Absolute perfect description of a pilot-operated valve (for either pneumatic or hydraulic). I work with solenoid valves, pressure regulators and pneumatic relays on a daily basis, and you nailed it with a very easy to understand theory of operation regarding pressure differential on either side of a diaphragm.

Now i finally really understand how this works. Thank you very much !!!

Cool, thanks Clive. Been looking at these (among other solutions) for an auto watering setup for a friends allotment. Nice to see inside of one before deciding.

Spot on with spring! Its purpose is to clean the compensating port and it's patented by the company I happen to work for :-) Btw. very nice explanation of the servo mechanism!

I remember Tim Hunkin explaining this incredibly clever device on The Secret Life of Machines circa 1986. I had in fact forgotten about the actual design of the diaphragm so this has been a nice revision session for me. Thanks a lot

Very interesting and a nice explanation of how it works. Thanks

Thanks, Clive. I always enjoy your videos and find them to be fun and educational.

Enjoyable and revealing vid again Clive! I actually have an interest and book marked a few of these in my Ebay 'watch list'. My friend who has finished (unlike me) his van/motorhome conversion, uses one of these to remotely dump his 'grey' water tank which, I thought was a very cunning idea! Thanks for the education of its internals!

Modern toilet cisterns have fill valves which work with the same method - it means the float can be much smaller as the force required is less than a traditional ballcock and valve assembly which equates to smaller, neater cisterns.

Wired up so many of these solenoids, now i know how they work. cheers!

Simple and clever engineering, thanks big Clive

I hooked up one of these to a momentary switch on my Keurig to refill the water reservoir. It works great, but you are correct that it has a small delay to stop the flow.

Your discussion and drawing were very elucidating, many thanks Clive. I construct irrigation systems but haven't yet had need to service a valve interior, and so wasn't aware of the clever force multiplier effect of the diaphragm. I've confirmed that the landscape grade valves I use operate on this same principle (although the solenoids actuate on 24VAC, presumably because of the long cable runs required). I'll have to order a couple of these cheapies to play around with for toy aquaponic systems and the like. Come to think of it, I wonder if the valve may not positively close under low pressure intakes, such as gravity feeds...

A quite clever design. Thanks for sharing it with us.

Great explanation of how the diaphragm works, thanks!

Saw the thumbnail, thought someone invented the smallest flushing toilet. Dang.

Much appreciated - I was searching for info on this kind of unit literally just today.

Very Cool Teardown Clive. Keep up the great work. Nick.

not in a bad way, a good way, but your videos are so interesting and soothing that a lot of the time i fall asleep watching them lol

Agree with others here Clive that these are are common in washing machines where feed pipes fix to the rear of the machine itself.

there very good to use with a timer circuit as an automatic garden watering system for summer, ive done one in the past

Hi Clive, this is fantastic. We have 2 x 12volt solenoid valves on our boat toilets to control the flushing water. These have been a pain of my life for the last 10 years as they are always leaking when the small transfer hole blocks. Thus the water ends up continuing to flow and flooding over the bowl. That little tag on the spring to keep the hole clear is such a simple idea. My valves are made by Jabsco and cost over £100 each. I will be order 2 of these plus 2 more for spares asap. Thanks for the tip. I will post a video of these being fitted and a link to this video on our channel. PS Thanks for all your videos they provide endless hours of entertainment and information for us fellow geeks! 🙂

Spot on tear down. One item of note to those interested, don't ever activate a coil like that with nothing in the centre, the magnetic field created can actually burn the coil. At the very least run a screwdriver up the centre for testing purposes. I stumbled on your channel a couple of weeks ago, absolutely loving your content.

I thought these things worked like gate valves but there is a lot more going on. Elegant.

I use a lawn sprinkler valve to turn off all my water in the house until I need it. My water system leaks everywhere and I can't afford to replace it. So, rather than let the house be destroyed and my water bill go to extremes, I put the valve on my water intake. It has worked for several years, now.

I use one very similar connected to a raspberry pi that also has one of those soil moisture probes connected to it. didnt trust it on a mains fed water supply so it controls a gravity fed water tank that collects rainwater. Built it to keep my cucumbers watered in the summer but by the time I finished it the summer was over.. always next year...

Great video! I have learnt something! Thank you Clive! 🤗

I do love your videos! Great stuff

Great explanation. Very neat design.

I am a programmer. And now I know how solenoid valve works. Thank you! Subscribed. PS: oh wait, what am I doing?

the springy thing on the valve and stem is a anti hydrolock feature.

Great description mate. I learned something today. i work on the electronic end of things. was great to learn the mechanical side :) cheers

I like your videos it's like watching an episode of Absolutely!

Thank you for the explanaion. Now I know why they don't work unless there's lots of pressure. I need to open and close a tap that has no pressure!

Great explanation. Just to add - no wonder there is a filter and no wonder it is easily serviceable, because (I guess) in case of water not being perfectly clear it could easily clog those tiny holes.

It has been designed for low pressure which is why it has the extra spring. The important parts are the quality of the rubber and type of steel used in the plunger so it just not rust and jam. Same quality as used in you washing machine at a fraction of the price. but 230/110 volts Ex Factory FOB prices are around $1.50 -$3 on a lot of brands. If your lucky have a look on line you may see the same brand with a different fittings, and just change the inside round. Failure to fill fast is normally a small hole in the rubber part keeping the valve closed. Most were made in Italy a few years ago.

Apart from Elecronics as a hobby my fish pond is my next love and could find many use'es for this little gem

thank you Clive fascinating I do enjoy your videos it's like being at school all over again but more interesting. it's about time you blue something up again how much til that coil burns out?

Hi Clive, I think if you listen carefully to these valves in action on the job, you can actually hear that brief pause as the pressure equalisation is taking place on both sides of the diaphragm when the valve closes.I think it may be a requirement of the water regulations that an instantaneous water shut off on a main is to be avoided to prevent water hammer. The concussive shock can be quite considerable. Keep carrying on!

That diaphragm looks very similar to the one I have to replace on the inlet valve to my toilet cistern (every few years). I never understood how they worked... I just about get it now, but I think I will have to watch this video a few more times.

I am a heatpump technician work i whit so many different technical thing's looks a lot of what you do in the Dutch I like your video's

Excellent video. Do you know if those kind of valves can be used in a low pressure water system? I need to control the out of an IBC water tank and this might handy, but I'm afraid the water pressure would not be enough to make it fully operational. Thank you.

1:10 - KHAAAAANNNNN! Sorry, I had a Star Trek moment. ;-) It seems cheap enough that one probably would not want to disassemble it... And inexpensive enough to not bother rebuilding them if the diaphragm fails, just replace the whole unit for a few bucks. It is, however, a nice little unit to have for a clothes washer water inlet replacement if the original fails... I could also see it applied for light-duty irrigation, hydroponics, water features, even for DIY heat pumps. Quite a nice find, Clive!

I can think of a few very useful applications for this.

This reminds me of part of the breathing regulator used in scuba gear.

Thanks,i never knew what's that second hole for

Thank you big clive

lifts a glass to Big Clive!

Genius engineering!

brilliant explaination

Out of coincidence I've just fitted one of these to the inlet of my loft tank (in series with the ball valve), I'll let you know how long it lasts.

I use one of these solenoid valves connected to a ZJ-LCD-M flow meter on my brewery (real ale). I use it between the HLT and mashtun so I can measure the volumes of water. Works well most of the time but not and again it stops, I think the water gets too hot as the valves are rated at 80 degrees C maximum.

Oddly enough my old electronics teacher gave me the first explanation of these ingenious valves - I think the context was an automatic bath filler with temperature control. It never happened - we couldn't find low voltage ones at a reasonable cost...and tbh the idea was a bit rubbish... I'd fancy this for greenhouse applications or perhaps a PIR operated anti-cat watercannon.

Excellent explanation. Thanks...

Interesting film, thank you, learnt something :)

Great video, thanks for sharing

Entertaining as always. Question, i was looking online for a atx power adapter that would allow me to go from say the 12v rail and be able to adjust the voltage and current. I know about the little dangerous prototypes board as well as the little boost buck converters but i cant seem to find and dont know why just a box that you plug the 24 pin into and has those adjustments built in. Are you aware of such a thing? If not you should make em:)

i would say its probably aluminium bronze, its both cheaper to make than brass and has good corrosion properties.

I Wouldnt want to put much pressure through that.. It would blow apart.. I second the request for a work bench tour. Would be cool to see. Take Care..

That solenoid valve looks almost identical to one I replaced recently in a truly cheap and nasty Montpelier washing machine. The coil had gone O/C, I didn't investigate the reason.

I'd not be surprised if that Brass was DZR brass - allowing for variation in monitor performance, the shade seems "just right". The inline filter is a nice extra too - not particularly fine, but obviously someone's thought about this, and the end product is all the better for it. Chinese quality is RAPIDLY improving, and I'd expect the same transition in perception as we saw with Japanese cars - originally poorly-regarded, now the Industry standard.

You could make an auto dog water bowl filler with it having a weight sensor on a mat the bowl is secured to turn it off when the bowl is full or when the dog is present.

Can you do a review on the Thrunite flash lights? They seem very simple but cost a fortune.

Fantastic explination of a solenoid now i know why my washing machine makes a massive thud in the pipe as it stops water entering.

Did I miss something? Is it connected to the mains power through a power adapter? And how does it know when to go and stop. I'll have to watch again

Thank you for the great overview of the solenoid valve's operation. I was just about to buy one of these when I thought I'd check your channel for a review first! Was there any indication if the solenoid is connected to a diode for inductive voltage protection?

That device could had been used for a timed sprinkler system to water the lawn or a garden system similar to what some grocery stores would use for spraying mist on vegetables.

Nice! Your explanation is so much clearer than the textbooks ..... (or maybe it's just your mesmerising, mellifluous voice .....) What is the thread on the pipe fittings? Could you use 15 mm. olives and compression nuts? Or would it have to be hose connectors?

Great video ! thank you !

I want to see you use it to make a pulsed fountain display !

When I lived in England, I had a few just like this. In the states, I can't find one at the same cost with US threads.

Hummmm, Pretty good Mr.Clive.

big thanks

Can you post a link for the supplier? Having a problem finding it.

What is the max water temperature this would work with?

Could Clive be the actor in "The Gods Must be Crazy" film? In the film, he had a Land Rover with no brakes, no windshield and a dead battery. Over-tight pistons would not allow him to turn off the engine. Sounds like him and acts like him. If you have not seen the film, you must! Utterly hilarious.

Do gas valve diaphragms operate in the same fashion??

P.P.S. Can you post the link to buy this valve.

Just got urself new subscriber Good video

Thank You

possible PC water cooling application?

I tried using a solenoid valve like this to control a bucket-fed drip irrigation system, but it was a total fail because these valves require a certain amount of water pressure to work, and the bucket's few feet (less than a meter) of height was insufficient. Looking at your dissection, I guess that's because low water pressure is unable to press open the diaphragm. A motorized ball valve (off eBay) did work for me. They're more expensive, but would be cool if you could tear one apart some day.

How could we get this to work for a school project

yeah you could use it with an Arduino to make an automated watering system

You explained it really well, I wonder what the maximum pressure that it can cope with is?

Please make more videos like the LED rose you made recently.

are the springs stainless steel? a standard steel spring will rust very quickly.

I can't find that particular solenoid valve on ebay.

"Automated Plant Watering Devices" :P Sounds... interesting. xD

connect one of them onto your a/c condencer when she kicks on spray water on condencer it will blow ice cold i allways wanted to do that

water might push open and coil shuts off?

Does this water solenoid valve require water pressure to operate the closing and opening of the valve? Thanks

Looks like it is some sort of equilibrium valve.

Hello sir how can I use this valve in may wshe baisen tap

Hey Clive, great video as usual. That black and silver screwdriver (that you use), is it a pound shop one, I ask only because I bought one from my local pound shop. When I saw it I thought 'Big Clive has one like that'. I have also paused one of your vid's that have the said screwdriver in it, to get a good look. I think I have the same one as you.

Similar to a very old design from the days of steam, called the 'double-beat' valve, used for pressure relief/safety etc.

I hope you will see this if not I'll send it n patreon where do you get what you use to output specific voltages? What brand I'm sure it's in a video somewhere.

It looks very similar in function to a SIAMP diaphragm valve that my loo uses :-) Unfortunately they have a relatively short life span which is exacerbated by higher water pressures :-/

nice can it be feasible with water boiler

tried using these valves for airgun, found out that slightest hit to it could lead to actuation of the valve, thus rendering the gun unsafe whenever the reservoir is inflated up