Automatic Bell Siphon Explained

Automatic Bell Siphon Explained

This is a demo of a bell siphon I built in collaboration with a couple of engineering professors. There are certain cases where it would be nice to be able to create a siphon without any intervention, a self-priming or automatic siphon: the next level of siphonry. It’s built out of an acrylic sheet and a piece of clear pipe. Thanks to Rolf Hut and Pete Marchetto for inviting me to collaborate on their project.

Full Project: https://www.youtube.com/watch?v=71E52Mbj32s&t=48s
Big Clive Urinal Auto-Syphon: https://www.youtube.com/watch?v=BQ45kMi6HkA
Rolf Hut: http://rolfhut.nl/english
Pete Marchetto: https://about.me/pete.marchetto
Animation: Devin Sloan

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50 Comments

  1. @thisguy916 on February 4, 2024 at 5:55 am

    aquaponics mentioned, WOOOOOOOOOOOOOOOOOOOOO



  2. @PracticalEngineeringChannel on February 4, 2024 at 5:55 am

    A lot of people have been commenting about the fluid tension theory of siphons. A siphon can indeed function without ambient air pressure in specific circumstances, but the bell siphon is relying on air pressure. More info in paragraph 5, here: https://en.wikipedia.org/wiki/Siphon#Theory



  3. @kellycarner4472 on February 4, 2024 at 5:56 am

    Atmospheric pressure has nothing to do with a siphon, suction on the other hand has everything to do with it if the suction breaks the siphon stops, if the point is lower the the fluid will continue to flow.



  4. @nateb4543 on February 4, 2024 at 5:56 am

    You’re telling me for emptying rainwater from my tarp i won’t get pine needles or worms in my mouth? Sign me up!



  5. @Steven_Rowe on February 4, 2024 at 5:57 am

    Your right big Clive tried to work out how a urinal bell siphon worked but a real explanation has been done which is fascinating indeed
    Check out the video
    https://youtu.be/3So7W34KNV8



  6. @joycehendry3595 on February 4, 2024 at 5:59 am

    I would love to be able to siphon water upwards It would save me the tedious task of using a jug to pour water into my fish tank after siphoning out the dirty water



  7. @TheRealPlato on February 4, 2024 at 5:59 am

    thumbs up if you walked through San Francisco before they stopped punishing crime



  8. @heitorvieirafilho2643 on February 4, 2024 at 6:00 am

    Thank you God bless



  9. @charleshawkins34 on February 4, 2024 at 6:00 am

    If you hold a lit candle under a bell siphon does it force the heated air to expand into the cup? Working in reverse?



  10. @madzen112 on February 4, 2024 at 6:01 am

    I make siphons all the time



  11. @Upbeat_Impact on February 4, 2024 at 6:01 am

    Hi, if siphon can pull the water above uphill, why cant it be used to fill the upper reservoir in a Hydro Electricity set up ?



  12. @plumerault on February 4, 2024 at 6:02 am

    But isn’t a siphon made to empty a reservoir by its upper part ? The bell siphon looses this property it seems.



  13. @ErikssonTord_2 on February 4, 2024 at 6:04 am

    Lovely!



  14. @Dr.JustIsWrong on February 4, 2024 at 6:04 am

    Oh, you release the air down via siphon tube rather than up.



  15. @maciejnajlepszy on February 4, 2024 at 6:06 am

    So this is how the paria diving accident happened.



  16. @alan_5540 on February 4, 2024 at 6:07 am

    Basically your toilet flush at home



  17. @2000yearOldYogiAspirant on February 4, 2024 at 6:07 am

    Does the output of water still need to be at a lower altitude than the siphon?



  18. @gavin4981 on February 4, 2024 at 6:08 am

    Mhm



  19. @samadmohamad1251 on February 4, 2024 at 6:13 am

    خیلی عالی واموزنده..ممنون از تفهیم زیبای که انجام دادید



  20. @occamraiser on February 4, 2024 at 6:14 am

    clear and concise description of something that is obvious but I hadn’t seen before – even though I have heard urinals automatically flushing, I’d always assumed it was some form of hinged (tipping) tank in the reservoir. Thanks for the illumination.



  21. @jamesbond0004 on February 4, 2024 at 6:14 am

    nice Brady,



  22. @imnate on February 4, 2024 at 6:16 am

    My place of work uses this principle to flush the urinals automatically.



  23. @timurotolenkovski3780 on February 4, 2024 at 6:17 am

    Thx for upload!



  24. @benmildenberger1879 on February 4, 2024 at 6:20 am

    but wait, don’t you need to add water to the reservoire to start it? it isn’t really a self-priming siphon if it requires outside intervention now does it. Also, siphons are hoses/tubes that rest over the edge of the reservoir and run downhill whereas the bell siphon is like a spill valve on a water tank. This bell siphon thing isn’t a siphon by definition.



  25. @arcofblues on February 4, 2024 at 6:20 am

    Is this the same as the syphon in a house toilet?



  26. @yasarali45 on February 4, 2024 at 6:23 am

    Boyle’s perpetual motion flask canbe done bell ball syphon..??



  27. @obst3085 on February 4, 2024 at 6:24 am

    Didn’t see it so I’ll say it: a Soxhlet extractor in chemistry works that way too, you heat your solvent, it condenses into the Soxhlet, the hot solvent extracts the stuff you want and at some point the solvent gets sucked back to the original flask, meaning you enrich the solvent in what you want, and in the end you can just distill off the solvent to isolate your product. Did that in lab as a demo for fat content in hazel nuts.



  28. @TurtleSauceGaming on February 4, 2024 at 6:28 am

    thanks! I’m off to use a bucket and a tube to drain my neighbor’s pool



  29. @ronhollenbeck on February 4, 2024 at 6:28 am

    I specified an automatic bell siphon system a couple of times for septic systems. They were a bit finicky.



  30. @power21100 on February 4, 2024 at 6:31 am

    Sweet! Just what I need to make my wave maker for my reef tank



  31. @GaneshmanLamathinker on February 4, 2024 at 6:33 am

    Clear explanation 👌



  32. @lolitabonita08 on February 4, 2024 at 6:33 am

    but what about if i want to drain the water from a bucket underground to over a cinder block fence??? does this concept will work for that or maybe u have another idea. Problem…my racist back door neighbor build their fence with base cinder block blocking the natural flow of the water when it rains, my backyard floods and the water does not have any place to go. Paying someone to make a french drain is out my budget and it will very expensive because there are a couple of issues to deal with first and then do the drainage… so occurred to me if i can do buckets with some sort of drainage to their backyard (they will not even noticed because it is raining lol) so i can stop flooding of my property. Any ideas?



  33. @terra2468 on February 4, 2024 at 6:34 am

    sorry for the question but why to choose this way of flow instead a steady flow? when a bell siphon is more appropriate then regular flow?



  34. @whatever-pw3tj on February 4, 2024 at 6:34 am

    I like the channel I find it informative and relaxing.



  35. @user-te7zz8mv3x on February 4, 2024 at 6:35 am

    thank you so much for the demo and diagrams! i tried watching several videos previously and didn’t understand why the bell siphon worked for aquaponic systems … now i get it. thanks again!



  36. @jomercer21113 on February 4, 2024 at 6:36 am

    Oh! that’s what I have in the liquid detergent dispenser in my HD washing machine. I was wondering how that worked!



  37. @anilkumarsharma8901 on February 4, 2024 at 6:36 am

    Equation for bell siphon ?????



  38. @commandermudpie on February 4, 2024 at 6:36 am

    Vacuum is not at work. A siphon works on the moon (no atmosphere)



  39. @dennisgibbs5708 on February 4, 2024 at 6:39 am

    Thanks for your bell siphon example. I’d like to build one for a my 3” popup at the end of a French drain. Don’t know where to start? This would allow me slowly drain f-drain automatically the pipe without fancy electronics! Please help?



  40. @hartfordboothe7466 on February 4, 2024 at 6:39 am

    This is an interesting video. I’d never heard of a bell siphon before, it was neat to see how it works. If I may ask an irrelevant question: the 2D animations like at/around 1:00 in the video, with which software were they made? Thanks for the video.



  41. @TheJadekungfu on February 4, 2024 at 6:39 am

    Can the bell siphon bring water up to a higher elevation?



  42. @koaasst on February 4, 2024 at 6:40 am

    when youtube was in its infancy i learned how to build a complete aquaponic system, and still have a box in the garage with the old pvc bell siphons. blast from the past!



  43. @olsmokey on February 4, 2024 at 6:42 am

    I disagree with you on one point: it’s not a "vacuum", just an area of reduced pressure.



  44. @duniaproyek6943 on February 4, 2024 at 6:43 am

    Thanks for tutorial



  45. @madzen112 on February 4, 2024 at 6:43 am

    Friday night siphoning



  46. @dominantdaddy6939 on February 4, 2024 at 6:44 am

    I do believe I’m going to attempt to build one for my basement sumps. Why purchase expensive pumps if this will get the job done? Plus…if there is a storm and the power is out I’m screwed



  47. @Anderson-bk1hf on February 4, 2024 at 6:44 am

    You meant to say lungs and stomach full of gasoline 😂



  48. @carlbussmann7559 on February 4, 2024 at 6:46 am

    Another great self-explanatory and useful video by Grady. Also use flexible tubing immersed completely under the surface, block off the outflow end and release the blocked end into the lower container.



  49. @Hobo-J on February 4, 2024 at 6:46 am

    I love your video but you don’t explain how a bell siphon actually works



  50. @ThisHandleIsntTook on February 4, 2024 at 6:50 am

    👌