Electronics controlled valve for cooking gas bottle?

[james_s]

Every RV (caravan) or marine store should have suitable valves on the shelf. They're used to control the propane from a panel inside the RV/boat.

[tggzzz]

Thanks,
Also, a gas cooker needs (and permits) a spark to be used to light it.
As such, how can it possibly ever pass ATEX approval?
Do you agree, ATEX approval and gas fires can never  happen?

Looks like the prediction I made in reply #29 is coming true. https://www.eevblog.com/forum/projects/electronics-controlled-valve-for-cooking-gas-bottle/msg4454536/#msg4454536

[LaserSteve]

Boy Scouts / Scouts USA requires two
 adults present for the use of Propane
for very good reasons.  I've seen what happens
when unsupervised Scouts toss a tiny disposable
Propane tank onto a very large campfire.

The thirty foot trail of large glowing embers landed
precisely over the two rows of summer camp issued
canvas tents.

I was the Senior Patrol Leader at a
 nearby campsite. I was wondering who brought
a grenade to summer camp when I heard the blast.
I was first on the scene, there were no cell phones
 back then and I didn't have a car.   No one was seriously hurt
The embers glowing on the tents was spectacular. Help was two miles away if needed.

Woe betide the camp counselor who allowed
that to happen, it was a provisional unit, Made
 up of Scouts whose Units were not attending
Camp. A few from here, a few from there. Next guy
on Scene was the Camp Chaplain, so this was not
getting "Hushed under the Rug, or Leaves" so to speak.

Children plus compressed gas do not mix well.

So I'm curious. Is this silly, idiotic, concept going into a confined space?    Fuel Air explosions cause a gruesome death, either by slow suffocation, infection from burns,or unrepairable
shockwave damage to internal organs.

No, No, No, No.  One kid with a screwdriver or vise-grips
wanting to bypass your controller for a hot Coco or popcorn, and you have a problem.

 I wish I could  introduce you to my childhood friend Tom.
He's no longer with us after a FAE refueling a lawnmower.
Oh, he survived for a few years, but the rejection and cruel
words over his skin grafts by teenage girls did him in.
Had a heart of gold.

No, just don't. Gas requires adults.

This from a fellow who was quite the teenage experimentor.

My employer,  a university,  has went out of it's way to eliminate flammable gas burners in labs.  For the only thing worse then a child is a distracted graduate student.


These lessons are learned in blood.


Steve

[floobydust]

[...] So I'm curious. Is this silly, idiotic, concept going into a confined space?  [...]

Don't bother you can't dig in - we are always fed vague, fictional requirements.

Thanks,
Also, a gas cooker needs (and permits) a spark to be used to light it.
As such, how can it possibly ever pass ATEX approval?
Do you agree, ATEX approval and gas fires can never  happen?

Looks like the prediction I made in reply #29 is coming true. https://www.eevblog.com/forum/projects/electronics-controlled-valve-for-cooking-gas-bottle/msg4454536/#msg4454536

Hey you've figured out the troll algorithm. Find any way to rationalize seeing only what you want.
I worked under a CEO like this, he tried very hard to rationalize that no safety standards applied to a combustion product using natural gas. It caused great hardship for the engineering dept. as he is the top boss yet a few people would not go along with it, including myself.
It is caused by low intellect, no conscience and no patience to research, design and build a safe product that would pass approvals, he just wanted profit ASAP and someone else to be the fall guy for any legal reasons.
I kept his document debating why the product needed safety approvals, which included customer perceptions and costs vs. profits if an explosion occurs. He deleted the doc off the server and I copied it back over lol. It's good reading into the mind of a psychopath trying to justify what they want, whereas the rest of humanity uses common sense.

I've never seen micro-power gas valves, latching ones included. Smallest is RV propane refrigerators (12VDC and ~1W) and IR remote-control gas fireplaces that have no mains power (only mV thermopiles) it was a 4xAA 6V system for flame control.

[Faringdon]

Thanks, these are great replies...i am going though and through them.......i am seeking that "proof" that this project (in whatever manifestation)  is a "no-go" project now, as all are very negative towards it.
We wont do it, if the benefits are destroyed by the lack of safety.
We wouldnt use something if we wouldnt use it ourselves.

I am reading your kind replies to separate out what hazards are particular to just our system, and those hazards that are also  particular to existing gas cooking solutions which do meet approvals.

The "idea" is a good one.
Eg, Getting cooking possibility to the bombed out people of Ukraine.
It unfortunately does need some kind of token rationing.
And does need not to be mains connected, as power sources  are scarce.
It also has to be borne  in mind, just what the Ukrainians will do with gas cannisters...if no-one helps them at all with any solution......they may well do something even more dangerous than the system we suggest here.

If i was in a Ukrainian bomb shelter, i would like the system of this post...but would also  like a manual valve also inline with the electronic  one.....so i could manually shut off the gas when finished cooking.
Also would like thermocouple flame fail detect....so will need some InAmp circuit


BTW, we have wrote to many companies asking for a valve like ours. (Low voltage, no current draw  after actuated)
The following ones, have very quickly just come back with a "No".......

BES
Solenoid-valves.com
Hamilton Gas products
EPH controls

So it looks like at the very least, we are looking at a custom valve here.

[tggzzz]

Thanks, these are great replies...i am going though and through them.......i am seeking that "proof" that this project (in whatever manifestation)  is a "no-go" project now, as all are very negative towards it.

Why on earth are you seeking proof? Is it just a troll-like technique to keep people wasting their time by responding?

Just drop it.

[Brianf]

3..Do you have any ideas for low-bias-current current limiters that we will need due to the ATEX approval?

If you are aiming for ATEX certification then don't forget to budget somewhere around £20k-£30k to get it. ATEX certification requires the use of an approved third-party ATEX test house, it's most certainly not something you do yourself.

[fourfathom]

BTW, we have wrote to many companies asking for a valve like ours. (Low voltage, no current draw  after actuated)

In one of the first posts here pcprogrammer linked to a bunch of motor-driven ball-valves: https://www.eevblog.com/forum/projects/electronics-controlled-valve-for-cooking-gas-bottle/msg4451872/#msg4451872  These shouldn't need power after actuating.

BTW, I'm not saying that any of this is or isn't a good idea.

[Gyro]

I still don't get how the narative has changed from "These are for kids camping chalets" to Ukranian bomb shelters 

It sounds as if some fundamental project parameters need tying down before proceeding anywhere!

[pcprogrammer]

I still don't get how the narative has changed from "These are for kids camping chalets" to Ukranian bomb shelters 

Is it just more proof for trolling

[joeqsmith]

I've seen remote bottle openers like this:

https://www.nitrousexpress.com/automatic-remote-bottle-opener-11107.asp

I use their solenoids. 
https://www.nitrousexpress.com/nitrous-and-fuel-solenoids/

There are many OTS gas valves available for all sorts of applications.   

[LaserSteve]

Stop feeding this troll. That  seems to be the best course of action.

Steve

[TomS_]

There wont be any lawsuits. Thats all i can say. This just needs to be designed to be safe to  "people behaving sensibly

And yet here we are with RCDs because people used hair dryers in the bath tub, and warning labels on bottles of bleach that you shouldn't drink it.

If you honestly think that the general population can be trusted to be sensible then you are asking for that lawsuit...

But I dont see why this needs a "new" solution. Coin operated BBQs are a thing already, and have probably undergone all of the required safety checks/tests/certifications. As much as I like to build something from scratch, I would save myself the trouble in this instance and buy a commercial product. At least there would be someone to blame other than myself if something goes wrong.

[MK14]

There seems to be a similar, but ended up different (in that there is no mention of Ukraine, that I can see), here:

https://www.electro-tech-online.com/threads/cooking-gas-bottle-valve-controlled-electronically.164000/

Apparently (presumably) by the same Author/OP.

They (the other people, on the other forum), also took the time and effort, to carefully explain that the gas might be leaking a bit, and the slightest spark (e.g. from electronics), could cause an explosion.  But, instead of accepting (presumably) (semi-)expert opinion, they (OP) go, yada yada yackidi yack, what if blar blar blar, and ignore the point entirely, and (I don't know what they are thinking, so I'm guessing, here) seem to suggest the safety gas regulations should/can be ignored (is the gist of it, I seem to get, from a very quick read though of it).

The idea of safety rules and regulations, is to attempt to make things safe, even if the person is a clueless uneducated, somewhat reckless, individual, with poor common sense.

But unfortunately, there are always those people, who ignore safety (and other) regulations.  So, they shouldn't touch many things, including gas equipment/design, with a very long barge pole.

Hi

We are designing and building cooking gas bottles with valves. These are for kids camping chalets. Its purely a safety feature because its kids. As you can tell, there is no big market for this product, its just to get these kids out camping.

System description:
So we have a bottle of cooking gas with a valve which is opened/closed by a small motor. The valve assembly sits on top of the gas bottle. The kid inserts a token (like coin) into a box, and then they get the gas valve opened for 10 mins, then closed again, until another token is inserted. The token box is near to the valve box and is electronically connected to it via a small cable. Which passes though the enclosure walls.

A STM32 micro in the valve assembly contols the valve motor. The micro will be sent to sleep whenever possible. The power to drive the motor comes from a small lithium cell with cell voltage of ~3.6V. There are no SMPS’s in the product. (because we need standby power to be very low). The motor is simply driven directly from the battery. (FET switch, switched by micro). The battery is non-rechargeable, as these have lower leakage current and last longer. The battery voltage is flat at 3.6V for most of its cycle..therefore we cant use battery voltage to sense when the battery is flat. So we intend to do some kind of coulomb counting.

Because its gas, the valve assembly product needs ATEX approval.

When the motor has fully closed (or fully opened) the valve, we don’t want the motor drawing any power, so I guess we need some mechanical latch in there. We can’t use a latching solenoid valve as they draw too much power in operation and in standby. They draw a high current when first actuated, and the ATEX approval means all our currents need to be well limited.

We need to sense when the motor has got to the end position where the valve is fully closed (or fully open)…We are thinking of doing this by sensing the motor current..because when the motor hits the end stop, then its rotor will cease rotation, and thus give no back EMF…so the rotor current will suddenly increase….we will detect this so as to tell us when the motor has reached the end stop.

..However, we were also thinking of adding a double check to this, by way of a Hall Sensor stuck to the rotor…so we can check the motor really has got to the end stop…after all, the user may somehow yank it so the motor stops in the wrong place (valve not fully open/closed). We are also worried that the user may try and somehow force the valve to be always open (so they can get more gas)

Questions:
1..What type of motor do you think can be used for this? (we aren’t finding such low voltage motors for this). Presumably DC motor is a no-no due to brush sparks and the gas (ATEX approval needed)?
2..Do you know of any kind of existing product on the market anything like this?…even if its not for cooking gas….…we cant find any.
3..Do you have any ideas for low-bias-current current limiters that we will need due to the ATEX approval?
4..Why dont normal gas cookers need ATEX approval?..they must have electronics in them.

[LaserSteve]

Attached is a pic of a unit that was approved for the job. Meets all the international requirements etc.
No batteries, and obviously only affordable in large scale use. Might have a little issue finding Shillings that were not melted for scrap value.  Incredibly reliable and safe when properly installed.

After the Ukrainian Farmers bypass this unit, I'm sure they Will have a photo of an APC, probably a BMP-2, filled with coin operated gas meters going to the scrap yard. Towed by a mighty John Deer..

[Terry Bites]

Ah yes, the royal we.

[Faringdon]

They (the other people, on the other forum), also took the time and effort, to carefully explain that the gas might be leaking a bit, and the slightest spark (e.g. from electronics), could cause an explosion.

Thanks, AYK, there do exist electronic gas valves, which pass regulations, and exist on equipment which passes regs,  this is what prevents us from binning the idea.

[MK14]

Thanks, AYK, there do exist electronic gas valves, which pass regulations, and exist on equipment which passes regs,  this is what prevents us from binning the idea.

Did you try, this company:

https://www.tlxtech.com/solutions/operation/latching

[tggzzz]

Stop feeding this troll. That  seems to be the best course of action.

I never like jumping to that conclusion. I prefer to attribute such behaviour to stupidity/perversity rather than malice.

Nevertheless, sometimes stupidity or perversity are not a sufficient explanation

[pcprogrammer]

It would be interesting though to know what is really behind this all. Is it indeed a simpleton trying to make a living or someone with a perverse intelligence pulling us into responding to his silly questions? And how, if the latter is the case, does that provide fulfillment for him?

And for sure Faringdon has asked some silly ones, like the thief ability of scopes or the wetting my floor to avoid static discharge

Can't speak for others, but I have fun in participating

[tggzzz]

It would be interesting though to know what is really behind this all. Is it indeed a simpleton trying to make a living or someone with a perverse intelligence pulling us into responding to his silly questions? And how, if the latter is the case, does that provide fulfillment for him?

There are other, somewhat sadder, possible explanations.

And for sure Faringdon has asked some silly ones, like the thief ability of scopes or the wetting my floor to avoid static discharge

I remember the former (which has some vague plausibility until considered in more detail), but I must have missed the latter!

Can't speak for others, but I have fun in participating

Iff that's understood then it isn't a waste of your time.

[pcprogrammer]

.... but I must have missed the latter!

https://www.eevblog.com/forum/manufacture/spraying-wooden-floor-with-water-to-reduce-esd-damage/

Iff that's understood then it isn't a waste of your time.

That is the beauty of retirement, got all the time in the world

[tggzzz]

.... but I must have missed the latter!

https://www.eevblog.com/forum/manufacture/spraying-wooden-floor-with-water-to-reduce-esd-damage/

Oh, that one is really quite "special"! It clearly heightens the troll-vs-idiot-vs-X question.

Iff that's understood then it isn't a waste of your time.

That is the beauty of retirement, got all the time in the world

Not so. Your micromorts are increasing all the time. https://en.wikipedia.org/wiki/Micromort Which means it is increasingly rational to take more risks in the pursuit of fun

[pcprogrammer]

Not so. Your micromorts are increasing all the time. https://en.wikipedia.org/wiki/Micromort Which means it is rational to take more risks in the pursuit of fun

  Did not see laughing behind a computer mentioned as a micromort risk 

[tggzzz]

Not so. Your micromorts are increasing all the time. https://en.wikipedia.org/wiki/Micromort Which means it is rational to take more risks in the pursuit of fun

  Did not see laughing behind a computer mentioned as a micromort risk 

I like the concept of micromorts (and the associated microlife https://en.wikipedia.org/wiki/Microlife ) since, in a very understandable and useful way, they cut through a lot of crap about safety/danger.

Spiegelhalter is one of the people I always listen to; he is good value for my time.

BTW: my edit and your posts crossed in the æther by 3s. I emphasised my point with "...means it is increasingly rational..."