Book 25, Question 74 · Video
Why don't drains make your bathroom smell like the sewer?
Under each sink is a U-shaped pipe called a trap that always holds a little water. This water plug blocks smelly sewer gas from coming back up. Small vent pipes, often poking through the roof, let air into the drains so that they flow smoothly and the water in the trap does not get sucked out. If a drain is unused for months, the water can dry up.
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What Crafty Clover says in this video
Intro
Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why don't drains make your bathroom smell like the sewer?
The Big Idea
Drains connect to the stinky sewer. So why doesn't your bathroom smell? A clever bend in the pipe!
The Trap
Step one: The Trap. Under each sink is a U-shaped pipe called a trap. It always holds a little water.
Water Plug
Step two: Water Plug. This water plug blocks smelly sewer gas from coming back up. It works every time water drains.
Vent Pipes
Step three: Vent Pipes. Small vent pipes, often poking through the roof, let air into the drains so they flow smoothly. They keep the trap water from being sucked out.
A Closer Look
Let's take a closer look! Water goes down the sink. The trap bends. Water stays in the bend. Vents let air in.
Quick Facts
Quick facts! Pouring a little water down a rarely used drain refills the trap. Traps can dry out. Vents poke out of roofs. Traps can even catch a lost ring.
Think Like a Scientist
Now, think like a scientist! Bend a flexible straw into a U shape. Pour a little water into the bend. Blow gently into one end. See how the water blocks the air. How is this like a drain trap?
Outro
Drains don't make your bathroom smell because a U-shaped trap holds a water plug that blocks sewer gas, and vent pipes let air in so the trap stays full. Science is amazing! The world is full of surprises. Keep asking big questions, and keep exploring with me! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!