Hands-on Activity: Tippy Tap Plus Piping
Educational Standards :
Pre-Req Knowledge (Return to Contents)
Students must have a basic knowledge of algebra, exponents, and how to use mathematical formulae. Prior exposure to the design process is required. (Note: If students are unfamiliar with the design process, refer to http://www.teachengineering.org/engrdesignprocess.php or TeachEngineering's Creative Engineering Design unit.
Learning Objectives (Return to Contents)
After this activity, students should be able to:
Materials List (Return to Contents)
Purchase the following items at any hardware or home improvement store (such as The Home Depot or Lowe's). Each group needs:
For the entire class to share:
Introduction/Motivation (Return to Contents)
You have been contacted by your local university's Engineers Without Borders program and asked to help them on a project. Through Engineers Without Borders, students work on projects that help communities around the world, not only now, but in the future as well. EWB is focused on sustainable projects for developing communities and educating the communities on all aspects of the systems. The EWB program works with two communities in Rwanda, Africa. In Mugonero, one of the communities, an orphanage is the home for kids as young as 4 or 5 and as old as 20. EWB needs your help to improve the sanitation and thus the overall health of children in this community.
About 38% of the world lacks access to improved sanitation (WHO, 2008), which makes it unlikely that hand washing occurs after bathroom use and before meals. Washing hands with soap has been shown to reduce the risk of diarrheal disease by 42-47% (Curtis, 2003), thus many people in less developed countries suffer from diseases that could be prevented if they had a way to wash their hands regularly. To this end, the Tippy Tap hand-washing station was developed and deployed in primarily rural areas of the developing world, such as Mugonero. The Tippy Tap (show students Figure 1 or the attached Tippy Tap Construction document) is a simple invention that enables hand washing without plumbing and with a fraction of the water used by a conventional/modern faucet with plumbing. This device is made from a jug that releases a small amount of water when tipped. Releasing the Tippy Tap causes it to swing back to its original position and stop the water flow. And, if a foot control is added, it becomes very hygienic because only the soap is touched.
One drawback of the Tippy Tap is that it must be refilled by hand. Filling is a simple task that involves unscrewing the cap and pouring in clean water from a reservoir. Although filling is not complicated or time intensive, children in Mugonero often forgo washing hands rather than refill the Tippy Tap. This is especially problematic in high-traffic areas where the tap needs to be refilled often.
Our engineering challenge is to design a piping system that enables the Tippy Tap to be more easily and efficiently filled, thus eliminating the need to hand carry water to the device and manually fill it. We want our piping system to enable water to efficiently flow from a stationary reservoir (a five-gallon bucket) located behind a small obstruction to the Tippy Tap. As part of your design, you and your team will choose pipe, fittings, valves and tubing to enable filling of the Tippy Tap, yet still allow it to rotate and dispense water.
You will follow the steps of the engineering design process to create this device. The first step is already done, which is to identify the need. Next, we'll be brainstorming solutions, deciding on our best ideas, constructing a prototype, and testing it. Let's get started!
Vocabulary/Definitions (Return to Contents)
Procedure (Return to Contents)
Water is required for human survival and thus the necessary and creative transport of water has been occurring for thousands of years. This is just one example of how engineers have always made a world of difference! Water may be transported with aqueducts, pipelines, canals, tunnels and various other means. Transporting water is very energy intensive, so engineers who create water-moving systems are always concerned about efficiency. In piping systems, several phenomena affect the efficient flow of water:
Engineers, therefore, always try to minimize piping system components that hinder the flow, and are constantly looking for new and innovative ways of increasing and using hydrostatic head to transport water with a minimum expenditure of energy.
In this open-ended design project, student teams design, build and test piping systems that enable water to flow from a five-gallon bucket (representing a water source, such as a rainwater catchment holding tank) to the Tippy Tap. They use elbow-style fittings or some other method to route the piping systems in non-direct paths to the Tippy Tap — similar to how engineers encounter and work around the unique obstacles that are found in all real-world projects. They choose pipe, fittings, valves and tubing to enable filling of the Tippy Tap, yet still allow it to rotate and dispense water (therefore, rigid connections are not acceptable).
This service-engineering project works well and engages students, even if you don't have an actual client. However, we have noticed that students of both genders and all ethnicities tend to respond with more enthusiasm and interest in real-world projects with actual clients. In lieu of creating a piping system for a faraway community, which may be unrealistic to arrange, consider taking the time to find a local client, such as a scout troop, summer camp organization, remote ranch/farm, or rural recreational area, for which the project would be a useful device.
Before the Activity
With the Students – Day 1 (50 minutes)
With the Students – Day 2 (50 minutes)
With the Students – Day 3 (50 minutes)
Attachments (Return to Contents)
Safety Issues (Return to Contents)
Troubleshooting Tips (Return to Contents)
Open-ended design projects can be difficult for students because no clear path to one solution exists. Keep students on task, working towards a feasible design, watching that they do not get stuck wasting too much time brainstorming or building unrealistic designs.
Investigating Questions (Return to Contents)
During testing of their piping systems, have students consider the following questions:
Assessment (Return to Contents)
Discussion Questions: Stimulate discussion regarding clean water availability in the developing world and the engineer's role in facilitating its availability. Ask the students:
Activity Embedded Assessment
Activity Handout: The Fluid Dynamics Basics Handout is a self-contained tutorial on the fundamentals of fluid flow with 11 homework problems. First, lead an in-class discussion about the material discussed in the handout, then have students work through the content and instructions provided in the handout, and assign the questions as homework.
Concluding Discussion: Use the following suggested questions to lead a concluding discussion for this activity. Ask the students:
Handout: As a homework assignment, have students answer the 11 questions in the Fluid Dynamics Basics Handout. Review their answers to gauge their understanding of the material.
Additional Multimedia Support (Return to Contents)
Take a look at a 2:16 minute video showing how to make a Tippy Tap; see "The Tippy Tap, a hand washing device with running water," at ( http://www.youtube.com/watch?v=P-Lk-GJtTbM)
For more information on high school engineering design process activities and projects, see TeachEngineering's Creative Engineering Design unit.
Learn more about the engineering design process at http://www.teachengineering.org/engrdesignprocess.php
References (Return to Contents)
Curtis, Val and Sandy Cairncross. May 2003. Effect of Washing Hands with Soap on Diarrhoea Risk in the Community: A Systematic Review. The Lancet Infectious Diseases. Vol. 3, pp. 275-281. http://www.cleantheworld.org/docs/CurtisHandwashing.pdf
Low-cost hand-washing technology. Last updated December 8, 2009. IRC International Water and Sanitation Centre. Accessed December 16, 2010. (Tippy Tap definition) http://www.irc.nl/page/13215
Progress on Drinking Water and Sanitation: Special Focus on Sanitation. 2008. World Health Organization, UNICEF, Geneva, New York; pp. 1-54. http://www.who.int/water_sanitation_health/monitoring/jmp2008/en/index.html
Tippy Taps: A design for simple, economical and effective hand-washing stations. Foodborne and Diarrheal Disease Branch, Centers for Disease Control and Prevention. Accessed December 16, 2010. (Construction, installation and maintenance instructions)http://www.cdc.gov/safewater/publications_pages/tippy-tap.pdf
Hygiene Challenges and Resources in Less Developed Countries. Last updated December 28, 2009. Centers for Disease Control and Prevention. Accessed December 16, 2010. http://www.cdc.gov/healthywater/hygiene/ldc/hygiene_challenges.html
ContributorsBenjamin S. Terry, Kaisa Wallace-Moyer, Stephanie Rivale, Denise W. Carlson
Copyright© 2010 by Regents of the University of Colorado.
Supporting Program (Return to Contents)Integrated Teaching and Learning Program, College of Engineering, University of Colorado at Boulder, University of Colorado Boulder
Acknowledgements (Return to Contents)
The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and National Science Foundation GK-12 grant no 0338326. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.