STEM Valve 1

Name / Date
Science / Class

STEM Challenge: Make a Valve

Water bottle cap / Faucet / Gas burner / Car cylinder

The world’s most common form of transportation may be the humble pipeline. Pipelines transport vast amounts of liquids and gases around the world, 24/7. Pipelines use valves to control how much fluid passes through them, and also to switch off the flow completely.

Here are some examples:

  • When you open and close a water bottle, you control the flow of water into and out of the bottle.
  • When you turn on a faucet, you open a valve that allows pressurized water to escape from a pipeline.
  • When you flush a toilet, you open two valves. One allows water to escape to empty the pan, and the other admits water into the tank to get ready for the next flush.
  • When you turn on a gas stove, you control how much gas exits to create a flame.
  • When you wash clothes, a valve controls the water supply and rinse cycle.
  • When you drive, valves admit air and fuel, and allow exhaust gases to escape.

Our focus for this STEM challenge is the human heart. Every time your heart beats, valves inside the heart allow it to pump blood either to the lungs, or to the rest of the body. Learn more about the valves of the human heart from the resources presented below.

Heart valves as seen from the top / Heart valves as seen from the side
Watch how heart valves work at (1:26 min)
Watch an animation of heart valve replacement at min)
Listen to an interview with a prominent surgeon who discusses three types of valve replacements-- biological, mechanical, and a new kind called sutureless.
min)
Note: Another design is called a “ball valve.” Check it out!
Biological Tissue Valve / Mechanical Valve / Perceval Sutureless Valve

Your STEM challenge is to design and construct a valve that will control the flow of water between two holding areas, A and B. We will use soda bottles with the ends cut off for these areas. Bottles A and B will be joined as shown. Your goal is to create a valve that fits into the joined area such that water will pour freely from A to B, but will not flow from B to A when the bottles are turned upside down. This valve will be similar to valves in the human heart work that work to keep blood flowing in one direction. “Success” will be measured by how well the valve works in each direction.

Materials

2 reservoirs, which will be the tops of two 2L soda bottles

A bowl large enough to catch water as it moves between A and B

1 ziplock bag, quart size

4 large paper clips

1 rubber ball, large enough to plug a bottle opening

1 square of plastic screening, approximately 23cm by 23cm

1 meter string

2 rubber bands

1 piece stiff plastic (e.g. ½ sheet protector) or 1 large balloon
25cm duct tape

3 medium brads

1 chenille stem (pipe cleaner)

hot glue

A beaker or graduated cylinder to measure the amount of water that passes through the valve

Group Responsibilities

  1. Group-- Your group will design and construct a valve.
  2. Individual #1-- You will measure and graph the effectiveness of your valve.
  3. Individual #2-- You will write about problems, solutions, and improvements.
  4. Individual Job3-- You will diagram your finished valve from the top and side views.
  5. Individual Job4-- You will demonstrate to the class how your valve works.

Source

Jenkins, Richard. "How Cars Work The Workings Of A Car Explained."How Cars Work - The Workings Of A Car Engine Explained. N.p., n.d. Web. 14 Apr. 2017.

"Mechanical Heart Valve."Mechanical Heart Valves - Types: Ball Valves. N.p., n.d. Web. 14 Apr. 2017.

Woodford, Chris. "How Valves Work | Types of Valves."Explain That Stuff. EXPLAINTHATSTUFF!, 24 Oct. 2016. Web. 14 Apr. 2017.

Image Sources

Image of faucet at

Image of gas burner at

Image of heart (top view) at

Image of heart (side view) at