How gas pumps know when to turn themselves off 

Steve Mould
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Gas or petrol pump nozzles turn off automatically when your tank is full. The way it works is really clever and uses the venturi effect.
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Steve Mould
Steve Mould 年 前
If I've set things up right, the title of this video should say "gas" for US people, and "petrol" for UK people! If you're in one of those countries, can you confirm? The sponsor is 80,000 Hours: head to 80000hours.org/steve to start planning a career that is meaningful, fulfilling, and helps solve one of the world’s most pressing problems.
Zelphi Zorous
how did you do that? im in us and it says gas
Arca Ege Cengiz
It says petrol in the UK
CMT Crabbles
CMT Crabbles 年 前
American here, it does show as “gas” Thats really cool!
Brad 年 前
Gas for America
Alex Watt
Alex Watt 年 前
Petrol in uk. 🎉
Worlds Okayest Engineer
I’m a an engineer and I used to work for the company that originally created that design. Actually, I redesigned that ball bearing mechanism. I can confirm that you are correct in your assessment of how it works. Also, most gas nozzles have a second diaphragm or plunger (not membrane) that deflects when there is pressure in the fuel line. It is used for prepay fill up. When you hit the prepay amount the dispenser shuts off, the pressure in the nozzle drops and that second diaphragm which is spring biased up will move and shut the nozzle off. There is a third shutoff in some nozzles that is called an attitude device. When a … moron… pulls a flowing nozzle out of a car’s fill pipe, a ball bearing blocks the pickup tube and shuts the nozzle off.
Ritesh Dhakate
Ritesh Dhakate 6 ヶ月 前
Please make a video about that too :P It's quite difficult to understand how prepay is hit and what happens when a moron pulls out a flowing nozzle out of the car.
Sleepy Joe Scumbag
Sleepy Joe Scumbag 6 ヶ月 前
Cool story Mr "I am an Engineer"
CZRaS 6 ヶ月 前
I'm the bearing and I can confirm this is a lie
Black Mesa
Black Mesa 6 ヶ月 前
Anti-moron mechanism lol
Adithya V Raajkumar
Adithya V Raajkumar 6 ヶ月 前
Regarding the attitude device, what if I want to fill up a spare container of gasoline or something like that? Wouldn't the 'attitude' device prevent me from doing so?
BigMilk13 10 ヶ月 前
Many youtubers wouldn't have taken the time to craft the supplementary models that you made for this explanation, but I am SO GLAD you did. I'm a big visual learner and those models were excellent (and I can tell you had fun making them as well).Thanks for answering yet another question I didn't know I had!
Rohan Sanjith👑
Rohan Sanjith👑 5 ヶ月 前
Because many youtubers don't get millions of views like this channel, and it'll be a waste of effort
Jose Lopez
Jose Lopez 3 ヶ月 前
Every heard of practical engineering? He also loves making mini models
Excellent explanation. It was worth the effort you put into that illustration. Thanks to that I have understood perfectly how something that I always ask myself works. You have made all of that seem so easy now, and it really is, but to most of us it seems more complex than reality. Thanks and greetings from Tampa, Florida.
Trevor Carlisle
Trevor Carlisle 7 ヶ月 前
I know! I was thinking "wow, I actually understand this model that he made."😂 Give him much props for that 👌
Kimberley Sanchez
Kimberley Sanchez 7 ヶ月 前
I totally agree. I'm so impressed that he built the models & presented the effect so clearly. Very interesting - I'm a fan now.
M 9 ヶ月 前
Pretty complex mechanism. I always thought it's somewhat simplier. Very good vid Steve.
Glum Reaper
Glum Reaper 8 ヶ月 前
Its very simple mechanically if you think of the two parts as a sensor and a signal not to mention whatever it takes to close the valve. These gas pumps basically take a three part problem and use two mechanisms to solve all three. The beauty of the design is that both operate with only fluid dynamics. Most other sensors require a bit of chemistry or some other physical property (to detect a chemical presence) and a bit of electricity (to transmit the signal) as well as moving parts to operate the valve.
Lord Zordid
Lord Zordid 8 ヶ月 前
@Glum Reaper If it was so simple, in the old days they would have used the system to fill up their horses.
The Muckler
The Muckler 7 ヶ月 前
It is simple. Basic pipe fitter knowledge
Jaylectrick 4 ヶ月 前
@Lord Zordid i tell ya son in the ol days we filled arr horses witha notha type of pipe and we damn well knew when to stop
Adrian Gigante
Adrian Gigante 10 ヶ月 前
As a sales engineer I find it amazing how you drive us through the explanation and build up the complexity of it. I'm learning more than just how gas pumps work!
Allen Zhu
Allen Zhu 9 ヶ月 前
As a chemical engineer, it is a very great demonstration and it’s fascinating how in depth you went with the Bernoulli effect, great work!
Robert Smith
Robert Smith 年 前
This is one invention that never seems to fail. It's never failed for me and I'm 66 years old. I've never seen or heard of this valve not working from other people either. That's quite a successful bit of engineering, I'd say.
aapddd 11 ヶ月 前
Physics works.
Gary 11 ヶ月 前
I've found (accidentally) that it is possible to make the valve fail, at least on some pumps, if you are only partially pulling the trigger (so that the flow is reduced). Specifically, I was watching the meter (instead of the nozzle), trying to put in a "round number" amount of fuel, without realizing that it was just slowly overflowing onto the ground! I'd guess that the reduced flow-rate also reduces the "negative" pressure on the diaphragm, such that it can't overcome the spring force (to then shut off the fuel).
Casey M
Casey M 11 ヶ月 前
Oh it fails. Never fully trust it
CallioNyx 11 ヶ月 前
I agree, Robert. It's a very clever bit of engineering going into those things.
IchEben 11 ヶ月 前
Lucky you. It faild 4 times on me till now and I'm only 33. One time spilling all the gas and Three times stopping multiple times bevor the tank was full.
Kit 8 ヶ月 前
Your vids help me learn physics in a way my college classes couldn't. Even though this was a lot to follow and kind of hard, it all clicked in the end and I feel so excited to know how this system works 😊
A Nonim
A Nonim 9 ヶ月 前
Great video. What I like about this mechanism is how non-electric this is. You have to admire engineers that developed that back in the days. Nowadays I got impression everything needs to be computer controlled. This mechanism shows us what true engineering is and it is uncanny.
Joeshinhwa 123
Joeshinhwa 123 5 ヶ月 前
It has to be non electric. If there is anything electric in that nozzle, well, electricity+gas= trouble. 😅
First Name Last Name
right. to me, automatic watches still blow my mind. true engineering
durlav dhadumia
durlav dhadumia 8 ヶ月 前
Thank you for explaining this! These old mechanical techniques of automation are fascinating!
Richard Aversa
Richard Aversa 8 ヶ月 前
The mechanism is both elegant yet high complex, and understandable thanks to all the detail and props Steve included. Well done!
beppebergmanable 8 ヶ月 前
My parents ran a gas station and I helped them since I was a child. Your explaination helped me understand a phenomenon I experienced many times in my first twenty years of life! Very ingenious, hope someone was rewarded for this mechanism. Nice video and very good explaination, thanks!
Andrew 15
Andrew 15 2 ヶ月 前
someone was rewarded... by a paycheck... so dont worry!
Donald Sayers
As a (retired) technology teacher, I can respect the huge investment in time and energy needed to make and test those models. Also your perspex models are getting better as you learn. Good jobs all round.
Like what Edward R. Murrow said about television except put in the hands of people who care about such things- "This instrument can teach, it can illuminate; yes, and even it can inspire. But it can do so only to the extent that humans are determined to use it to those ends."
Adi 年 前
you must have been amazing teacher
ColaKnugen 年 前
@Adi i get the same energy
Beast 11 ヶ月 前
And the money he makes on youtube.
veryslyfox 10 ヶ月 前
It's amazing how clever the guys were who invented these things. Wonder when a woman will ever invent something like this
PlanB 8 ヶ月 前
Considering how many modules he made just to explain his discovery, this guy is qualified to be teaching in Physics class. Impressive work and welldone Steve.
SgtKOnyx 3 ヶ月 前
The "sword" and circles you used at about 8:30 is interesting to me, as it's a roller locking mechanism, which is used in some firearm designs, like the MP5 or G3, though in the MP5 it's not actually locked but "delayed" by this mechanism.
Grant Pray
Grant Pray 10 ヶ月 前
Holy cow, that was an amazing video explaining all the different pressure effects and illustrating it with amazing models. I always love your channel, but I just wanted to say this one was pretty cool!! Great job on the effort!
I do love a well designed mechanical solution. thanks for taking the time to explain this. I thought it was something related to pressure and valves, but never imagined the system was this complex.
FourthLittlePiggie 8 ヶ月 前
Great video with very good illustrations and descriptions. I always had some idea of how I thought it worked (I assumed some sort of cam and/or clutch mechanism paired with some kind of air pressure sensitive system) and it was nice to finally understand. Thank you for the explanation.
iTrialpha 年 前
You can feel the petrol (water) hammer/hydraulic shock when the pump shuts off as the valve closes as well. Always wondered about that, cheers Steve this was really interesting
Steve Mould
Steve Mould 年 前
Oh yeah! Good observation
Matt H
Matt H 年 前
Yea, and see the whole hose jump from that effect.
Kevin White
Kevin White 年 前
@Steve Mould From your demonstration, it also seems like when the gas valve gets closed, the fluid flow is now pushing the valve shut (it was held open by the lever action), which probably contributes to it slamming shut. Which I presume is also good at ensuring that the gas flow stops immediately. I bet if you had made your plastic cutaway demonstrator with a much larger diaphragm, it would have moved a lot further. Since there's no such thing as negative pressure as you said, the diaphragm moves because outside air pressure pushes on it since there is lower pressure pushing back on the other side. That's how the power brakes in a car work - they aren't being actively pressurized (except maybe when your ABS gets triggered), and instead a vacuum from the intake manifold of your car engine is formed on one side of diaphragm that can be up to 11" wide. That's 95 square inches, for a maximum sea level force of 1,425 pounds, and that is multiplied through the master cylinder like with the pedal leverage. Thus even a partial vacuum in your power brake booster has force comparable to how much you can press down on the brake pedal with all your might.
Agustin Campeny
What is the mechanism that triggers the shut off when flow is stopped at the pump? I cannot see it clearly.
Mungo 年 前
@Agustin Campeny It could be a simple pressure sensor somewhere in the whole tube system. It also depends on the pump used - it can be simply running all the time you take the nozzle assembly out of the main body till you return it - some pumps have no problem to pump the liquid against the closed system - in that case you need no sensor just the one that checks if the nozzle assembly was returned back
K Jamison
K Jamison 4 ヶ月 前
Taking the time to create the demonstration models really helped to nail this! Your delivery was pitched just right without resorting to dumbing down the content. Thank you!
helmet098 10 ヶ月 前
This is fascinating. I think a part 2 would be interesting showing how they activate and deactivate the pumps
YoshMaster 8 ヶ月 前
All my life I’ve spent half of my time at the pump wondering how this worked!! Thanks for finally letting me know 😁
vonschlesien 9 ヶ月 前
That mechanism with ball bearings is very reminiscent of a roller-locked automatic firearm - rollers on the bolt stay pushed out and jammed into the frame (receiver) until the pressure in the chamber drops and it's safe for the action to open and cycle.
Gordon McKnight
I remember looking up how this worked a few years back. The fluid dynamics and drawings went way over my head and I was left confused. Incredibly impressed (but not surprised) that you managed to clearly explain the mechanism to a total lay person in just over ten minutes!
Micah Philson
I've been going through an engineering course over the last couple years, and I've learned a ton about fluid physics and dynamics. This video covered so much of those classes all at once and explained it all so clearly and succinctly, such in-depth topics so concisely, he makes it look easy! This video is incredibly well done!
Burnt Alive
Burnt Alive 年 前
I read a youtube comment about it a couple days ago and didnt really understand it. The visual explanations really helped it click all together!
Analog Dude
Analog Dude 11 ヶ月 前
@Micah Philson because "highly" educated people think to complex, i follow a professor here on tube, it's pretty much theory, but no practical experience and rather clumpy. they have a star mind, not really open for new things and ideas, than someone without a university degree comes along and leaves the professor stunned and in the dust. you shouldn't really admire these people, they aren't really smart al better at numbers because of routine. they can't solve simple things.
Micah Philson
Micah Philson 11 ヶ月 前
@Analog Dude I'm in a military training program, we're only learning about the systems and the theory behind the systems we use, and working practically with those systems. We're taught by people with like at least 6+ years of experience, not professors. But to do it, we have to learn all the theory and physics, chemistry, materials science, fluid dynamics, engineering etc. behind it all because it's literally nuclear physics and nuclear power.
Analog Dude
Analog Dude 11 ヶ月 前
@Micah Philson waste of time, people that see ghost where there aren't, better the invent something on your own and hope that it sells. they asked me as well when i was 18 and i told them you must be joking, you must be out of your mind and they left me alone, recently i got to speak to one of these people, lol.
Jao Jester
Jao Jester 10 ヶ月 前
Thanks for taking the time and puting the effort into explaining such a complex and smart design in simple to understand concepts, along with all the visuals to make it easy to understand. I always enjoy learning new things and I really enjoyed that one. Thanks!
Nik 7 ヶ月 前
Always wondered how these worked. It's an astonishingly reliable mechanism. Having worked in a fuel station I have seen them fail to stop on occasion. mostly in the winter months.
Zara Poeta
Zara Poeta 6 ヶ月 前
Wow, I guess that's why ytube is so popular. Dude you have put an insanely amount time into making this vid I really, really enjoyed this, thank you for taking up your time. As engineer it was quite enjoyable to see Bernoulli Venturi in action in such a device I never thought this nozzel was such a "master piece" of a design. Thanks a again and keep the hard work!
Bytor Snowdog
Bytor Snowdog 4 ヶ月 前
Excellent job Steve! I had a vague understanding that a Venturi principal was at work here, but never understood how the then nozzle would shut off then reset. Well done!
Naman Sinha
Naman Sinha 4 ヶ月 前
I studied various concepts such as these during my JEE preparation and even though I didn't clear the exam. I feel proud that I have the basic introduction to concepts like these.
Roman Michael Hamilton
I was mentored by the two engineers who patented this back in 1965 and worked with them for over three years. They are both gone now, but they gave me a lot of knowledge during that time. One was like a second father to me and he was as detailed and meticulous as one could be. They two men didn't get much out it as like most corporations do, the board takes it all for themselves.
João Gabriel Paina
João Gabriel Paina 10 ヶ月 前
That's how our system works. If You have a really good idea that will generate millions or maybe billions a small group takes basically all the money at the same time you receive almost nothing. Even more, some of them will say that if you are not rich it's because you are not trying enough (when in the first place all of your work is their source of richness).
RA 10 ヶ月 前
fascinating to find those with near 0-degree connections to things like this. Have you any stories from the 2 engineers you're keen to share?
Osono 10 ヶ月 前
Why not mention their names?
Mister E
Mister E 10 ヶ月 前
@João Gabriel Paina that's because the world is far more complicated than just having a really good idea. Marketing, logistics, accounting, managerial skills are all critical to turning a good idea into a gold standard. I'm not saying we can't make improvements, but the skills to take a product to market are just as important as having the idea for the product to begin with.
João Gabriel Paina
João Gabriel Paina 10 ヶ月 前
@Mister E Well, you are completely right. Even blue-collar workers play an essential part in that system. Without the guy soldering, machining and so on your idea is just an idea. My point on that is to have everyone that works to run the business then share the profits. The billionaire who runs the business is nothing without the marketing, engineering, logistics, e so-on team. If the class of workers (and by worker I mean those who depend on salary) begins to understand that everything that exists around it depends on them, the few billionaires that explore their workforce are done.
Mohammed Waheed
Mohammed Waheed 8 ヶ月 前
Amazing! Always wanted to know how it works. I knew it wasn't something electronic as this mechanism was accessible to us in Iraq after the gulf war, so I knew it must be pretty old technology. It is fascinating how innovative people and product designers used to be back in the day!
Burt Vincent
Burt Vincent 6 ヶ月 前
You did a good job. A layman explaining principals of hydraulics with no engineering experience in the field is challenging for sure.
midnight-matches 8 ヶ月 前
Kudos to the incredible engineers who made this all possible that we now take for granted.
Funnyvid16 10 ヶ月 前
I use to work at a gas/petrol station, and the amount of times people who don’t put the nozzle spill gas that blame the pump is astounding. I wish I could just play this video to show why it’s their fault back then, wonderful video!
Onii 5 ヶ月 前
Oh nice, I was always worried about overfilling my tank for some reason and it's good to learn how this stuff actually works to alleviate those worries
Frank Mayer
Frank Mayer 年 前
I am fascinated by how much simple technologies are put together inside that thing and how hard it is to explain how they interfere with each other…
Stefano Palmiotto
Stefano Palmiotto 11 ヶ月 前
Cause theoretically they’re not simple, the fluid mechanics behind them is quite fascinating
Bob 11 ヶ月 前
Some people can explain in 2 minutes what others take 2 hours to do.
Caderic 11 ヶ月 前
Well, it is multiple simple devices put together to make a somewhat complex device.
Dylan Kruse
Dylan Kruse 10 ヶ月 前
Now I know how they work. Love your explanation and how you teach. Keep up the good work!
Colonelloki 10 ヶ月 前
I’m an ME and I had a vague idea and knew it was based on the Venturi effect but I never knew how it used that to shut it it off. The ball bearing mechanism shifting the pivot point is a brilliant way to solve the problem.
TwistedCream 7 ヶ月 前
Steve Mould, This was very helpful thank you. I now understand why gas may not come through during hot weather. Gas expands with rising heat, and understanding how this nozzle works is enough to see why the expansion of the gas would make it much more difficult at times in high heat areas with certain types of nozzles.
Lee Chetwynd
Lee Chetwynd 8 ヶ月 前
Thanks for explaining something that I briefly wonder about when filling up, and then forget about when I drive off. Now I will always know what happens!
GCEism 8 ヶ月 前
Thanks for this fantastic explanation! I used to work at a petrol station for 3 years and always wondered what was happening. Especially since we used to fill for the customers and on some occasions the pump would either constantly switch off despite not being full or fail and continue to overflow. It was never the pump itself as it would only happen with the single customer but now I'm wondering how the shape of the tank or angle of entry would affect it. I now know when people pulled up with the tank on the wrong side and we would have to stretch it around and have it pour from a 90° angle, why it would tend to overfill. You begin to learn the sound of when it's almost full out of repetition.
NoTimeLeft 年 前
The fact that you made a see-through, 2D version makes me unbelievably happy! Well done good sir
Peter Knutsen
Steve always makes see-through 2D versions!
Andreas Gurdel
Luckily this is not Matt Parkers channel. His stuff is great too, but he would make a 4D version that clarifies nothing.
Nilguiri 年 前
@Andreas Gurdel haha, excellent comment!
Gharelu Musician
Gharelu Musician 10 ヶ月 前
What a genius and brilliant solution the humans came up with ! I always wondered how it shuts off automatically when the Gas tank is full. Thanks Steve for this video. ❤
Tex Murphy
Tex Murphy 10 ヶ月 前
Schools should show your videos - we could easily double the number of kids entering STEM related fields by watching your educational videos that explain how two “simple” concepts in Physics can be used to keep gas from spilling onto my feet! Great Job!
numbr17 9 ヶ月 前
Fascinating video! I love the way you explain this, and the mock ups you used. Really nice work! Thank you for sharing this. I've always wondered how they work.
Kryto 7 ヶ月 前
Now that was interesting. It seems like the workings are way more complicated then I thought. I wonder how difficult it was to invent such a device that we all take for granted today.
32Omicron32 9 ヶ月 前
Thank you. A wonderful explanation for a mechanism/physical property that not many have seen in everyday life. That showed how the tank being full stops the pump but on some pumps the stopping of the flow of gas/petrol from the pump also triggers the fulcrum release. How does that happen, since at that point there is no pressure differential from the fuel flowing?
Glum Reaper
Glum Reaper 8 ヶ月 前
That might be a mechanism with the modern electronics of prepay pumps. The gas station assumes you turning off the flow means you've finished your purchase, so their pumps probably have an electronic override when the flow stops. It's likely electronic since that override only gets disabled by the computer sending a signal to the pump to turn on after you've paid. If you've used a very old not prepaid pump, they don't have to be reset to continue the flow after being tripped (but they will still stop if they're experiencing a venturi siphon against a full tank).
Gina Miller
Gina Miller 5 ヶ月 前
As long as I can remember, I have always wondered how these things knew when to shut off! Thank you for an excellent explanation !!
Scorpion Green
I love these kinds of (fluid)mechanical solutions to problems. They always seem so intricate, but built off such simple elements. Great design, great video!
Ivan Novikov
Ivan Novikov 年 前
And so robust , too!
bmac2368 25 日 前
That was an amazing explanation, I don’t think it could have been better! Nice work!!!
Lucas da Matta
Lucas da Matta 8 ヶ月 前
that mightve been one of the most interesting youtube videos i've ever seen and believe me i've watched a lot. spectacular job at coming up with the models to explain the mechanisms. thank you!
XtalShrimp 7 ヶ月 前
Steve; I've got to say, when I saw all your models and the title of the video I was confused on how any of it made sense! But the way you explain it all makes everything fall into place, it's very impressive!
BilleteraMataGalán 6 ヶ月 前
Este invento es una genialidad que pasa inadvertida a diario. Gracias por esta excelente explicación. Has ganado un suscriptor más 👏🏆
Chris Gargasz
Chris Gargasz 8 ヶ月 前
Very cool. You know I’ve never actually wondered how they work. Then I saw this video and I was intrigued. Thank you. Gas pumps are much more complex than I thought.
Scott Carr
Scott Carr 年 前
*Standing Ovation* This was an incredibly thorough and intuitive explanation. Thank you Steve!
Jacob Shirley
Welcome to the channel!
Avez610 年 前
GuyJustCool 年 前
If somebody could understand and explain quantum physics, it’s this man. Thanks, Steve, amazing, as always.
Jacob Shirley
@GuyJustCool For those topics, I think ScienceClic does the best job one could possibly do.
Rose Brigade
Rose Brigade 5 ヶ月 前
Clever little mechanic that is. I actually had an idea it was something like that but not to that complexity. I was just thinking if the gasoline feeds back into the system or reaches the nozzle it just creates a reverse pressure or something like that. But having this demonstrated right here actually makes full sense. Well done explaining.~
He-Who 10 ヶ月 前
I took one of these apart once in my auto tech class while I was bored (I had to wait for the rest of the class to catch up) but I couldn’t figure out how it stopped like that. Thanks for the explanation!
Pedro Câmara
Pedro Câmara 6 ヶ月 前
It would be interesting to see an interview with someone from GoW's team to hear from them what is this job (and how this somewhat big team of designers worked together to make the "sugar").
Eduardo Zocchi
Eduardo Zocchi 5 ヶ月 前
WONDERFUL!!! I spent all my life wondering HOW IN THE HELL this stuff works!!! But thanks for this absolutely magnificent explanation, I finally got all the deep secrets and science hidden behind this nozzle!!! And it's amazing the big amount of work Steve had to assemble all of those devices! Thanks, Steve, you're a great man! 👋👋👋👋👋👋👋
Peter Harris
Peter Harris 9 ヶ月 前
Wow that is extremely complex! Love the level of genius that goes into everyday objects
Ernest 11 ヶ月 前
The fact that this is all done mechanically and not electronically is what makes this so cool to me
gordon onkyo
gordon onkyo 10 ヶ月 前
Many principles that would function forever with repair that a craftsman can do will be replaced by digital stuff that needs from now on monetarized upgrades from above. That's cool for the big players.
Reasoner Enlightened
Reasoner Enlightened 10 ヶ月 前
can it make the fuel free?
Max_Power 8 ヶ月 前
Want your mind blown? Look for videos on mechanical targeting computers.
Shaun Young
Shaun Young 7 ヶ月 前
I wouldn't be surprised if there are electronic components to some these days or in the near future. But these automatic shutoffs long predate the cheap and widely available integrated circuits we have today to enable us to computerize everything. These cutoffs were used before electronic displays became common. /I had always assumed it was based on a float, though
Organic Farm
Organic Farm 6 ヶ月 前
yes, when most of the technology is becoming less mechanical more electrical, this piece of tech remains the same;)
holohulolo 8 ヶ月 前
I have been wondering about this since I was a kid and over the years I also assumed it was an electrical sensor. I never wouldve imagined it's mechanical.
Robert Lee
Robert Lee 8 ヶ月 前
where is the wire hidden/
B Babbich
B Babbich 4 ヶ月 前
Sensors need to be replaced once they break. Thats why stuff like this should always be achieved mechanically if possible. Practical application for stuff like this is always mechanical.
hauntedsunsets 8 ヶ月 前
as someone who's never filled a car with gas once in my life (driving gives me insane anxiety so I just bus everywhere) I never actually considered that these must have a way to stop themselves. glad they do
Jairo Morales Martín
Explicación brillante. Siempre me pregunté cómo funcionaría 👏🏼
From Gaming with Love
From Gaming with Love 10 ヶ月 前
13 minutes ago I was more confident I could build a fusion reactor out of gummy bears and duct tape than understand this mechanism. Even at the halfway mark I was a bit lost but man- you fricken nailed it! Thank you!
Raven Bailey
Raven Bailey 10 ヶ月 前
I’m so confused how would you do that😂🧐
Aaron Andino
Aaron Andino 8 ヶ月 前
Fantastic video. Always wondered this. Love seeing the engineering behind this.
Richard Stewart
Richard Stewart 10 ヶ月 前
I have worked as a mechanic and as an electrician for most of my adult life. Part of the fun of these careers is trying to figure out how things work. Most are pretty easy, however, I can remember a few times while pumping gas into my car that I thought about how those nozels worked. I thought a ventury and valve might have been involved, but never was able to tie it all together. Thank you for clearing all that up...Its always nice to see how things work. Well done!
Danny Archer
Danny Archer 10 ヶ月 前
Part of the fun? I never open anything up to figure out how they work because of the anxiety it causes me knowing that I am invariably going to break something or not be able to figure out how to put it back together.
Tim N
Tim N 10 ヶ月 前
nozzle, venturi. and yes, it does matter.
Corintur 10 ヶ月 前
@Danny Archer That is why you only do that with stuff you don't really care about or that is already broken. I never throw any device away before performing an "autopsy" on it. Though, I would still advise doing some research before dismantling something. Knowing about compressed springs, dangerous capacitors or possible toxic substances in certain components can save you a lot of pain. Besides, this is YT and it has its own version of Rule 34. If it exists, there is a video YT video of someone dismantling it.
Richard Stewart
Richard Stewart 10 ヶ月 前
@Corintur Back when I was a kid in the 50's and 60's I used to drive my parents nuts because I took just about everything apart and tried to but it back together. I succeeded most of the time, but there were a couple of times I made things a lot worse. We didnt have youtube back then and the stuff in the libraries was vague at best. I grew up trying to fix everything I owned and never threw anything away. As to compressed springs and stuff like that, I had a couple go flying across the room, but you learn to be careful over time. And yeah, I now have a ton of junk stacked in my garage from all the fixin, but now, I can call them all antiques and sell em on ebay!
Nostalgic Bliss
Nostalgic Bliss 10 ヶ月 前
@Danny Archer That's why you're not an engineer
Z 7 ヶ月 前
Thank you for explaining this and showing a cross section. I don't own a car so I have no idea how these things work and every time someone asks me to help them with filling their gas I always pull the pump out at the wrong time cover myself in petrol. Just knowing how much the nozzle holds will help me a lot
Uncletaco supreme
Uncletaco supreme 2 ヶ月 前
Your filler neck also has a vent tube that runs parallel to it, and allows the gas to pass freely through the tube without backing up. If you find that the pump continues to click off without filling your tank, you need to have the vent tube cleaned out or maybe replaced. I love your videos.
Dave Cooper
Dave Cooper 8 ヶ月 前
Once upon a time you could clip the pump open. The idea was that the nozzle would automatically click off once the tank filled. Occasionally someone would walk away leaving to pump to cut out on its own. Meaning that there was a potential for the pump to run on even after the tank became full.
Petter Bruland
Petter Bruland 10 ヶ月 前
What a wonderful video. Just had a conversation with my kid about this, after he had seen some accidents where "un-smart" people spay gas/petrol all over the place. They probably did not insert the nozzle correctly, my educated guess after watching this video. Thank you Steve!
6 Feet South
6 Feet South 10 ヶ月 前
I am no engineer, technician or mechanic, but I have been taking things apart all my life to figure out how they work. Thank you for explaining it all so well.
Max A
Max A 10 ヶ月 前
Did u put them back together afterwards?
DSG Sleazy
DSG Sleazy 10 ヶ月 前
@Max A he didn't say he was a puter back togetherer.
AntA Survival
AntA Survival 8 ヶ月 前
I like to take things apart. But, when i try to put it back together, i always get some extra screws.
GenericHandle01 7 ヶ月 前
I truly wish Applied Sciences had been a constant class in my schooling education and that you had designed the curriculum. 1: Studying how things work promotes more avenues of creative and critical thinking, so I believe the more people who understand the principles of how things work, the more innovation we will have. 2: When I have children I want to teach them what they need to know and what I would like them to know using Applied Science as the foundation for their education.
lpdog82 10 ヶ月 前
very good info indeed, i always wondered how the gas nozzle cut itself off, thanks for showing me this! , amazing engineering went into a nozzle like this , smart inventors out there!
Craig A. Smith
Craig A. Smith 10 ヶ月 前
I've been using a small low pressure automotive fuel pump to transfer fuel between tanks for years. I've often wondered if adding a gas pump handle would work for keeping my transfers from overflowing, which they do when I become inattentive for a split second. Clearly my pump doesn't have the pressure / throughput to operate the mechanism in the handle. Thank you for explaining why.
KO 6 ヶ月 前
Okay! Finally, after 55 years of staring at the pump nozzle while I pumped gas and thinking how it does that, now I know. I always figured it had something to do with pressure variables but that's all. Thanks for the video.
SkitScape 7 ヶ月 前
This video actually answered another question I've always had about these pumps; which is why the heck is there always so much that drips out after it shuts off. Now i see how large that chamber is between the initial valve and the nozzle. You're gonna see me at the pumps turning that sucker all the way upside down to drain out from now on.
MrEcted 11 ヶ月 前
This is one of those things I've probably wondered about 100 times while pumping gas, but always forget about by the time I get home so I never looked it up. I'm glad you have finally answered this mini-mystery, and done such in a way that is intuitive and easy to understand! I always assumed it was probably some sort of electronic sensor, but this is far more clever!
Madhukar Jonathan Minj
i recently started driving,infact got my license on 14th of this month,and wondered about this question only a few days back.
TIMEtoRIDE900 11 ヶ月 前
I thought the European model would be much smaller considering they are pumping Liters and not Gallons.
Herra Käärme
Herra Käärme 11 ヶ月 前
@TIMEtoRIDE900 Maybe the pressure (flow) is just much higher in the USA? So that it takes the same time for a European to fill up the 40 liters tank of a shoe-sized Fiat Punto and for an American to fill up the 40 gallons tank of a Ram TRX monster.
jabcam 11 ヶ月 前
Haha! Me too! And my work mate also. We discussed this just the other week. So now, rest at last.
TIMEtoRIDE900 11 ヶ月 前
@Herra Käärme It varies between gas stations (USA) sometimes you get a slow pump, very rarely you get a REALLY fast pump, and if you pay inside the last gallon delivered goes SOOOO slow! like they don't want to give you an extra penny's worth. When I fill my boat it doesn't "trip" the shut-off so I have to listen for a slight gurgling and shut off myself or it spills several OZ on the swim deck. It's because the filler tube is 2 1/2" (60mm).
Evan F
Evan F 10 ヶ月 前
Great video! Now understand how it’s supposed to work but I’m still curious about what’s going on when it doesn’t? My old truck had a habit of the gas flow shutting off well before it was full unless I was very careful to reduce the rate of flow from the nozzle, and I know someone who at least once has had gas come pouring out anyways- it never shut off for them. Any idea why these might have happened?
queenannsrevenge100 10 ヶ月 前
It’s awesome to see the ingenuity of mechanisms like this - physics is more reliable than an electric sensor, so when you have something as a safety mechanism, better to rely on principles of physics.
Atbi Aol
Atbi Aol 2 ヶ月 前
Amount of effort you put in to explain this, is incredible
Richard Menezes
Richard Menezes 10 ヶ月 前
absolutely brilliant, not just the mechanism, but your explanation as well, thank you
Tanmay Suryawanshi
Tanmay Suryawanshi 7 ヶ月 前
I was always curious on these pump nozzles, thanks for fulfilling my curiosity and such a good explanation
wojtekpolska 11 ヶ月 前
You have a great style of making these videos. 1 - You really struck gold with these 2D models, they show everything so nicely and without clutter 2 - You explain things in multiple different ways, which is helpful when someone doesn't get it the first time, and then would be confused for the rest of the video So thanks for showing off clever designs and physic principles in this way :D
Nour Art
Nour Art 5 ヶ月 前
I would never have thought this is how they work, this is actually genius
Colin Atkinson
Colin Atkinson 6 ヶ月 前
I had no idea how it worked. I thought some kind of sensor did it. You have provided an excellent explanation of a complex device that we all just take for granted. Is there an automatic sort of ' flash arrester ' that are fitted in gas cylinder valves ? Or is there no requirement ? Thanks for the video.
Sean Not-telling
Sean Not-telling 8 ヶ月 前
Hi, Thanks for the explanation on how the delivery nozzle does the auto shutoff. I had a good idea how it worked. Seeing it makes it a lot easy to get one's mind around it.
Michael H
Michael H 4 ヶ月 前
I worked at a gas station in high school. There's also a shut off for when people drive away with the nozzle still in their tank (which happens a lot).
Eric 8 ヶ月 前
That plug on a spring that forms the Venturi is also important. It clenches the size of the Venturi so that you get good vacuum regardless of flow. Well, not regardless but slow flows will still trip it.
Thoron Neto
Thoron Neto 年 前
I tell you, if my professors had been as dedicated to explaining the venturi effect as you did in this video, I'd probably have picked up on a significant amount of the things they were teaching me. A lot of how aircraft work, is based around the venturi effect and the bernoulli principle because the one thing aircraft have in abundance, is air moving rapidly in a single direction lol.
Julian Brelsford
Yes, the principles discussed here affect the functioning of wings, pitot tubes, traditional "six pack" instruments, etc
Thoron Neto
Thoron Neto 年 前
@Julian Brelsford yep, and the applications only scale up the bigger the plane gets! I have disassembled something so many times and found a venturi of some flavor or another so many times!
Mateusz Obara
My fluid mechanics professor would kill me though if I were to tell that Bernoulli principle can be explained by conservation of energy (such explanation is limited and works only in some specific cases)
cr01 年 前
Venturi effect is how carburettors work, too.
Cookiez __
Cookiez __ 年 前
@Julian Brelsford Unfortunately wings do not fly because of bernoulli's principle (and as such the venturi effect), its a misconception.
hifasiga209 10 ヶ月 前
This was a great explanation. However I'm very curious about what causes that to happen when the gas tank is not full. With some cars including mine I'm not able to fill gas because it just shuts off immediately as I press and leave the lever. There's a workaround of tilting the nozzle about 90 degrees from the downright normal position. Sometimes I have to just barely press enough for the fuel to come out for it to work. From the explanation I feel that means the something is blocking airing from getting through the venturi port on the bottom that you mention? But how can that happened if the tank is only a quarter full? Splashing? Or some emissions tech preventing me from pumping?
Mark Pentler
Mark Pentler 10 ヶ月 前
Have you seen the "Open Circuits" book yet, Steve? Lots of electrical components cut in half so you can see them on a physical scale and how clever lots of them are. (like switches etc)
Moshe Delerb
Moshe Delerb 8 ヶ月 前
Kudos on all the effort you put into making this video!
Himneesh Chowdhary
Himneesh Chowdhary 7 ヶ月 前
recently studied the venturimeter in high school. It's a hard concept and i thought why is this being tought? well, this video not only showed me the application, but also cleared my concept even further.
Joshuya Raidon
Joshuya Raidon 6 ヶ月 前
I'm guessing the venturi effect only works if enough gas is flowing through the nozzle. Once it stops, if I let go and squeeze on the trigger like normal again to restart it, it'll stop again pretty quickly. However, if I reduce the squeeze on the trigger to have the gas flow out more slowly, it doesn't stop itself. It's what I've noticed whenever I want to round up the monetary amount.
Cadell Teng
Cadell Teng 年 前
I respect the tremendous amount of time and effort you put in to the making of visual tools that you use to explain. There were at least 2 glass tubes, that green and red pipe stuff, the sawn in half nozzle, that mock up of the sawn in half nozzle and possibly more. Yet somehow, all I could do was to like, sub and share your video to my social media. I few that what I do isn't proportional to the amount of work you put in to this video and that is why I have mad respect for you. I thought I was a huge nerd, but I think I found a bigger one in you.
Brian Merritt
I wouldn't worry too much, he's getting paid hundreds of thousands from JPvid for all the views he's getting from these videos. It's a full time job that pays very well.
h8GWBî 年 前
@Brian Merritt It might be lucrative, but that doesn't negate the amount of the effort that went into the video. Sometimes the ability for a JPvidr to turn their videos into a career is at the whim of the mysterious algorithm.
Synth Apprentice (Nathan V)
@Brian Merritt No, he's really not getting nearly as much money from JPvid as you think he is. He's almost certainly getting most of the money for this video through Patreon. Most JPvid users don't realize this, but JPvidrs need to have several sources of income (JPvid, Patreon, sponsors, merch, etc) because no one single source will provide enough money on its own.
Synth Apprentice (Nathan V)
If you really want to do more to support the channel, consider contributing as a patron on Patreon.
Leonardo Cavalieri
Leonardo Cavalieri 4 ヶ月 前
This was extremely interesting, it's such a clever mechanism. I also thought there had to be some electronic sensor, so thanks for clarifying it
시계토끼 White Rabbit
This is simply genius! Thanks for explaining it in details.
Liam Draper
Liam Draper 8 ヶ月 前
I always thought it was somehow related to a loft water tanker, where once the float is floating so high on the water it’s lever blocks the incoming supply of water
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