YouTube: https://youtube.com/watch?v=_0bRBBYkA1k
Previous: The Last Major Smallpox Outbreak in America
Next: Sex Research: SciShow Talk Show

Categories

Statistics

View count:682,355
Likes:15,769
Comments:550
Duration:03:52
Uploaded:2017-12-05
Last sync:2024-03-02 02:45

Citation

Citation formatting is not guaranteed to be accurate.
MLA Full: "Why Don't Fire Hydrants Freeze and Explode?" YouTube, uploaded by SciShow, 5 December 2017, www.youtube.com/watch?v=_0bRBBYkA1k.
MLA Inline: (SciShow, 2017)
APA Full: SciShow. (2017, December 5). Why Don't Fire Hydrants Freeze and Explode? [Video]. YouTube. https://youtube.com/watch?v=_0bRBBYkA1k
APA Inline: (SciShow, 2017)
Chicago Full: SciShow, "Why Don't Fire Hydrants Freeze and Explode?", December 5, 2017, YouTube, 03:52,
https://youtube.com/watch?v=_0bRBBYkA1k.
Pipes can freeze in the winter, but you never hear about fire hydrants freezing. What makes them safe from the cold temperatures in winter time?

SciShow Finds: https://scishowfinds.com/

We're conducting a survey of our viewers! If you have time, please give us feedback: https://www.surveymonkey.com/r/SciShowSurvey2017

Hosted by: Hank Green
----------
Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow
----------
Dooblydoo thanks go to the following Patreon supporters: Kelly Landrum Jones, Sam Lutfi, Kevin Knupp, Nicholas Smith, Inerri, D.A. Noe, alexander wadsworth, سلطان الخليفي, Piya Shedden, KatieMarie Magnone, Scott Satovsky Jr, Bella Nash, Charles Southerland, Bader AlGhamdi, James Harshaw, Patrick Merrithew, Patrick D. Ashmore, Candy, Tim Curwick, charles george, Saul, Mark Terrio-Cameron, Viraansh Bhanushali, Kevin Bealer, Philippe von Bergen, Chris Peters, Justin Lentz
----------
Looking for SciShow elsewhere on the internet?
Facebook: http://www.facebook.com/scishow
Twitter: http://www.twitter.com/scishow
Tumblr: http://scishow.tumblr.com
Instagram: http://instagram.com/thescishow
----------
Sources:

http://www.todayifoundout.com/index.php/2014/08/reason-fire-hydrants-dont-freeze-winter/
http://media.cygnus.com/files/base/FHC/document/2011/09/weeklydrills34final_10461393.pdf
http://media.cygnus.com/files/base/FHC/document/2011/11/weeklydrills43final0_10457995.pdf
https://www.livescience.com/43408-why-do-freezing-pipes-burst.html
https://www.plumbingsupply.com/residential-water-pressure-explained.html
http://www.firehydrant.org/info/faqs_ask7.html
https://books.google.com/books?id=GUXyAAAAQBAJ&pg=PA495

Images:

https://en.wikipedia.org/wiki/File:Downtown_Charlottesville_fire_hydrant.jpg
https://en.wikipedia.org/wiki/File:Dry_hydrant.jpg
https://commons.wikimedia.org/wiki/File:Hydrant_Insel_Krk_Kroatien.jpg
https://commons.wikimedia.org/wiki/File:Hydrant_in_Jerusalem.jpg
https://commons.wikimedia.org/wiki/File:Berlin_hydrant_20050211_p1000517.jpg
https://en.wikipedia.org/wiki/File:1869BirdsillHollyHydrantSideTop.jpg
https://commons.wikimedia.org/wiki/File:Fire_hydrant_UK.jpg
If you live somewhere that gets below freezing in the winter, you’ve probably heard stories of water pipes bursting during cold weather.

It happened to my house one time. But you almost never hear about the same thing happening to fire hydrants.

Well, that is because we use different types of hydrants in different places, depending on how cold it gets. And the ones in cold places don’t have any water in them to freeze. Places with mild climates, like the southern US, tend to use what are called wet barrel fire hydrants.

Water from underground pipes flows all the way up into the tall, above-ground section of the hydrant, called the barrel, even when the hydrant’s not in use. When firefighters need water, they just turn a valve near the top, and it comes rushing out. But wet barrel fire hydrants would be terrible in places with colder winters, because freezing temperatures outside the barrel would freeze the water inside, too.

Water gets bigger when it freezes, so expanding ice inside a hydrant would push against the inside walls and squeeze any liquid water left in the hydrant, eventually making the hydrant crack or explode. This is why pipes burst in the winter: They’re not strong enough to withstand the pressure exerted by expanding ice. And it’s why wet barrel hydrants would explode in the winter, too, if we used them everywhere.

So to avoid that mess, dry barrel hydrants are used. As you might guess from the name, dry barrel hydrants are normally dry, meaning they don’t have any water in the barrel when they’re not in use. Instead, the water stays underground in water mains, which are buried below the frost line, the depth where temperatures don’t drop below freezing, even in the dead of winter.

In most places, that’s just a couple meters below your feet. In the U. K. and a few other countries, they take this to the next level, and they don’t have any part of the hydrant above ground at all.

All you see is a colorful marker or metal plate. When firefighters need water from a dry barrel hydrant, they turn a valve that lets water up into the barrel and out of the hydrant, just like with wet barrel hydrants. But then any water in the hydrant after use is drained, so there is no freezing water, and therefore no rupture.

It might seem like dry barrel hydrants would be useful everywhere, but they have a couple of downsides. Since part of the valve is so far underground, they can be harder to repair than wet barrel hydrants. And the fact that they’re basically empty when not in use can also be a problem, because things can be shoved inside them.

In cities, hydrants sometimes get clogged by people using them as makeshift trash cans. Which is why they’re not used everywhere. But in colder places like here in Montana, that is a small price to pay for hydrants that don’t catastrophically explode every winter.

EXCITING ANNOUNCEMENT! Here's the situation. The SciShow team and I were talking about a problem that we often have.

People will ask us what we want for Christmas, and we don't know what to say because what is stuff for anyway? It's so twentieth century. But then I was thinking, y'know, there are a few things that I would like to get, or that I have bought for myself, or that people have given me that I have loved because I love the world, and the universe, and the existence of life...

That kind of thing. So we put together a collection of artifacts of this universe. We got a limited number of each of those things, and we have put them in a store called SciShow Finds.

These SciShow Finds are curated by me, things that I know that I would love to get in my stocking. It's a very small list, just a few things with varying price points. We're probably going to add new finds as we find them throughout the year, and those new ones will replace these old ones, so all of these products are only around for a limited time.

You're bound to have friends or family who would love Mars Socks, or trilobite fossils, or this Space Shuttle lapel pin. And, if not, you might want to get them for yourself or just slide a link into your Mom's DMs so she can get you some socks that you'll actually appreciate this time. And know that when you buy from SciShowFinds.com, you are also supporting SciShow, which you are doing right now just by watching.

So, thanks.