Make Your Own Balloon Pump

I recently met with a Girl Scout troop to chat about what my day-to-day looked like in a STEM career working on an offshore oil platform like the one shown on the left. Offshore oil differs from the land rig shown on the right. Yes, I saw fish out 100 miles off the coast of Louisiana and yes, I could feel my platform move occasionally like being rocked on a giant boat. (One of these days I should tell you the story about being offshore during a winter storm but that can be a different post on a different day! 😅)

Image by brgfx on Freepik

The troop and I had the most fun experimenting during our chat with science that we encounter everyday and how that same science exists offshore like how when oil is found underground in oil reservoirs. The oil will always float on top water under the ground too so we filled a bottle with vegetable oil and water to demonstrate what this looked like.

Next we discussed equipment that exists offshore and how we separate oil and water in separators. These separators can be ginormous as evident in the background of this picture! And yes, that’s me standing in front of my separator.

Separators operate under high pressure and use pumps to move the water away from the oil. Then we made our very own pump using a water bottle, balloon, and a straw. You can make your own balloon pump too for this activity!

Here’s what you need: water bottle, knife, straw, hot glue gun, and balloon.

Here’s how you do it: 

1. Cut a small hole in the side of the bottle with the knife (use adult supervision)
2. Insert a straw in the hole
3. Place hot glue around any openings to seal the straw to the bottle
4. Fill bottle with oil and water mixture and allow it to settle
5. Direct the straw to a separate container to catch the liquids
6. Place a balloon over the top to pump out the liquids

What’s the science? The inflated balloon has a higher air pressure than the air pressure inside the bottle. When the higher pressure balloon air enters the bottle’s air space, it pushes down on the liquid causing the liquid at the bottom of the bottle to escape to a lower pressure out of the straw. You can control the air by pinching off the neck of the balloon.

This was a great way to do a hands on activity to see what it’s like to work as an engineer in the oil industry. I hope this helps you plan your own STEM career talk too particularly during the upcoming Engineering Week!