
integrity of the irrigation dams, to help them to improve and expand the ram pumps, and to
possibly add water storage for micro-irrigation in the future.
EWB-USA UMN has decided to define the APROMAC as our community and work with them
apart from the rest of the community of Agua Caliente for several reasons. First, the members of
the APROMAC have invested the most time and money into the irrigation system and
collectively own all of the dams and most of the ram pumps. Second, the APROMAC has
shown a lot of interest in working with EWB-USA UMN to improve the quality of the system
and is willing to provide labor and materials for an implementation. Third, the APROMAC
desires to expand the system to include as many families as possible, thus helping the entire
community of Agua Caliente.
3.3 Community Priorities
The APROMAC has invested a substantial amount of time and money into the current irrigation
system and their top priority is to protect their investment from being degraded or destroyed,
such as by a heavy rainfall. Once this prerequisite is met, the APROMAC has expressed interest
in the following projects, listed in descending order from most important to least important
(approximately, according to APROMAC leaders during the first two assessment trips):
1. Ensure that the dams will not be destroyed in a high rainfall event.
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Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 16 of 58
2. Replace the current system of sprinklers with water storage tanks and micro-
irrigation pipes. This will allow farmers to use less water, which will further allow
them to water more fields in a day than they are currently capable of or water multiple
fields at once.
3. Add more pumps, and therefore families, to the dams. This will allow more fields
to be watered.
4. Improve ram pump efficiency and pumping power. This will allow more fields to
be reached and will shorten the time required to water a field or fill a water storage
tank.
5. Replace the current black rubber hosing that connects the ram pumps to the
sprinklers with PVC or another, stronger material. The current range of some pumps
is limited because the rubber hoses break under pressure, and by switching to PVC
more fields will gain access to water.
6. Install a tilapia pond. This will provide the community with an alternative source
of meat.
3.4 Water Sources
There are at least two sources of water that the community uses. One is a hot spring, Patzá,
which flows into the Rio Agua Caliente, and the other comes from a neighboring stream.
Potable drinking water for the community is provided from the neighboring stream and is
chlorinated, and based upon community feedback the water is perfectly safe to drink. However,
there are some community members, especially the elderly, who do not like the taste of the
chlorination and continue to boil their water before drinking. The stream that runs from Patzá is
used primarily as agricultural water, although there have been reports of people swimming,
doing laundry, and letting animals drink from the stream.
3.5 Community Relations
During the repair and monitoring trip for the rainwater harvesting system in Simajhuleu, the
community of Agua Caliente learned about our presence in the area and approached Long Way
Home with interest in working with our group. EWB-USA UMN took a day trip to Agua
Caliente during this trip to see the agricultural system for the first time. We took our first
assessment full assessment trip in March 2012 to examine the system and meet with leaders from
the APROMAC and Agua Caliente. Our primary tasks included: a GPS survey of the
surrounding area; measurement of ram pump efficiency, flow rate, and power; measurement and
analysis of the structure of the dams and their stability; measurement of the spring safe yield
leading from the spring; estimate of the agricultural demand of the community; survey of the
types and acreage of crops that are fed by the irrigation system; testing and qualification of water
and soil at the river and in the fields; conduction of approximately 20 community surveys to gain
community opinion of the APROMAC and to determine the needs of the community.
From the first assessment trip it became clear that two of the dams, hereafter referred to as Dam
2 and Dam 3, were in danger of collapse. To gather more data we took a second assessment trip
in August 2012. Our primary tasks included: a more extensive GPS survey of the surrounding
area; a land survey of the area surrounding the dams, especially Dam 3; conduction of another 25
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 17 of 58
community surveys, bringing the total number of community surveys to 45; further water and
soil testing and qualification, especially around Dam 3; analysis of the hydrologic structure
surrounding the dams.
Currently, EWB-USA UMN is working towards our second implementation in Agua Caliente.
The following pages outline the methodology that EWB-USA UMN used to determine the nature
of our second implementation.
4. Facility Design
4.1 Description of the Proposed Facilities
This proposal is for increasing the efficiency of the ram pumps in Agua Caliente, Guatemala.
APROMAC, a blackberry co-op in Agua Caliente has created a system of five dams, each
supplying head to ram pumps used to irrigate fields during the dry season. EWB-USA UMN has
already completed one implementation on this system to fortify dam 3, and is now focusing on
increasing the supply distance of APROMAC’s pumps. Improved pumps will supply more water
to the fields currently irrigated by the system and allow more fields to be irrigated, which will
open the potential for additional families to join APROMAC.
The current APROMAC pump design consists of a drive pipe, air chamber, impulse valve, check
valve, and ram body. Water flows from the higher elevation behind the dam, through the drive
pipe and around the impulse valve. As the water reaches a certain velocity, the drag force on the
impulse valve becomes greater than the restoring force and the impulse valve shuts. The sudden
pressure spike caused by the impulse valve shutting causes the check valve between the ram
body and the air chamber to open, and water is pushed through the air chamber and into a supply
hose up to a certain delivery height. Two very crucial parameters of the impulse valve are the
restoring force and the distance the valve is allowed to open, called the stroke. The current ram
pumps used by APROMAC use boot rubber as the restorative force, which is unreliable. The
rubber wears out quickly and is not adjustable as the stroke and restorative forces can’t be
changed. The check valve is the other moving part of the pump. The current check value used by
APROMAC uses the water’s upward force to bend a very thick piece of tire rubber allowing
water to flow around it.
The impulse valve is the easiest piece of the current design to modify from both a monetary and
technical standpoint. Designing a new impulse valve will keep the upgrade cost per pump low
making the pump more affordable and, thus, giving more families the opportunity to upgrade or
join APROMAC. Experimental results showed that a tunable impulse valve with a three inch
impulse valve stopper would allow each pump to be optimized for its’ specific drive pipe length,
head and delivery elevation, thus, allowing each family to get the optimum performance out of
their existing irrigation system. Several educational workshops will be held with existing and
potential APROMAC members to demonstrate how to construct, tune and maintain the new
valve design. The estimated per cost per new impulse valve is thirty-five U.S. dollars, which is
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 18 of 58
just a small fraction of the total cost of a ram pump. Therefore, we hope that most members of
the community will find this design change very cost-effective.
As well as holding educational workshops for the proper construction and tuning of the newly
designed impulse valve, we plan on talking to the community about the potential for
implementing a drip irrigation system. If the community expressed interest in a drip irrigation
system, it would be a community-led implementation, and we would only serve to ask Toro to
donate the necessary materials. We also plan on asking the community if they have any interest
in organic farming, and potentially adapting to organic farming practices.
4.2 Experiment Design Background
Since hydraulic ram pumps are hard to analyze and predict with theory, we had to take a more
qualitative approach to redesigning the impulse valve. Also, since we could not exactly replicate
the current system in the community, and because the system in the community varies so much
from pump to pump, we decided to compare the flow rate between a replica of the valve
currently used in the community, and two valves EWB-USA UMN designed instead of
comparing the results to data from the ram pumps operating in the community. Therefore, we
had to design and build an impulse valve that would closely match the community’s current
design to test and compare with the other impulse valve designs EWB-USA UMN created.
Because we had to approach this in a qualitative manner, we decided to do some research on
what types of valves have been used in other hydraulic ram models. The two considerations we
took into account while designing the impulse valve were the ability to tune the valve and the
simplicity and ruggedness of design. We wanted a valve that is easy to maintain and last for a
long time, and that is easy to properly tune. One of the major problems with the current impulse
valve design in the community is that there is no way to properly tune the stroke length. The
spring force is tunable, but the rubber springs wear out very quickly and need to be replaced
every two weeks.
The two most common impulse valve designs use a spring as the restoring force, and weights as
the restorative force. For simplicity of construction and ease of maintenance and tuning, we
decided to go with an impulse valve design that uses weight as the restoring force. Because of
that, we had to run the impulse valve slider rod vertically, so we also introduced a ninety degree
elbow to the current design. This is a very common impulse valve design, and has been utilized
in many commercial ram pumps. Next, we were tasked with designing this impulse valve such
that the design facilitates constructing it properly, making sure that the slider rod runs coincident
with the center of the impulse valve hole, and that the impulse valve stopper seats square on the
underside of the impulse valve plate. We came up with a simple and efficient design laid out in
the next section.
4.3 Design of Experiment
The performance of hydraulic ram pumps is a function of several variables making it very
complex to predict analytically. Therefore, we decided early on in this project that we needed to
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 19 of 58
approach this project empirically, as there was no way we could analyze the existing pump and
decide what to change to make it perform better. As discussed above in section 4.2, we chose
two new types of impulse valves, based on commercial designs, to test against their current
impulse valve design.
We were fortunate enough to obtain lab space at the St. Anthony Falls Laboratory (SAFL) at the
University of Minnesota. Working in this versatile hydrology and fluid mechanics research
laboratory allowed us to take water indirectly from the Mississippi River, and then send it back
into the river. Other lab spaces we were considering would have required us to design and build a
water return system to conserve water, but at SAFL all the water is simply returned to the
Mississippi River.
There are several factors that affect the flow rate of a ram pump with a given impulse valve
design. Such factors include the height of the supplied water, the height of the delivered water,
and the impulse valve tune settings, which include the stroke and the added weight of the
impulse valve. To determine which impulse valve pumps the highest flow rate of delivered
water, we held the supplied water and the delivered water height constant throughout our testing,
and varied the tune settings. We used a statistical analysis to determine the best combination of
the stroke and weight for maximum output flow rate for a given impulse valve. The supplied
water and delivered water height were not chosen to represent the conditions in the community;
the supplied water height was constrained by our lab space, and the effective delivered water
height was chosen as an appropriate height to which they could potentially be pumping. We were
not concerned with these values as long as they were in an appropriate range. The purpose of this
experiment is to compare the results within the experiment, and not with the results of the pumps
in the community.
The only metric we are using for analysis outcomes is the delivered flow rate. The power and the
efficiency of a ram pump are two common parameters to examine, but we decided that are only
concern was producing the most amount of flow at the output. It has been shown in past
experiments that the maximum flow rate does not correlate to the maximum efficiency [2].
Therefore, due to the fact that the efficiency and the power are not necessary metrics in our
analysis, and the complications involved in making the necessary measurements, we decided to
only measure the output flow rate. We did this by inferring the flow rate from the weight of
water pumped in one minute.
4.4 Experimental Methods
A detailed experimental procedure is outlined below. We have tested and analyzed the two new
impulse valve designs and the replica of the current impulse valve design being used in the
community. The experimental procedure is very similar between the different valves, with the
only difference being that the two new valves use weights and the current design uses a rubber
spring.
1. Set the correct restoring force for the trial we are running.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 20 of 58
a) For the weights, weigh the combinations of the added weights and add them to the top of
the slider rod.
b) For the spring, the restoring force is defined as the force in the spring when the valve
stopper was approximately 1/8” open. Attach a force gauge connected to the slider rod and hold
at the position defined above. Clamp the two sides of the rubber spring onto the back side of the
flange and measure the force. If the tension needs to be adjusted, make the rubber tighter or
looser and then clamp it down and measure again.
2. Set the correct stroke for the trial to be run. This was done by adjusting a nut on the slider rod
that limited the motion of the slider rod and ultimately the valve stopper.
3. Add the correct size snifter plug.
4. Cover the impulse valve and snifter with splash covers.
5. Slowing turn on supply water flow until water flows out the impulse valve gently. Once water
starts to flow out impulse valve, turn water supply on all the way, such that the valve is wide
open.
6. Close throttle valve to allow air chamber to build up pressure. At the beginning, manually
pump the impulse valve if it is not running on its own.
7. Once the pressure gauge shows 60 psi, start to slowly crack open the throttle valve allowing a
small stream of water to flow out. Fine tune the throttle valve such that the maximum pressure
spike hits 60 psi.
8. Once the pump reaches steady operation, allow the delivered water to flow into a five gallon
for one minute, recorded with a stop watch. During that minute, record the number of cycles as
well.
9. After collecting the delivered water for one minute, turn the supply valve off all the way and
close the throttle valve all the way before the pressure drops too much. Observe the pressure
gauge to make sure the pressure is maintained in the air chamber. If the pressure is not
maintained in the air chamber, that would be a possible symptom of the check valve
deteriorating.
10. Open the throttle valve to release the pressure stored in the air chamber.
11. Measure the weight of the water and the bucket together, and then of the bucket all by itself
to determine the weight of the water alone.
4.5 Results and Discussion
The experiment was analyzed using Minitab software in order to fit a model to the data. All
terms (linear, squared, and interaction) were included in each analysis. Any term with a p-value
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 21 of 58
less than 0.050 was considered to be a significant factor. The delivered water weight was used
as the response.
4.5.1 VALVE #1
The stroke, valve weight, and both of their squared terms were found to be significant. The
interaction term was found to be insignificant. An R-squared value of 86.21% shows that the
model fits the data well. However, two trials varied significantly from the model. Upon
examination of the data, one trial had a very low response that can likely be attributed to a small
stroke length. Since the stroke length in that trial is considered to be unrealistic and far out of the
actual operating range, the data was re-analyzed excluding this trial. Detailed results from this
analysis can be seen in Appendix C.
Again, the stroke, valve weight, and both of their squared terms were found to be significant
while the interaction term was insignificant. The R-squared value improved to 97.33% which
means the model still fits the data very well. One trial varied significantly from the model but
was kept in the analysis due to the excellent fit. The residual plots show that the data is normal
and that there is no evidence of nonconstant variance or error correlation. A response
optimization analysis produced expected optimal values of a 1.78-in stroke length and a 2.88-lb
valve weight. Using these values, the predicted water delivery is 27.2lb. Detailed results from
this analysis can be seen in Appendix C.
Raw Data for Valve #1.
P-Values for all terms.
Trial Stroke (in)
Valve Weight
(lb)
Delivered Water
Weight (lb)
1 2.50 1.00 15.00
2 0.50 1.00 11.00
3 0.50 4.05 18.50
4 2.50 4.05 20.90
5 0.19 2.46 3.70
6 2.90 2.52 23.96
7 1.50 0.38 12.22
8 1.50 4.62 19.32
9 1.50 2.54 25.48
10 1.50 2.54 26.28
11 1.50 2.54 26.85
12 1.50 2.54 27.50
13 1.50 2.54 26.75
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 22 of 58
Critical Values.
4.5.2 VALVE #2
The stroke and valve weight were found to be significant. Both squared terms and the
interaction term were found to be insignificant. An R-squared value of 80.00% shows that the
model fits the data fairly well, and no trials varied significantly from the model. The residual
plots show that the data is normal and that there is no evidence of non-constant variance or error
correlation. The relationship between the stroke and the valve weight is linear, and therefore
optimal values for these factors could not be found. A linear relationship across all ranges is not
expected; it is more likely that the output will level off or begin to decrease outside of the range
that was tested. If the relationship were linear, a significantly higher stroke length and valve
weight would be required in order to achieve an output comparable to that of valve #1, and these
conditions would be impractical for this design. If the output levels off or begins to decrease, it
is unlikely that the maximum possible output is comparable to that of valve #1. Therefore, no
further testing was done on this valve. Detailed results from this analysis can be seen in
Appendix C.
Raw Data for Valve #2.
Term P-value
Stroke 0.013
Valve Weight 0.001
Stroke*Stroke 0.002
Valve Weight*Valve Weight 0.000
Stroke*Valve Weight 0.564
R-squared Value 97.33%
Optimal Stroke Length 1.78 in
Optimal Valve Weight 2.88 lb
Expected Delivered Water 27.2 lb
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 23 of 58
P-values for all terms.
4.5.3 VALVE #3
The original designed experiment for this valve called for a spring tension of approximately 50
lbs to be tested. During testing, while a spring tension of up to 52 lbs could be achieved, the
pump did not run above 48 lbs. The R-squared value for the model was 38.93%; however, one
trial varied significantly from the model. The data was re-analyzed excluding this trial. The
remaining data is normal, although weakly so (p-value of 0.055). The R-squared value improved
to 73.81%. While this indicates that the model is fair, the model does not appear to be reliable
above 45 lbs of spring tension. Even if the model were in fact accurate, it predicts that a spring
tension above 45 lbs would be required to reach an output comparable to valve #1. Since it is
already known that the valve will not operate at that level, no further testing was done on this
valve. Detailed results from this analysis can be seen in Appendix C.
Raw Data for Valve #3.
Trial Stroke (in)
Valve Weight
(lb)
Delivered Water
Weight (lb)
1 1.25 3.02 5.64
2 1.25 3.02 6.50
3 1.25 3.02 6.20
4 1.25 3.02 7.72
5 1.25 3.02 8.16
6 1.25 3.02 8.52
7 0.50 1.52 4.40
8 0.50 4.54 6.70
9 2.00 4.54 9.56
10 2.00 1.52 6.18
11 1.25 0.88 4.68
12 1.25 5.12 11.20
13 0.19 2.99 4.14
14 2.31 2.99 10.58
Term P-value
Stroke 0.005
Valve Weight 0.003
Stroke*Stroke 0.819
Valve Weight*Valve Weight 0.739
Stroke*Valve Weight 0.699
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 24 of 58
P-values for all terms.
4.5.4 Discussion
As discussed above, we expect that our new design (impulse valve three) will increase the
pumping capacity of the ram pumps in the community. Along will pumping more water, the new
valve will be much easier to tune properly. We found in our experimental runs of the ram pump
that it was very easy to add more weight to the new valve design, but it was very difficult to
increase the tension in the rubber consistently, especially without a force gauge. We expect that
our new valve design will make the tuning process much simpler and quicker. Another problem
with the current design is that the horizontal slider rod can easily bind in the bearing if the rubber
spring is pulling more on one side than the other when the valve is fully shut. This event
completely stopped the pump while we were testing it. This can be avoided by lubricating the
slider rod or make the bearing a looser fit. However, there will be more wear on the slider rod
and the bearing, and it would require regular lubrication. We expect that our new design will
decrease the rate of wear on the slider rod and bearing. Also, in our experimental trials the slider
rod never got caught in the bearing, which could have stopped the pump. Qualitatively, our new
impulse valve is a more robust design which facilitates the tuning process. Quantitatively, we
Trial Stroke (in)
Spring Tension
(lb)
Delivered Water
Weight (lb)
1 1.00 30.00 8.58
2 1.00 48.00 8.48
3 2.50 45.00 10.96
4 2.50 33.00 11.92
5 1.80 28.00 10.00
6 1.80 52.00 DID NOT RUN
7 2.80 40.00 9.92
8 1.80 38.00 5.78
9 1.80 38.00 9.36
10 1.80 38.00 9.78
11 1.80 38.00 9.32
12 1.80 38.00 9.58
13 1.80 38.00 10.64
14 0.70 37.00 15.40
15 1.80 50.00 DID NOT RUN
Term P-value
Stroke 0.061
Spring Tension 0.079
Stroke*Stroke 0.011
Spring Tension*Spring Tension 0.082
Stroke*Spring Tension 0.030
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 25 of 58
expect to potentially double the flow rate of the pumps in the community with our new impulse
valve design.
4.6 Drawings
See attached PDF for ram pump CAD designs.
4.7 Names and Qualifications of Designers
Name Student or
Professional
Qualifications Work Done
Nick Bodette Student Senior mechanical
engineering student
Design and build of ram model,
leader of ram pump group,
principal lab tech.
Kim Haglund Professional R&D Engineer Design of experiment, data
analysis, mentor
Becca Herron Student Junior Computer
engineering student,
project co-lead
Lead writer on EWB documents,
started ram pump project, helped
with lab testing
Tom Johnson Professional Professional
mechanical engineer
Designed impulse valve
Isaac Murphy Student Senior Mechanical
Engineering student
Designed the CAD drawings,
helped with pump testing
4.8 524 - Draft Final Design Report Comments
Project Design/Technical Description Comments:
No. Pg.
No.
EWB-USA PM Comment Chapter Response
1 You are building a demonstration pump at the
site for farmers to duplicate – is this correct?
This is correct.
2 All material (bar none) must come from
locally. All tools and equipment used to
assemble must be available locally.
Everything is available locally.
3 18 I understand that it will be the responsibility
of each individual who wants a pump to pay
for a construct his own pump – is this correct.
It seems like $625 is a high cost for a pump –
can anyone in the community afford this?
$500 is for pipe already there. The valve is
just $35 - $50.
4 What is the difference between this pump and
the existing pump in terms of water delivered?
What is the improvement?
Same head – higher flowrate. Also higher
head available.
5 Much of existing pipe for each pump can stay
the same.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 26 of 58
Next Steps Comments:
No. EWB-USA PM Comment Chapter Response
1 When do you plan on implementing? March? Yes.
2 When do you plan on submitting your 525 pre-
implementation report? December deadline?
Yes.
3 I will not call you after you submit your 525 pre-
implementation report. You will just be scheduled
for a TAC meeting.
Discussed.
5. Construction Plan Our methods for construction are based primarily around allowing the community to observe the
entire process: design of the valve, assembly of the valve, assembly with the pump, and tuning
the valve on the pump. In order to do this well EWB-UMN is designing a series of workshops
that involve machining from raw materials, demonstrating the valve on land, demonstrating
adding the valves to the existing pumps, and showing community members how to tune the
pumps. The existing design does not allow for any tuning whatsoever, but EWB-UMN’s
improved valve design allows for tuning based on stroke length, stroke force, and snifter size.
This allows for maximum pumping capacity for a variety of different needs whether that is high
elevation pumping or distance pumping. Below is a basic schedule for the workshops and
meetings with the community.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 27 of 58
Time March
14th
March
15th
March
16th
March
17th
March
18th
March
19th
March
20th
March
21st
March
22nd
March
23rd
7:30
AM
Travel
Day Intro
meeting
with
APROM
AC
Build
impulse
and
check
valves
for ram
pumps
Meet
with
communi
ty
members
intereste
d in
joining
system
Demonst
rate
valve
design on
land and
answer
questions
about
assembly
and
materials
.
Replace
valves in
streambe
d
Demonst
rate in
streambe
d
performa
nce to
communi
ty
members
Meet
with
communi
ty to
discuss
future
plans/pro
jects
Continge
ncy Day
Travel
Day
8:30
AM
9:30
AM
10:30
AM
Meet
with
APROM
AC to
discuss
where to
add
members
to system
11:30
AM
Build
impulse
and
check
valves
for ram
pumps
Test the
valve to
make
sure it
works in
country
Educate
possible
recipient
s of
valve
improve
ment
Tune ram
pumps in
streambe
d with
new
valves
12:30
PM
1:30
PM
2:30
PM
Demonst
rate in
streambe
d
performa
nce to
communi
ty
members
3:30
PM
4:30
PM
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 28 of 58
6. Materials List and Cost Estimate
Materials
4in Flange 20 $12 $240
4in Elbow 5 $15 $75
4in Pipe 3ft $5 $15
Bolt 85 $0.80 $68
Washer 160 $0.33 $53
Nut 100 $0.40 $40
Rubber Gasket 10 $5 $50
Threaded Rod 7 ft. $1.50 $11
Extra Rubber 2ft^2 $5 $10
Metal Bushing 5 $1 $5
Metal Weights 30 $1 $30
Total $596
7. Sustainability This project is highly sustainable for the community of Agua Caliente as it is simply an effort to
make improvements to a system originally and independently created by the citizens of the
community. By successfully building the system and continually using it over the last 30 years,
the community has demonstrated their capacity to maintain and repair their current system with
minimal outside support.
The model ram pump with the newly designed valves was constructed in Minnesota for testing
using only materials that are readily available for use in Agua Caliente. As a result, any materials
necessary for repairs to the system will be easily accessed by the community. This ensures that
the project will be highly sustainable for the community of Agua Caliente. If not for the lack of
engineering knowledge in the community, the system would be entirely sustainable without any
outside help apart from welding. For this reason EWB-USA UMN will hold a series of
workshops in Agua Caliente demonstrating the installation of new ram pump valves in order to
educate and enable community members to make adjustments and repairs to the system as
necessary. Sufficient time will be allowed for community members to ask questions to further
understand how the new design works. EWB-USA UMN will also provide the community with
detailed graphics and instruction manuals for future reference on the repair and installation of the
new valves.
This system has already proven to be financially and ecologically sustainable for the community
by their 30 year use of the system. The community has experienced significant financial benefits
as a result of the irrigation from the use of ram pumps and the installation of the new valves will
only further increase the financial sustainability of the system. The system of ram pumps in use
by the community has had minimal impact on their surrounding environment. The installation of
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 29 of 58
the new valves will not change this impact and will maintain the ecological sustainability of the
system.
7.1 Background
The community of Agua Caliente has a coop called APROMAC which grows blackberries as a
commercial crop in both wet and dry season and sells to a middle man from Miami. They are
able to do this because the water from an irrigation system they built allows them to grow higher
quality product and produce in two seasons. This allows them to skip a step in the purchasing
chain and make more money for their product rather than selling their crop in a market. The
community’s irrigation system uses a system of five irrigation dams on el Rio de Agua Caliente
to provide head to a set of ram pumps off of each dam. This allows the community to use the
river water to irrigate their crops in the dry season, providing an extra growing season in the
community. On an earlier implementation, dam 3 was determined to be in severe structural
disrepair. Dam 3 was successfully reinforced by erecting buttresses on the sides of the dam to
prevent a failure as well as adding a key and a toe onto the front of the dam. In the community
there are currently 42 ram pumps on the 5 dams, and our group has determined that these pumps
are not run at their maximum efficiency. APROMAC has asked EWB-UMN to protect and
improve their system, and therefore the step following structurally securing the dams was
working on the ram pumps. For this reason, we are testing two EWB-UMN designed valves and
a replica of the existing community valve to create a simpler, more tunable design. EWB-UMN
hopes to bring their more efficient design to the community to demonstrate the better valve so
people can use it with their ram pumps. EWB-UMN will demonstrate how to install and tune
their valves with the existing pumps so the community can build and implement the valves for
their own pumps with the knowledge from the workshops.
7.2 Operation and Maintenance
Along with the five year monitoring plan EWB-USA UMN provides, there are many things that
the community can do to ensure proper working order of the ram pumps. Before placement of
the ram pump pipes into the stream at the beginning of the dry season, it would be ideal to grind
off rust and apply a corrosion protecting paint if readily available and affordable for the
community. Another way to prevent any malfunctions of the ramp pump is to have a filtering
system at the intake of the drive pipe. This will stop any debris from entering the intake of the
pipe and flowing into the ram pump. Having a filter with the correct filter size is imperative so
that the flow of water is not impeded by debris such as twigs, leaves, plastic bottles, etc. To make
sure that the efficiency of the ram pump stays very high, maintaining the correct snifter size is
key so that the air levels in the air chamber stay consistent. If any valves of the ram pump break
and become dysfunctional, they need to be changed as fast as possible to ensure the correct
operation of the pump. The valves can be easily fabricated by the owners of the ram pumps
within the community. The pumps should also be properly tuned so that they are working at the
optimal efficiency. The ram pumps owners will be taught how to tune the ram pumps during the
workshops, so they will be able to tune them on their own.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 30 of 58
7.3 Education
7.3.1 Workshops and Community Interaction
During this implementation trip, EWB-USA UMN will hold a series of workshops
demonstrating to the members of Agua Caliente how to properly build and tune our newly
designed valves for their ram pumps. When arriving on site, the travel team will build and run
the new impulse valve design, without community members, to ensure the valve runs as
predicted. They will then hold a workshop teaching the community how to assemble and install
the new impulse valves so the community will be able to replicate the design and process in the
future. This workshop will also explain, in detail, why it is necessary to assemble the valve
according to the provided procedure, as well as why the new design is more powerful than the
current system. An additional workshop will be held educating the community on the
importance and procedure of properly tuning the ram pumps to maximum flow rate. In addition
this workshop will demonstrate proper maintenance techniques that will ensure proper ram pump
operation. Both workshops will utilize an existing ram pump to demonstrate the improved
impulse valve. By giving special attention to the building process, the workshops will allow the
community members to have the necessary knowledge to ensure replication and sustainability of
the new valve design. By encouraging the community to follow our design and construction
techniques, we can improve the longevity and minimize down-time of the pumps and the system.
When in country, a manual, translated into Spanish, will be left with the community. This
manual will contain specific instructions on proper design, assembly and tuning procedures of
the new impulse valve. The manual will also include a list of potential complications that may
occur and how to properly resolve them. By leaving the community with the proper education
and a manual, EWB-USA UMN will provide the community the necessary tools to build and
maintain the new valves after we are gone. The time spent educating the community on proper
ram pump construction, in addition to the manual, will allow the community to reproduce the
same results and sustain the system for a long period of time.
7.3.2 Introducing New Farmers to the System
In order to introduce new farmers to the system, we will teach them how to utilize a throttle
device along with an existing pump near them. To test whether or not someone’s farm can now
utilize the system, the farmer would borrow their neighbor’s optimized ram pump. They will put
a throttle device on the delivery output which is set with the added pressure of the height
difference between the field utilizing the system and the field being potentially added. The
farmer will re-optimize the pump at the added pressure and see if it has a consistent output at the
increased pressure. If the pump outputs water with the throttle and the existing height, then the
new farmer will be able to utilize the system with the new pump design.
7.3.3 Measuring the Increased Output of Existing Pumps
For the people with existing ram pumps, we teach them the following process in order to
calculate their increased usage output:
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 31 of 58
1. Measure the flow rate of the existing valve at the height of one of their fields.
2. Exchange the existing valve for the elbow and new weight-based valve we are teaching
the community how to build.
3. Measure the flow rate of the new valve at the same height as the first valve, but with
varying stroke length and weight to figure out the maximum flow rate for the given
delivery head. This will be tested based on similar trials to the trials EWB-UMN
executed in a lab setting.
4. Run the pump at the optimum tune settings to demonstrate to the community that by
tuning the ram pump you can achieve a higher flow rate at a given delivery height with
the new valve design.
7.3.4 Introducing New Delivery Height to Community
EWB-UMN will take several steps in order to demonstrate to the community that the new valve
can reach a higher delivery height.
1. Throttle the pump in the stream bed to simulate increased delivery heights and tune the
pump for maximum output flow at each delivery head setting.
2. Bring the throttle device up to a field currently supplied by a ram pump. EWB-UMN
will measure the maximum flow rate at the given height, then throttle the output to a
higher simulated height to demonstrate that the community could pump to a higher field
than currently possible because of the ability to tune.
3. Bring the delivery hose of an existing ram pump up to a height where it can no longer
output water. Switch the existing valve to the new valve, tune the valve, and demonstrate
that the tunable valve can still output water, albeit a smaller amount of water.
4. There will be some heights where the maximum flow rate at the output is too minimal to
be useful to farmers. We will establish with the community what the minimum
sustainable daily quantity of water is, and determine where this amount is able to be
pumped to.
8. Signed Implementation Agreement While this agreement isn’t yet signed with the community, we will sign it with the leaders of the
community through our NGO Long Way Home before arrival for implementation.
Engineers Without Borders
University of Minnesota-Twin Cities Chapter
Minneapolis, Minnesota
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 32 of 58
1 March 2013
APROMAC de Agua Caliente
Agua Caliente, Guatemala
Regarding: The Acquisition, Improvement, Operation, and Maintenance of Ram Pumps.
This contract is an agreement on the improvement and maintenance of the ram pumps in Agua
Caliente between APROMAC and Engineers Without Borders University of Minnesota-Twin
Cities Chapter (EWB-UMN). Engineers Without Borders and APROMAC will undertake the
stated responsibilities for the acquisition, improvement, and monitoring process.
APROMAC will:
Provide 2 laborers for construction of the ram pumps.
Provide preparation for the demonstration drive pipe whether a disassembled pump from
a member of the community, a drive pipe built from spare parts, or a drive pipe purchased
and welded before EWB-USA UMN’s arrival in country.
Choose key members of the community to attend all workshops provided by EWB-USA
UMN about the design of improved ram pumps.
Be responsible for purchasing materials for and assembling their own valves to improve
their own ram pumps.
Continue having monthly contact with Engineers Without Borders about updates in the
community, maintenance of the system, and future coordination with EWB-UMN
Regularly follow the monitoring procedure provided by Engineers Without Borders to
preserve the integrity of the ram pumps and perform repairs.
Engineers Without Borders will:
Provide and cover the cost of the materials for construction of a demonstration ram pump
and build the demonstration with the help of the APROMAC workers.
Plan and provide a series of workshops demonstrating how to build, tune, and maintain
the ram pumps.
Provide educational materials for reference for the community to continue utilizing the
technology once EWB-USA UMN leaves the community.
Continue to maintain monthly contact with the community to discuss maintenance of the
EWB-UMN implementation and preparations for future coordination.
Provide the community with a maintenance plan for the sustainability and longevity of
the system.
Monitor the ram pumps for 5 years and be responsible for repairing any damage directly
resulting from design or structural flaws.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 33 of 58
Both Engineers Without Borders and APROMAC will uphold their stated responsibilities or the
implementation of ram pumps could be at risk delayed. At the time of construction a monitoring
agreement will be signed.
________________________ ________________________
President of APROMAC Student Lead of EWB UMN
________________________ ________________________
Vice President of APROMAC Professional Lead of EWB UMN
9. Site Assessment Activities Trips prior to this have yielded quite a bit of information we have needed to perform many of our
calculations and designs. Most of this data has been quantitative like measuring the flow rate and
pressure in several of the ramp pumps on the dams. Also, we assessed all of the five downs in
Agua Caliente to see which dam was in the worst condition and needed to be repaired. These
calculations include the amount of water held behind the dam, the physical size of the dam, and
the condition seeing if there are any cracks, erosion, or seepage underneath the dam. On the
larger scale, we took GPS points around all the dams so that we could map the terrain. This was
important to calculate the water shed for the whole Agua Caliente valley to know how rain
affected the water level. Another significant part of prior assessments was to actually survey the
community, including the people in and outside of APROMAC. These questions included
whether or not they owned a pump on any of the dams, the size of their farms, and the amount of
water they used need to supply to their land.
10. Professional Mentor Assessment
10.1 Professional Mentor Name and Role
Kim Haglund, lead mentor for ram pump testing.
10.2 Professional Mentor Assessment
Three valve designs were tested in order to determine which design produces the highest amount
of delivered water. It is impractical to test the ram pumps under the same conditions that are
found in-country. Therefore, a design similar to the pump used by the community was built
along with two proposed improvements to the design. These three pumps are tested under the
same conditions so that a relative comparison can be drawn. Despite the difference in
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 34 of 58
conditions, any relative improvements that were seen during the experiment should also extend
to the usage conditions.
A designed experiment was created in order to test the effects of stroke length and valve weight
on the delivered water from each pump design. Response Surface analyses of the data generated
models for each design in order to predict the optimal values for each factor and the expected
amount of water delivered from a design that uses the optimal values. One of the valve designs
clearly showed that its predicted water delivery is higher than the other two designs, including
the design that most closely replicates the design used in-country. The group plans to implement
the corresponding design changes on five ram pumps in the community, and educate the
community on the tuning effects to the design so that they can implement the design on other
pumps and effectively maintain the new design.
10.3 Professional Mentor Affirmation
I agree with the experimental method presented in this report and I recommend the
implementation of design changes to the community’s ram pumps according to the changes that
were made to valve #1.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 35 of 58
Appendix A – Existing System Pictures
A.1 Check Valve
Above are pictures of the check valve or one way valve of the existing ram pumps. Water comes
up through the holes and underneath the rubber flap in the picture to the right. When the
pressure underneath the valve becomes negative, the rubber quickly shuts against the holes and
no water is let through. This allows the pump to produce water up gradients.
A.2 Waste Valve
Above you can see pictures of the existing impulse valve slider rod. The design in guatemala
consists of a metal rod with a thick piece of rubber and a metal plate attached to the end. This
plate slams shut when the pressure of the water flowing past the valve and out the output
becomes greatere than the spring or weight force holding it open. Our design currently has the
same function without the rubber, creating a sharper impulse and a therefore more intense
pressure wave with less energy loss.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 36 of 58
Above are pictures of the exsisting waste valve. You can see the four pieces of metal welded to
the end of the body of the ram, making a structure to stabalize the waste valve slider rod. There
are several loops welded to the body as well, which provide tie-offs for the rubber strips that the
community currently uses for their waste valve force.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 37 of 58
Pictures of the functioning in-country waste valve.
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University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 38 of 58
A.3 Air Chamber
A view inside the air chamber of the ram. As you can see, water is forced up the small interior
pipe, and the air cushon sits in the space above the internal pipe and below the top of the air
chamber.
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University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 39 of 58
A.4 Exemplary Existing Pumps
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
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Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 40 of 58
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 41 of 58
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 42 of 58
Appendix B – Lab Testing
The pump being built in the shop.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 43 of 58
Assembling the body of the ram.
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University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 44 of 58
The output of the ram, where the waste valve goes.
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University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 45 of 58
The testing facility and the drive pipe.
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University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 46 of 58
Nick tightening the output. For testing purposes we put a valve on the output to simulate
pressure and measured it with a pressure gauge.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 47 of 58
Nick tightening the output valve with the pump fully assembled. In the bottom of the picture the
waste valve can be seen. The discs are the variable weights we used for the valve. The structure
on top of the flange is the guide for the slider rod.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 48 of 58
Appendix C – Analysis of Experimental Design
VALVE #1
DATA ANALYSIS
Response Surface Regression: Delivered Water (lb.) versus Stroke (in), Valve Weight (lb.) The analysis was done using coded units.
Estimated Regression Coefficients for Delivered Water Weight (lb.)
Term Coef SE Coef T P
Constant 26.3190 1.622 16.223 0.000
Stroke (in) 4.6408 1.313 3.534 0.010
Valve Weight (lb.) 3.0264 1.273 2.377 0.049
Stroke (in)*Stroke (in) -6.1252 1.462 -4.189 0.004
Valve Weight (lb.)*Valve Weight (lb.) -4.7482 1.363 -3.484 0.010
Stroke (in)*Valve Weight (lb.) -0.4783 1.785 -0.268 0.796
S = 3.63084 PRESS = 624.748
R-Sq. = 86.21% R-Sq.(pred) = 6.63% R-Sq.(adj) = 76.36%
Analysis of Variance for Delivered Water (lb.)
Source DF Seq SS Adj SS Adj MS F P
Regression 5 576.849 576.849 115.370 8.75 0.006
Linear 2 218.942 240.688 120.344 9.13 0.011
Stroke (in) 1 144.598 164.610 164.610 12.49 0.010
Valve Weight (lb.) 1 74.344 74.467 74.467 5.65 0.049
Square 2 356.961 356.735 178.367 13.53 0.004
Stroke (in)*Stroke (in) 1 197.059 231.335 231.335 17.55 0.004
Valve Weight (lb.)*Valve Weight (lb.) 1 159.902 160.018 160.018 12.14 0.010
Interaction 1 0.946 0.946 0.946 0.07 0.796
Stroke (in)*Valve Weight (lb.) 1 0.946 0.946 0.946 0.07 0.796
Residual Error 7 92.281 92.281 13.183
Lack-of-Fit 3 90.033 90.033 30.011 53.40 0.001
Pure Error 4 2.248 2.248 0.562
Total 12 669.130
Unusual Observations for Delivered Water (lb.)
Delivered
Water
Obs StdOrder Weight (lb.) Fit SE Fit Residual St Resid
9 9 3.700 9.627 2.744 -5.927 -2.49 R
11 11 18.500 14.105 2.961 4.395 2.09 R
R denotes an observation with a large standardized residual.
- P-values show that stroke length and valve weight are both significant, but there is no interaction between
the two factors.
- R-squared value of 86.21% shows that the model represents the data well.
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University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 49 of 58
- Observations 9 and 11 appear to be unusual. Upon examination of the data, Observation 9 had a very low
response that was likely due to the very low stroke length. We decided to re-analyze the data without this
trial to see if the model improves.
DATA ANALYSIS (EXCLUDING TRIAL 5)
Response Surface Regression: Delivered Water (lb.) versus Stroke (in), Valve Weight (lb.) The analysis was done using coded units.
Estimated Regression Coefficients for Delivered Water (lb.)
Term Coef SE Coef T P
Constant 26.5051 0.5881 45.067 0.000
Stroke (in) 2.1145 0.6007 3.520 0.013
Valve Weight (lb.) 3.0038 0.4611 6.514 0.001
Stroke (in)*Stroke (in) -3.5654 0.6471 -5.510 0.002
Valve Weight (lb.)*Valve Weight (lb.) -5.7344 0.5139 -11.158 0.000
Stroke (in)*Valve Weight (lb.) -0.3951 0.6466 -0.611 0.564
S = 1.31483 PRESS = 99.8028
R-Sq. = 97.33% R-Sq.(pred) = 74.29% R-Sq.(adj) = 95.10%
Analysis of Variance for Delivered Water (lb.)
Source DF Seq SS Adj SS Adj MS F P
Regression 5 377.785 377.785 75.557 43.71 0.000
Linear 2 89.936 94.879 47.439 27.44 0.001
Stroke (in) 1 18.440 21.418 21.418 12.39 0.013
Valve Weight (lb.) 1 71.496 73.353 73.353 42.43 0.001
Square 2 287.204 287.207 143.604 83.07 0.000
Stroke (in)*Stroke (in) 1 71.939 52.491 52.491 30.36 0.002
Valve Weight (lb.)*Valve Weight (lb.) 1 215.265 215.253 215.253 124.51
0.000
Interaction 1 0.645 0.645 0.645 0.37 0.564
Stroke (in)*Valve Weight (lb.) 1 0.645 0.645 0.645 0.37 0.564
Residual Error 6 10.373 10.373 1.729
Lack-of-Fit 2 8.125 8.125 4.062 7.23 0.047
Pure Error 4 2.248 2.248 0.562
Total 11 388.158
Unusual Observations for Delivered Water (lb.)
Delivered
Water
Obs StdOrder Weight (lb.) Fit SE Fit Residual St Resid
13 13 15.000 16.711 1.048 -1.711 -2.15 R
R denotes an observation with a large standardized residual.
- P-values show that stroke length and valve weight are both significant, but there is no interaction between
the two factors.
- R-squared value of 97.33% shows that the model represents the data very well.
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 50 of 58
- Observation 13 appears to be unusual, but since the data is still modeling well, we chose to include this trial
in the analysis.
210-1-2
99
90
50
10
1
Residual
Pe
rce
nt
25201510
1
0
-1
-2
Fitted Value
Re
sid
ua
l
1.51.00.50.0-0.5-1.0-1.5
3
2
1
0
Residual
Fre
qu
en
cy
13121110987654321
1
0
-1
-2
Observation Order
Re
sid
ua
l
Normal Probability Plot Versus Fits
Histogram Versus Order
Residual Plots for Delivered Water (lb)
- Normal Probability Plot: points along the line show that the data is normal
- Histogram: shows there is no evidence of skewness or outliers
- Versus Fits: random scattering of data shows no evidence of nonconstant variance
- Versus Order: random scattering of data shows no evidence of error correlation
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 51 of 58
Stroke (in)
Va
lve
We
igh
t (l
b)
2.52.01.51.00.5
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
>
–
–
–
–
< 5
5 10
10 15
15 20
20 25
25
(lb)
Weight
Water
Delivered
Contour Plot of Delivered Water (lb) vs. Valve Weight (lb), Stroke (in)
- Data points show the combinations that were tested
- Darkest green area shows optimal values
Response Optimization Parameters
Goal Lower Target Upper Weight Import
Delivered Water (lb.) Maximum 23 28 28 1 1
Global Solution
Stroke (in) = 1.77768
Valve Weight (lb.) = 2.87558
Predicted Responses
Delivered Water (lb.) = 27.1825 , desirability = 0.836494
Composite Desirability = 0.836494
- The optimal values for this valve design are a stroke length of 1.78in and a valve weight of 2.88lb. This
combination is expected to result in a response of 27.2lb of delivered water.
VALVE #2
525 - Pre-Implementation Report 12-15-2013
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Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 52 of 58
DATA ANALYSIS
Response Surface Regression: Delivered Water (lb.) versus Valve Weight (lb.), Stroke (in) The analysis was done using coded units.
Estimated Regression Coefficients for Delivered Water (lb.)
Term Coef SE Coef T P
Constant 7.1071 0.5190 13.694 0.000
Valve Weight (lb.) 1.8464 0.4482 4.119 0.003
Stroke (in) 1.7168 0.4495 3.819 0.005
Valve Weight (lb.)*Valve Weight (lb.) 0.1608 0.4666 0.345 0.739
Stroke (in)*Stroke (in) -0.1106 0.4677 -0.237 0.819
Valve Weight (lb.)*Stroke (in) 0.2534 0.6314 0.401 0.699
S = 1.27139 PRESS = 53.4689
R-Sq. = 80.00% R-Sq.(pred) = 17.32% R-Sq.(adj) = 67.51%
Analysis of Variance for Delivered Water (lb.)
Source DF Seq SS Adj SS Adj MS F P
Regression 5 51.7375 51.7375 10.3475 6.40 0.011
Linear 2 51.1738 51.0067 25.5034 15.78 0.002
Valve Weight (lb.) 1 27.5495 27.4309 27.4309 16.97 0.003
Stroke (in) 1 23.6243 23.5758 23.5758 14.59 0.005
Square 2 0.3033 0.3033 0.1516 0.09 0.911
Valve Weight (lb.)*Valve Weight (lb.) 1 0.2129 0.1920 0.1920 0.12 0.739
Stroke (in)*Stroke (in) 1 0.0904 0.0904 0.0904 0.06 0.819
Interaction 1 0.2604 0.2604 0.2604 0.16 0.699
Valve Weight (lb.)*Stroke (in) 1 0.2604 0.2604 0.2604 0.16 0.699
Residual Error 8 12.9314 12.9314 1.6164
Lack-of-Fit 3 6.1087 6.1087 2.0362 1.49 0.324
Pure Error 5 6.8227 6.8227 1.3645
Total 13 64.6689
Estimated Regression Coefficients for Delivered Water (lb.) using data in uncoded
units
Term Coef
Constant 1.73379
Valve Weight (lb.) 0.520525
Stroke (in) 2.10483
Valve Weight (lb.)*Valve Weight (lb.) 0.0714681
Stroke (in)*Stroke (in) -0.196654
Valve Weight (lb.)*Stroke (in) 0.225269
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University of Minnesota
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Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 53 of 58
210-1-2
99
90
50
10
1
Residual
Pe
rce
nt
1210864
1
0
-1
Fitted Value
Re
sid
ua
l
1.51.00.50.0-0.5-1.0-1.5
4.5
3.0
1.5
0.0
Residual
Fre
qu
en
cy
1413121110987654321
1
0
-1
Observation Order
Re
sid
ua
l
Normal Probability Plot Versus Fits
Histogram Versus Order
Residual Plots for Delivered Water (lb)
- Normal Probability Plot: points along the line show that the data is normal
- Histogram: shows there is no evidence of skewness or outliers
- Versus Fits: random scattering of data shows no evidence of nonconstant variance
- Versus Order: random scattering of data shows no evidence of error correlation
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University of Minnesota
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Valve Weight (lb)
Str
oke
(in
)
54321
2.0
1.5
1.0
0.5
>
–
–
–
–
< 4
4 6
6 8
8 10
10 12
12
(lb)
Water
Delivered
Contour Plot of Delivered Water (lb) vs Stroke (in), Valve Weight (lb)
- Data points show the combinations that were tested
VALVE #3
DATA ANALYSIS
Response Surface Regression: Delivered Water (lb.) versus Spring Tension (lb.), Stroke (in) The analysis was done using coded units.
Estimated Regression Coefficients for Delivered Water (lb.)
Term Coef SE Coef T P
Constant 9.2988 0.9011 10.319 0.000
Spring Tension (lb.) -0.6429 0.9869 -0.651 0.536
Stroke (in) -0.2731 0.8350 -0.327 0.753
Spring Tension (lb.)* -0.8187 0.9889 -0.828 0.435
Spring Tension (lb.)
Stroke (in)*Stroke (in) 1.7724 0.8882 1.996 0.086
Spring Tension (lb.)*Stroke (in) -0.4238 1.1835 -0.358 0.731
S = 2.23802 PRESS = 712.923
R-Sq. = 38.93% R-Sq.(pred) = 0.00% R-Sq.(adj) = 0.00%
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University of Minnesota
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Analysis of Variance for Delivered Water (lb.)
Source DF Seq SS Adj SS Adj MS F P
Regression 5 22.3489 22.3489 4.4698 0.89 0.534
Linear 2 0.8448 3.0885 1.5443 0.31 0.744
Spring Tension (lb.) 1 0.4499 2.1255 2.1255 0.42
0.536
Stroke (in) 1 0.3949 0.5357 0.5357 0.11 0.753
Square 2 20.8618 21.2827 10.6414 2.12 0.190
Spring Tension (lb.)*Spring Tension (lb.) 1 1.4885 3.4332 3.4332 0.69
0.435
Stroke (in)*Stroke (in) 1 19.3733 19.9454 19.9454 3.98 0.086
Interaction 1 0.6422 0.6422 0.6422 0.13 0.731
Spring Tension (lb.)*Stroke (in) 1 0.6422 0.6422 0.6422 0.13
0.731
Residual Error 7 35.0611 35.0611 5.0087
Lack-of-Fit 2 20.8615 20.8615 10.4308 3.67 0.104
Pure Error 5 14.1995 14.1995 2.8399
Total 12 57.4100
Unusual Observations for Delivered Water (lb.)
Delivered
Obs StdOrder Water (lb.) Fit SE Fit Residual St Resid
2 2 8.480 9.433 2.188 -0.953 -2.03 R
R denotes an observation with a large standardized residual.
Estimated Regression Coefficients for Delivered Water (lb.) using data in uncoded
units
Term Coef
Constant -2.61101
Spring Tension (lb.) 1.13772
Stroke (in) -8.56747
Spring Tension (lb.)* -0.0145546
Spring Tension (lb.)
Stroke (in)*Stroke (in) 3.15101
Spring Tension (lb.)*Stroke (in) -0.0753387
DATA ANALYSIS (EXCLUDING TRIAL #2)
Response Surface Regression: Delivered Water (lb.) versus Spring Tension (lb.), Stroke (in) The analysis was done using coded units.
Estimated Regression Coefficients for Delivered Water (lb.)
Term Coef SE Coef T P
Constant 8.872 0.6405 13.851 0.000
Spring Tension (lb.) 2.995 1.4157 2.116 0.079
Stroke (in) -1.788 0.7750 -2.307 0.061
Spring Tension (lb.)* 3.199 1.5308 2.090 0.082
Spring Tension (lb.)
Stroke (in)*Stroke (in) 2.347 0.6453 3.637 0.011
Spring Tension (lb.)*Stroke (in) -4.781 1.6959 -2.819 0.030
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 56 of 58
S = 1.54918 PRESS = 42.8202
R-Sq. = 73.81% R-Sq.(pred) = 22.11% R-Sq.(adj) = 51.98%
Analysis of Variance for Delivered Water (lb.)
Source DF Seq SS Adj SS Adj MS F P
Regression 5 40.5777 40.5777 8.1155 3.38 0.085
Linear 2 2.6359 14.4187 7.2093 3.00 0.125
Spring Tension (lb.) 1 0.0891 10.7431 10.7431 4.48
0.079
Stroke (in) 1 2.5468 12.7726 12.7726 5.32 0.061
Square 2 18.8705 36.3084 18.1542 7.56 0.023
Spring Tension (lb.)*Spring Tension (lb.) 1 0.2744 10.4791 10.4791 4.37
0.082
Stroke (in)*Stroke (in) 1 18.5961 31.7522 31.7522 13.23 0.011
Interaction 1 19.0713 19.0713 19.0713 7.95 0.030
Spring Tension (lb.)*Stroke (in) 1 19.0713 19.0713 19.0713 7.95
0.030
Residual Error 6 14.3998 14.3998 2.4000
Lack-of-Fit 1 0.2002 0.2002 0.2002 0.07 0.801
Pure Error 5 14.1995 14.1995 2.8399
Total 11 54.9775
Unusual Observations for Delivered Water (lb.)
Delivered
Obs StdOrder Water (lb.) Fit SE Fit Residual St Resid
8 8 5.780 9.086 0.632 -3.306 -2.34 R
R denotes an observation with a large standardized residual.
Estimated Regression Coefficients for Delivered Water (lb.) using data in uncoded
units
Term Coef
Constant 35.0388
Spring Tension (lb.) -2.37821
Stroke (in) 14.8829
Spring Tension (lb.)* 0.0568648
Spring Tension (lb.)
Stroke (in)*Stroke (in) 4.17253
Spring Tension (lb.)*Stroke (in) -0.849882
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 57 of 58
20-2-4
99
90
50
10
1
Residual
Pe
rce
nt
161412108
0
-2
-4
Fitted Value
Re
sid
ua
l
210-1-2-3
7.5
5.0
2.5
0.0
Residual
Fre
qu
en
cy
151413121110987654321
0
-2
-4
Observation Order
Re
sid
ua
l
Normal Probability Plot Versus Fits
Histogram Versus Order
Residual Plots for Delivered Water (lb)
- Normal Probability Plot: points along the line show that the data is normal
- Histogram: shows there is no evidence of skewness or outliers
- Versus Fits: random scattering of data shows no evidence of nonconstant variance
- Versus Order: random scattering of data shows no evidence of error correlation
525 - Pre-Implementation Report 12-15-2013
University of Minnesota
Agua Caliente, Guatemala
Expanding Agricultural Opportunities
© 2013 Engineers Without Borders USA. All Rights Reserved Page 58 of 58
Spring Tension (lb)
Str
oke
(in
)
5045403530
2.5
2.0
1.5
1.0
>
–
–
–
< 10
10 20
20 30
30 40
40
(lb)
Water
Delivered
Contour Plot of Delivered Water (lb) vs Stroke (in), Spring Tension (lb)
- Data points show the combinations that were tested
Appendix D – Cited Sources [1] Eshenaur, Walter C. A Theoretical Computer Based Model for Use in Design of Hydraulic
Ram Water Pumps. Thesis. University of Minnesota, 1985. N.p.: n.p., n.d. Print.
[2] Watt, S. B. A Manual on the Hydraulic Ram for Pumping Water. N.p., n.d. Web.
[3] Welch, Michael. Things That Work! The Folk Ram Pump. Home Power, n.d. Web.