How to Collapse a Pipe by Closing a Valve

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[PracticalEngineeringChannel]

What topics are you interested in for 2018? More fluid dynamics? Reinforced concrete? Geotechnical?

[AnarchistAaron]

Hey Grady, at the factory I work at we had a 50, 000 litre milk silo implode because the air inlet valve was blocked. It pulled a large vacuum then finally gave way. The resulting implosion blew the inward opening silo door off and dumped about 10, 000 litres of milk over the production hall floor. It had to be cut into 3 sections to remove it and took 2 cranes to lift it out and replace it. All because of 1 blocked valve

[ethernet]

Since I'm a student with no money I can't donate, but I think your channel is great. Def thumbs up every time.

[davidb]

Don't forget, blue pvc glue is for non pressure applications like drainage or vents. Use green pvc glue for higher pressure or vacuum applications. Love the channel!

[soylentgreenb]

On water mains they typically make it really difficult to close or open a valve quickly. If you have to turn ~50 whole turns you have to really try in order to damage anything.

[lieutenantdan]

As he said in the end of the video, yes, it is very important to close all valves on the fire trucks very slowly or you will risk breaking the pumps. Most of the trucks will be spraying water out in upwards of 100psi, so if you stop the water flow too fast you will most likely destroy every pipe on the truck and put it out of service for a few months. The only reason you should stop the flow quickly is if you start to lose control of the hose. And you did a great job explaining this, thank you from Manchester volunteer fire department

[MARKE]

As a Water Distribution Employee for a Water Utility we have 26 different Fire Departments within our system. Education is the key. Both Paid and Volunteer Firefighters love to open fire hydrants as fast as possible and in turn slam them closed. Every year we have to remind them over and over please open them slowly and close slowly if you have water flowing. They can create a water hammer at their pumps just as easily as they can at the hydrants. We even have to teach them what the pressure relief valve is for on their Fire Engine pump panels. Since my job is repairing the breaks, I see this problem never going away I will be including this video along with the positive water hammer video to all the Fire Depts hopefully they will watch and remember why slow and steady is best. Some of our infrastructure dates back to 1880. We only use USA made products and materials. Sadly it’s becoming difficult to find products. They are considering now using products made in Israel and Australia. Thanks again for making great videos

[PreloadedMind]

As a 6yr fire sprinkler service tech, I've known of these, but you using that crazy expensive clear PVC, really help me under stand the water vacuum so much more. Thanks man. I feel like I can now better explain to my customers what they are doing wrong. And have a vid I can direct them to.

[xWood]

I would have liked a practical demonstration of the implosion.

[preppingundkrisenvorsorge]

I am an volunteer firefighter from germany. Once we've made an exercise: we closed the valves from four waterhouses on the exactly same time, the house next to oure fireengine explodes! (before we closed the valves 2.050 litre/min on 12 bar pressure were gone out of the houses). On testings from the producer the houses held an minimum of 25 bar pressure.

Greetings from germany
(Please excuse my horrible english)

[plasmahead]

And you just solved a mental issue I've had with how fluid dynamics works... Thank You!

[TheMr]

Forms of concrete failure? ( too much sand or gravel, not enough curing time, etc)

[theyxaj]

I found this channel a couple of months ago, and every time I watch a video, I can't believe how cool it is. You're doing a fantastic job, Grady!

[saihenjin]

What about one on the formation of potholes?

[XPStartupSound]

"No offense to the backyard scientists" says the guy literally doing science in his backyard :)

Great video btw!

[Rsenior]

There cannot be more than 100kPa vacuum (0kPa absolute), by definition. The gauge only reads over 100 kPa due to inertia in the gauge components.

I'm surprised that small pipes would have a problem with 0kPa absolute, since the surface area is small. I would imagine large pipes would have a significant issue due to the surface area. Thoughts?

[jcnash]

As a fire fighter pumping an engine, I learned some interesting things related to this. Since we use an pump (not just system pressure), we have to be careful, that we “feel” how firm our supply line from the hydrant is so we can avoid pulling more water than the water system can supply. Also, fire hydrants require many turns to close the valve to prevent us accidentally opening/closing it too quickly which would cause problems for the municipality or whomever is supplying the water system. What is also interesting is that in dry sprinkler systems, we use a very small pressure of air to hold the valve closed against much higher pressures of water. It’s around 5:1 ratio. Maybe you could do a video talking about how this works?

[LectronCircuits]

Years ago, we used to "water hammer" our house via its upstairs bathroom lever-action faucet. We never popped the pipes, but it was fun. Cheers!

[seannov]

This is honestly one of my favorite youtube channels, I'm in my second year as a mechanical engineering major and am loving all of these cool fluid dynamics videos. Thank you!

[alext]

Gradys a youtuber who has an acute awareness of youtube itself. Thats one of the reasons I love this channel.