heres a gas pressure vessel can i get some advice. - Page 1
Forum section: electronics / general

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 01:53:36 pm
content: https://www.ebay.com.au/itm/294264768696?chn=ps&_ul=AU&norover=1&mkevt=1&mkrid=705-139619-5960-0&mkcid=2&itemid=294264768696&targetid=309727335774&device=c&mktype=pla&googleloc=9070552&poi=&campaignid=1669056926&mkgroupid=67513082834&rlsatarget=pla-309727335774&abcId=1123846&merchantid=119156995&gclid=CjwKCAiAvaGRBhBlEiwAiY-yMDpoKYB-EGJQgDzgFYp5-_z-s1RTHSYFSjfLYNfHlYc7dxvjyYn-WxoCZuIQAvD_BwESo this pressure vessel looks ok. but I'm not sure what I'm doing, I'm not sure how much pressure this thing can take.Maybe if It comes with a psi-dial I guess keep below the max on it.I'm planning on putting pure oxygen in it, (Using electrolysis and a high psi low volume pump to get it in, into a rated diode.) Only slowly over time, using baking soda as the electrolyte, and out-piping the hydrogen cause I don't need it, I figure lightning will hit it and it'll turn back into water again. good old nature.Im going to convert it into a multi-compartment system, with cement and plastic bottles (because it could possibly have a strong base in it -according to a theory- that could react to the metal, so I figure plastic and cement to fill up the gaps inside gets over the problem.)Thats if my theory is correct anyway about dissolving oxygen at high pressure with water creates a strong base, whilst the oxygen in inside it, and kept at icy cold temperature. (look up Henry's law.) Its a diacidic base. at 2000 psi i think it only counts as 90% diluted only, so the material will probably be hydrous only, not anhydrous, and I probably wont even reach that pressure, depends on what its all rated at when it gets to me.Its because I want to put magnesium oxide in solution, to cement it together from powder. (Ceramic-ware)I want to make things like ceramic scissors and other apparatus, maybe even cooking ware, but that will only work if it doesnt come out too hydroxidey, or when heat hits it, it might break apart in powder, when it loses its water bonds. If its not affected by the water too much, itll take more thermal torture before it breaks, like concrete kilns do. But maybe thats a bit too much to ask, and its not thermal ceramic.Instead of using acid, I put it with high pressurized gas and water instead, but its a similar thing. it puts the rock in a softer state so it melds together. Its like scintering, except I do it at 2 degrees instead of 500 degrees, because the gas pressure should push it together, so the base acts on it, it goes soft, then it gets 1000 psi of pressure (or whatever I manage to get.) compacting it together pneumaticly.I need it multicompartment, because i need the water to travel out of the "mud slurry" in the mould, and drip into a condenser, I plan on doing it with vibration evapouration.Ill probably just put in the refridgerator (cold gets the gas more dissolved for the same pressure, squared just about, cause of thermo-dynamics), if I can make some space for it, and just sit it in there and see if the mag-o crystalizes, with the oxygen bombarding it.So, any one have any advice? Or am I completely insane.

author: TimFox
author_rank: Super Contributor
timestamp: March 09, 2022, 02:09:51 pm
content: In chemistry labs, such vessels are often called "bombs", which is a hint about safety. This one looks something like an old-fashioned kitchen "pressure cooker", which usually hold about 2 atmospheres pressure, nowhere near 1000 psig.Of course, the vendor doesn't specify the pressure and the gauge is illegible. What kind of seal (gasket, whatever) is below the top?Even the kitchen units occasionally explode, so I will not give practical advice on this unit.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 02:13:05 pm
content: Thanks.I can actually make one myself out of cement. I wonder how thick it needs to be, and how much steel reinforcement bars help.So I need a rubber gasket for it! - then maybe I can strap it down with some 1 tonne buckle straps.

author: bill_c
author_rank: Regular Contributor
timestamp: March 09, 2022, 02:41:46 pm
content: Please don't do this!You can rent oxygen tanks at welding supply places. These tanks are heavy forged steel.Oxygen service has special requirements. Just about anything in contact with the oxygen is seen as fuel. Things like excessive velocity, oil contamination, and plastic, can set it off. Do way more research before attempting such, even with approved tanks, piping, and controls.Also, cement (or concrete) does not have any tensile strength, so it is not suitable for any pressure tank.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 03:01:33 pm
content: I bet cement can take some pressure, its thick rock, But If I just use it as filler for inside a pressure capsule I buy, it only needs compressive strength to be ok. (because its sandwiched between the inner membrane (plastic bottle) and the wall.So... with the oxygen, yeh I dont know what I'm doing at all.I heard u can actually light a cigarette on contact to liquid oxygen, but I need something powerful otherwise the mineral isnt going to "glue". What I think im getting (which is a pretty loose theory) is something like liquid oxygen but at 90% dilution of that.Is that still dangerous? And will plastic linings still work? I'm not sure, but plastic is unaffected by pure sodium hydroxide, so I think it should be ok to handle compressed oxygen and water vapour mix.Yep. more research is in order.And I may just do a little 100 psi version with just pepsi bottles in the refridgerator ... before I go hardcore straight away.

author: IanB
author_rank: Super Contributor
timestamp: March 09, 2022, 03:30:11 pm
content: 1. Do not mess with gases under pressure2. Do not mess with pure oxygen3. Do not, repeatdo not, mess with pure oxygen under pressureI'm not kidding here. Maybe you will manage to avoid harm or injury, but maybe you won't. It's not worth the risk.

author: rstofer
author_rank: Super Contributor
timestamp: March 09, 2022, 03:46:42 pm
content: The dispenser tank in the OP has a pressure relief valve - don't defeat it.If you scroll through the images, you will find one of the open tank. You can see that the walls are quite thin.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 03:56:12 pm
content: Quote from: IanB on March 09, 2022, 03:30:11 pmSo... how dangerous is it really- is it as good as compressed hydrogen?Thats pretty bad. Have a compressed hydrogen explosion could be quite the spectacle.I always thought oxygen doesnt actually ignite by itself?

author: TimFox
author_rank: Super Contributor
timestamp: March 09, 2022, 04:01:05 pm
content: If you have to ask "How dangerous is it really?", then you need to do some thorough research at the library before further consideration.If you think you can rely on the compressive strength of cement between flimsy walls, with amateur-produced concrete, you should realize that serious construction projects reinforce the concrete with rebar.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 04:17:06 pm
content: I just did a rebudgetting, and because my system volume is only 4 litres, To pull in 2000-psi's worth of oxygen is only 2metres^3. but because the air is only 25% oxygen, its 2x4x4 metres takeup in natural air at 14 atm, so thats not that much.When I let off the release valve, it wont take very much to expand back to normal pressure.if i keep the volume down (to say tops 4litres and its only little system) I can get the psi up and its not as dangerous.If I released it out slowly when deflating the system, I bet its perfectly safe, just don't make an oxygen jet and it'll be perfectly fine.

author: IanB
author_rank: Super Contributor
timestamp: March 09, 2022, 04:28:08 pm
content: Quote from: Capernicus on March 09, 2022, 04:17:06 pmDo you want to bet your life on that? Even if you don't get killed, you probably value your eyes, ears and limbs, right?

author: TimFox
author_rank: Super Contributor
timestamp: March 09, 2022, 04:28:56 pm
content: Again, why do you think 1000 psig in this container is not dangerous?

author: IanB
author_rank: Super Contributor
timestamp: March 09, 2022, 04:31:20 pm
content: Quote from: Capernicus on March 09, 2022, 04:17:06 pmSo a little bomb is not as dangerous as a big bomb? Yes? But is a little bomb something you want to be around?

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 09, 2022, 04:34:27 pm
content: You aren't playing with fire here, you're playing with what makes fire work, in a highly concentrated form.Such shenanigans tend to result in closed casket funerals.

author: HighVoltage
author_rank: Super Contributor
timestamp: March 09, 2022, 04:34:31 pm
content: To me it sounds like you do not know what you are doing and you have no feeling for the level of danger you are getting yourself into.There is a reason why compressors and bottles with compressed gases have to be inspected on a regular basis.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 04:39:48 pm
content: Its only 4-litres, so if u expand it to be at the natural dilution of air, its only 2x4x4 metres cubed.I think ill be fine.So whats the danger here, its completely isolated from its environment, and if I need to discharge it, I just do it slowly over time and theres no chance for explosion at all.If it has a safety valve on it, there's no way I can overfill it, and if I do, Im also only filling it slowly so that should be safe too.

author: KaneTW
author_rank: Frequent Contributor
timestamp: March 09, 2022, 04:42:38 pm
content: If you want to commit suicide, please don't involve us.

author: Monkeh
author_rank: Super Contributor
timestamp: March 09, 2022, 04:52:45 pm
content: This is the sort of thing you're playing with. Please stop.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 05:09:15 pm
content: acetalyne may as well be petrol, oxygen is different, as long as u don't enrichen the air too much then there's no chance for any fire hazard.The gas going to everyone's home right now for cooking is more dangerous than it, if I be careful it should be ok.Should just put some engineering hairs on my chest. I cant wait to do it.* no leaks.* charge and discharge slowly to not enrichen the air.* make sure the whole thing is acid and base proof.* always fill it up at a higher temperature than I use it at.theres no way to make a strong material without having to go through some danger. So this is perfect, its not too bad, because magnesium oxide is very water soluable, (0.009 grams for 100millitres of water, quite high for an oxide!) so the base should affect it very well.

author: Monkeh
author_rank: Super Contributor
timestamp: March 09, 2022, 05:18:16 pm
content: You're talking about putting 1000psi into a thin-walled steel cylinder. It may as well be acetylene if that ruptures.I can't tell if you're a troll or just this dumb..

author: MK14
author_rank: Super Contributor
timestamp: March 09, 2022, 05:19:58 pm
content: Quote from: Capernicus on March 09, 2022, 01:53:36 pmI'm saying, nothing.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 05:26:12 pm
content: So what could cause it to rupture and explode?is there a vid of a 4litre bottle at 2000psi going off, I wonder how big the explosion would be.

author: MK14
author_rank: Super Contributor
timestamp: March 09, 2022, 05:32:23 pm
content: Quote from: Capernicus on March 09, 2022, 05:26:12 pmNo, I could only find videos of a 3.99999 litre bottle at 2000.00001 psi and another video, with 4.00000000000001 litres, exploding at 1999.999999 psi, so it must be safe ?End of sarcasm.No, It doesn't sound safe at all.

author: nali
author_rank: Frequent Contributor
timestamp: March 09, 2022, 05:32:45 pm
content: Warning: This is a little bit gruesome!Someone playing with an O2 cylinder learned the hard way. Please don't.O2 CYLINDER EXPLODES WHILE BEING REPAIRED (STILL PHOTOS)

author: nctnico
author_rank: Super Contributor
timestamp: March 09, 2022, 05:37:14 pm
content: Quote from: Capernicus on March 09, 2022, 01:53:36 pmThis is not a pressure vessel; this is a container used to dispense liquids (like Coca-Cola) which are forced out by a compressed gas at pressures of a few bar (<4) at most.Like others already wrote: your project sounds like a complicated way to kill yourself.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 05:38:57 pm
content: whatever you do, dont buy an oxytorch.

author: Monkeh
author_rank: Super Contributor
timestamp: March 09, 2022, 05:41:27 pm
content: Quote from: Capernicus on March 09, 2022, 05:38:57 pmI've used them quite safely, because I understand how flammable gasses and accelerants behave.FYI, the E size cylinder in the video posted a few minutes ago is 5l internal volume. And probably exploded like that simply by the effort of attempting to unscrew the valve.

author: IanB
author_rank: Super Contributor
timestamp: March 09, 2022, 05:44:02 pm
content: Quote from: Capernicus on March 09, 2022, 01:53:36 pmQuote from: Capernicus on March 09, 2022, 03:01:33 pmQuote from: Capernicus on March 09, 2022, 03:56:12 pmQuote from: Capernicus on March 09, 2022, 04:17:06 pmQuote from: Capernicus on March 09, 2022, 04:39:48 pmQuote from: Capernicus on March 09, 2022, 05:09:15 pmQuote from: Capernicus on March 09, 2022, 05:26:12 pm

author: Monkeh
author_rank: Super Contributor
timestamp: March 09, 2022, 05:44:47 pm
content: Quote from: IanB on March 09, 2022, 05:44:02 pmDunning-Kruger in action.

author: jmelson
author_rank: Super Contributor
timestamp: March 09, 2022, 05:48:28 pm
content: Pure oxygen is extremely dangerous. There have been fatal explosions where commerical oxygen bottles have caught fire and exploded due to minute amounts of oils or even fingerprints on internal parts. There was a recall of medical oxygen bottles which came with brass regulators where the wrong grade of brass was used. Almost all materials are combustible in even standard atmospheric pressure pure oxygen. The US Air Force did a test back in the 1950's to see if airmen would be harmed by breathing pure oxygen. Somebody changed a burned-out light bulb, the spark when the new bulb made contact ignited the light socket, the ceramic socket then ignited, an asbestos fire blanket then ignited, and the opened the door and barely escaped. Check out the Apollo 1 fire in 1967 that killed 3 astronauts. Slightly above normal atmospheric pressure, pure oxygen. The whole Apollo capsule was incinerated. Also, check out the Egypt Air flight 667 fire in a Boeing 777 at the Cairo, Egypt airport. A wire sparked to the crew oxygen line, and burned the cockpit to a complete cinder. If that happened in the air, it would ahve been a catastrophe, but they were still parked at the gate.Jon

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 06:11:25 pm
content: Quote from: Monkeh on March 09, 2022, 05:41:27 pmYeh I see now, Whats the flammable and whats the accellerant out of hydrogen and oxygen.It could be the other way around.Ones + and ones -, they are both flammable, its when they hit each other where the problem is.

author: Monkeh
author_rank: Super Contributor
timestamp: March 09, 2022, 06:12:39 pm
content: The accelerant is oxygen and the flammable isabsolutely everything around it, including metal.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 09, 2022, 06:31:31 pm
content: soda bottle plastic?

author: TimFox
author_rank: Super Contributor
timestamp: March 09, 2022, 06:48:18 pm
content: Be sure to get your entry inante mortem.https://darwinawards.com/

author: IanB
author_rank: Super Contributor
timestamp: March 09, 2022, 06:50:12 pm
content: Quote from: Capernicus on March 09, 2022, 06:31:31 pmDoes plastic burn?As a rule of thumb, things which don't burn are combustion products like ash. If the thing you are looking at is not already burned, it is likely it will burn. This means that most things are flammable (including metal).

author: TimFox
author_rank: Super Contributor
timestamp: March 09, 2022, 06:53:19 pm
content: https://www.fire.tc.faa.gov/pdf/05-14.pdfSee pp 18ff for data on common plastic bottle materials.Do you have Google?

author: LaserSteve
author_rank: Super Contributor
timestamp: March 10, 2022, 03:23:56 am
content: When I was learning glassblowing as a high school junior I learned not to wear sweaters with the torch running. Even with balanced combustion going on, enough gas combustion products and unburned oxygen would build up in the cable knit sleeve that I could smack my arm with my hand, and the gas would travel to the torch and ignite with a whump. That was an eye opening experience.Please see attached pictures of a car with a compressed gas expansion incident.. First the released gas expanded the car. Then it exploded AFTER an ignition source was found.Find some one experienced with Sol-Gel chemistry and have a chat with them. Ask them to show you a real certified and proof tested pressure vessel. It looks nothing like what you have pictured.Google ASTM pressure vessel and read what you find.Hydrothermal crystal growth does not need the satursted o2, either. But it does need a proper pressure vessel that weights tonnes and operates in an armored containment facility, by remote control.Please don't try what you propose.Note, I deleted the politically incorrect "Man from Lox" from my post. Sadly it is a wartime video, and probably inappropriate for EEVblog. The demos in-between the sexist portions are very good, and show what unconfined oxygen at low pressure can do.Steve.

author: SmallCog
author_rank: Frequent Contributor
timestamp: March 10, 2022, 04:50:27 am
content: The pressure vessel you linked has a table with a column labelled bar.Presuming this is it's maximum, the value of 8 equates to 116psiGiven that the vessel has a flat top and bottom I'm surprised it's even this high, the more pressure a vessel is designed to take the less chance you'll see a flat surface.I'm not sure which state you're in but what you propose may require registration given the pressures and substances. A basic guide can be found here:https://abvinspections.com.au/wp-content/uploads/2019/05/Guide-to-Pressure-Vessel-Item-Registration.pdfI've been through the pain of registering a pressure vessel that was purchased and imported into Australia without any consideration given to registration. Its not something I'd ever willingly tackle again!

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 05:22:52 am
content: Quote from: SmallCog on March 10, 2022, 04:50:27 amThanks for spotting - I bet it can take way more than 100psi, that's a very careful max for a steel container, a pepsi bottle can take 100psi.With the oxygen, thanks for all the advice, Ill definitely do some more research before I go for 2000psi. (100psi should be safe tho. even for oxygen.)So I best be careful when I do this. I'm not even sure its going to work, I pretty much know it works for Co2, so I'm just generalizing the idea to oxygen.

author: bdunham7
author_rank: Super Contributor
timestamp: March 10, 2022, 05:40:40 am
content: Quote from: Capernicus on March 09, 2022, 05:26:12 pmSimply contaminating the threads of an oxygen valve or regulator can do it. A 4 liter bottle at 2000psi would be more than enough to splatter your brains on the ceiling.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 06:39:59 am
content: Quote from: bdunham7 on March 10, 2022, 05:40:40 amI AM LISTENING. I'm going to call it off for more research time on all the pit falls, especially for oxygen, for sure.I need to do this tho, or I'm basicly getting nowhere.a 4liter bottle at only 100psi has got to be safe tho? Even that "drinks dispenser" goes up to that much on the dial, even tho I know its only co2 that goes into that thing.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 06:52:24 am
content: I could actually drop the volume to 200ml.because I just have to support the mould + a little condenser volume next to to it for the water to evaporate/wick out to.So it could be less than 4litres easily, so maybe I should do that.Once the rock has all the water removed from it, it should be hardened by then. u slow down the evaporation to get it to the time duration you want.The amount of air im compressing in for that. (and only getting the oxygen not the nitrogen) would only occupy a half metre cube of ordinary air, so if i keep the volume down its probably nowhere near as dangerous.

author: LaserSteve
author_rank: Super Contributor
timestamp: March 10, 2022, 06:52:58 am
content: 100 psi from a fractured pressure vessel can inflate your arm like a balloon. Didnt get to see that one but heard about it from the inflatee.Our.stainless Sol-gel reaction vessel at work has at least 25 mm walls, volume of say 10 L, weights around 350 pounds, has a hydraulic jack to lift its lid, copper seals, and 12 grade eight bolts to hold the lid on.Manual calls for a torque wrench to a specific torque or safety ratings are void.The pump can deliver up to 5000 psi Co2 on that system.No rubber or plastics anywhere in the system. Lots of warnings in the manual about purging the gas fill to avoid various problems including autocatalytic reactions.Something else to think about, if your supersolvent will dissolve a ceramic precursor, what will it do to a rubber seal?Steve

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 07:52:32 am
content: Quote from: LaserSteve on March 10, 2022, 06:52:58 amIf I keep my system to 200ml, at 2000psi, its ~50 times less force than your system has to take at 10litres. (PxV) maybe doing things low volume is alot less catastrophic.the "Super solvent" which I don't know is going to work, is just pressurized oxygen inside the ceramic mud slurry inside the mould cavity, which is to be pressurized. (which is kept 2 degrees, for more gas dissolution.) Since Ive just worked out from what you guys said to me, that oxygen is alot more dangerous than co2, maybe the base it makes is also more concentrated at an equal pressure, co2 only makes a dibasic acid, oxygen might not be as diluted when mixed with water.Plastic is safe from acid and bases no matter how concentrated they are - thats what I thought. Its rocks + metal that get affected by acid+base, not plastic+rubber?So do you know alot about oxides? Sol-Gel I never heard of that before... I just want to make ordinary magnesium oxide, Now Im starting to think with 2000 psi, maybe it literally just squishes the water out of it, and it only takes 30 seconds, and I was thinking I need to leave it in there for a month under pressure.And I dont know. I should definitely do it low pressure first, to see what happens. Then increasing the pressure may have an effect that it literally dries it by squeezing the water out of it mechanically!!!

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 08:32:19 am
content: What if I dig a big hole and operate it under the ground? That might be safer.

author: newbrain
author_rank: Super Contributor
timestamp: March 10, 2022, 09:55:06 am
content: Quote from: Capernicus on March 10, 2022, 08:32:19 amSix feet under would be perfect.I'm starting to suspect you are trolling and getting a good laugh out of well meaning persons.If you are not, please desist.

author: Gyro
author_rank: Super Contributor
timestamp: March 10, 2022, 10:22:57 am
content: Quote from: Monkeh on March 09, 2022, 05:18:16 pmLooking at the OP's YouTube channel, I think you'll need to wait for him to come down from whatever he's smoking before he will be in any state to take warnings seriously.EDIT: Deleted link, not giving his sick views the light of day (see reply #83)I initially thought he was a young kid but...no.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 11:49:18 am
content: Nope I'm being perfectly serious, I am not wasting your time.If it happens to be too dangerous to post here because in general you don't want ppl doing it at random thats ok by me.Getting a pressure vessel, and using it somewhat dug in the ground probably isn't a bad idea if u can do it that way. It would muffle any castastrophic explosion, if it ends up happening.So I am going to very careful when I do this, I'm actually going to to leave it a bit before I do it, bit of post-ponement... need to collect more info.

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: March 10, 2022, 01:58:17 pm
content: Some things to consider:- everything burns in presence of oxygen, steel included.- oil contamination, even if small, will make the rest of your life difficult.- oxygen, even at "low" pressure explodes. Think more like a grenade and not a balloon- we have strict standards on pressure vessels for a good reason (people dying if ignored mostly)- for reference, I have a 3 cubic meter tube for welding that is rated at 2500psi. When empty it weighs 30kg / ~60pounds. And it's not "big" by any means.Also, please setup a livestream of your experiments so we can later use those as a teaching aid to avoid accidents.

author: Monkeh
author_rank: Super Contributor
timestamp: March 10, 2022, 02:01:38 pm
content: Quote from: Gyro on March 10, 2022, 10:22:57 amErr...On second thought perhaps we should let nature run its course here.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 02:24:05 pm
content: pardo-bbso...Thanks for the tips.Could u elaborate more on oil contamination, and what exactly can cause oxygen explosions?Have u ever had your bomb at full psi? (the full tonne?)

author: Ian.M
author_rank: Super Contributor
timestamp: March 10, 2022, 02:51:31 pm
content: Re: Oil contaminationHigh pressure or liquid Oxygen + just about any organic compound or finely divided particles of many metals = high yield explosive. Seehttps://en.wikipedia.org/wiki/OxyliquitJust about any impact, friction or ESD can detonate it, even if the triggering event only initially creates a nano-scale hotspot.If you live out in the boonies and can set up your experiments to be entirely performed in a pit out in the middle of the 'back 40', using CCTV and waldos from a bunker at a safe distance, by all means go ahead. If you are in an urban or suburban area, don't even consider messing with high pressure Oxygen!

author: TimFox
author_rank: Super Contributor
timestamp: March 10, 2022, 03:15:16 pm
content: A similar technique, critical-point drying, is used to prepare microscope specimens, and uses similar pressures with similar hazards.You could start with the document linked by Leica:https://www.leica-microsystems.com/science-lab/brief-introduction-to-critical-point-drying/This technique was new when I was in grad school, and we heard several horror stories about explosions in laboratories. As I mentioned earlier, the pressure vessel used is called a "bomb" for good reason.Leica mentions pressures up to 74 bar (1000 psi) for CO2, and considers the 229 bar (3300 psi) required for H2O to be impracticable.The bombs used for this process are serious constructions, not Pepsi bottles or pressure cookers. One unfortunate incident involved a lab where a plastic shield (usually used to prevent splatter accidents in chem labs) around the bomb was hit by the explosion, and the shards caused serious injuries.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 03:25:42 pm
content: thats really interesting, I'm planning on doing something alot more primitive than that.I don't know what critical point even is.So even friction can set off liquid oxygen, but what if its diluted in water, is it less explosive? Cause at 2000 psi I compute im still 90% diluted in water, even tho my calculations could be way off!!! So I better be careful.Im actually "drying" something as well, there is icy cold "mud" (with the magnesium oxide in a milk of cold water) in there and I want to evaporate off all the h2o over time in the presence of a gas (which accellerates crystalization, like an acid.), so I was thinking of vibrating it and somehow transfering to a condenser nearby, but maybe the friction will agitate the oxygen and might blow up...If it turns out risky as hell, I can make magnesium carbonate instead of magnesium oxide and ill be just as happy, and it might be way less dangerous.The carbonous acid counts as 1% when the oxygen-base counts as 10%, ph wise. at the same pressure. But its only my dodgy calculations I'm not sure about any of it.But! If I just use compressed air instead of oxygen, is that alot safer???If I use pure oxygen I can probably get away with way less PSI... so maybe if I use oxygen I should only limit the psi that goes in, to save my skin.So whats more dangerous... 2000 psi co2, 2000 psi air - or 200 psi pure oxygen? (cause I think its the same effect on crystalization.)At 200 psi, its probably 1% liquid oxygen (only by my dodgy calculations tho...), I wonder if thats not as explosive?

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: March 10, 2022, 04:05:16 pm
content: Quote from: Capernicus on March 10, 2022, 02:24:05 pmYes, I regularly fill the cylinder when I empty it welding.However, I do follow all the security procedures and that's one of the reasons I'm still alive.Quote from: Capernicus on March 10, 2022, 03:25:42 pmForget for a moment the gas.Besides oxygen being very dangerous, the other point that we are trying to make is that *all* pressurized containers store a lot of energy no matter what the gas inside. And 200psi is a lot, it can really maim you.

author: SeanB
author_rank: Super Contributor
timestamp: March 10, 2022, 04:58:15 pm
content: I had the training on LOX and high pressure oxygen, and even things like having shoes with polish on them can be flammable. We had a special dispensation not to polish our working shoes, because of the risk of the wax catching fire. In the military, where shoe polishing is considered an art, and your shoes are expected to be a mirror like gloss at all times, but us Instrument fitters were exempt. We did have fun with that rule.But remember that oxygen, even at 1 atmosphere, is very much going to support combustion, even for things they you would not consider flammable, like paints, most plastics (including PTFE, even if half the oxygen equipment uses it for seals and piping), aluminium, once the oxide layer is breached, and even stainless steel. Put it under pressure and many more things will burn, such as that little burr scraped off the surface when putting the lid on, and definitely any cheap unknown seal material used in the lid, likely some form of silicone rubber or EPDM or nitrile rubber, it will likely either smoulder or simply burn, and once there is a hole through the gas flow will turn the burning material into a flame jet.We had separate armoured rooms where the oxygen equipment was kept, with blast proof doors, and with clear access so that the blast would not damage much more than the room. Inside the lighting was all heavily armoured, liquid tight IP68 rated Pratley EEX rated boxes, lamp enclosures, and with the power switch outside the room. The filling of high pressure cylinders was an entirely separate section, with a prefab hut for the operation, so the blast would not be fatal for too many other than those inside, and the cylinders were always filled with no people in the room, and all outside by the vapouriser, behind it's own blast wall.Pure oxidiser gases are dangerous. Oxygen, flourine, chlorine and bromine, because they all support vigorous combustion and are common, and either gas or liquid depending on temperature and pressure, and are a relatively common material to get in pure state. iodine is also dangerous, but is not as reactive, and the others in the 2 colums are either solid, or are simply going to kill you for other reasons.That 304 stainless series thin wall pot is really only rated for air, or water, at no more than 4 bar, as it will want to turn to a ball, and being thin wall it likely is just about capable of handling 6 bar before splitting along the side, from all the cold work that has been done shaping it. 1000 cycles of pressure to 4 bar likely will see it failing.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 05:06:20 pm
content: Quote from: SeanB on March 10, 2022, 04:58:15 pmYeh would definitely take more than a pepsi bottle, but u probably want a blast shield around that thing with a big heavy concrete lid on it under the surface of the ground.Who'd want to trust the engineers involved, best to be safe and sure.--- and--- only use 200 millilitres of it, and concrete the rest of the volume up inside. Then see if the bastard can hit 20,000 hehe (jk, i think im only going to use 200.)

author: TimFox
author_rank: Super Contributor
timestamp: March 10, 2022, 05:07:58 pm
content: "thats really interesting, I'm planning on doing something alot more primitive than that.I don't know what critical point even is."An apocryphal statement attributed to Fats Waller: "...if you don't know by now, don't mess with it!"Have you looked at the document that Leica linked in the link I sent you above?

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 05:19:45 pm
content: Yes it was amazing, but I didn't quite understand.They had some good ball park figures there, I need to rebudget everything, theres more I need to know, definitely, so I'm going to put the project off for a while yet for anything high pressure.I'm just going to set up a little 100psi system (but with pure oxygen) and see if I get some cementing to happen. If it turns out I'm completely off with everything I'll go for more reading. I'm kinda a little restless at the moment, I want to see something happen with what I know now.May just all fall apart in my hands, wont agglomerate at all.(heres a vid of me with some gypsum chalk, I did it in a vibrating crock pot, and it was pretty tough, but yes I snapped it...)I think you can actually have a "crock of shit" and it makes the poo go hard! with slow high temperature evaporation! =) hehe

author: IanB
author_rank: Super Contributor
timestamp: March 10, 2022, 06:00:15 pm
content: Quote from: Capernicus on March 10, 2022, 03:25:42 pmEverything you are writing is incorrect.The presence of a gas does not accelerate crystallization.Acids do not accelerate crystallization.Oxygen is not diluted by water, because oxygen does not significantly dissolve in water.Oxygen is not an acid, nor is it a base.You suddenly brought in carbonous acid out of nowhere. Where did you get that from?Carbonous acid does not count as 1%, pH wise. That sentence has no meaning.Oxygen-base is meaningless and does not exist.Oxygen does not affect pH as it is neither an acid nor a base.Liquid oxygen does not form by increasing pressure, 2000 psi or otherwise.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 06:18:34 pm
content: Yes you are right, I'm not the most wisest chemist at all, All I know is salt disappears in water for some unknown mystery and it all snowballed from there.If you add co2 to water you get a rise in ph, and its linear to pressure. (and a change in ph will increase crystalization.) It makes carbonous acid. (On the internet it calls it carbonic acid, but it isn't. sulphurous acid is when sulphur dioxide is added to water, and it "softens" gypsum.)I don't know for sure, But I figure if you add oxygen it lowers ph. they are both gasses, so I guess all gasses do it. I may be wrong.Carbonous acid (with CO2) "softens" carbonate minerals.Sulphurous acid (with SO2) "softens" sulphate minerals. (like Gypsum.)So If Sulphur and Carbon do it, I'm guessing oxygen does it as well, but I'm also guessing it softens it even more! because its more potent a gas.Then the gas pressure has a briquetting action on the softened mineral. (I put it in a special collapsing mould, that allows a few millimetre's of shrinkage.) So it softens it, then it pushes it together in a scintering type action, both with the same mechanism, compressed gas.Thats the idea, I told you its quite simple and primitive. I know!!! it happens with sulphur dioxide and carbon dioxide, but its only weak, yes, But with oxygen it may be stronger at the same pressure, but its a mystery I have to try to find out.Its a stab in the dark of a generalization, might be true, might not, have to find out.

author: IanB
author_rank: Super Contributor
timestamp: March 10, 2022, 06:32:11 pm
content: Quote from: Capernicus on March 10, 2022, 06:18:34 pmIt dissolves. It will come back again if you evaporate the water.QuoteIt makes carbonic acid. The internet is correct. Carbonous acid is another name for formic acid, which is something else entirely.I don't know what you mean by "softens". Gypsum is a mineral. It is hard. Nothing "softens" it.QuoteOxygen does not lower pH, because oxygen is neutral.All gases are different, so different gases do different things. You cannot generalize like that.QuoteCarbonic acid can dissolve carbonates like limestone. It doesn't soften them. They remain hard until they dissolve, and then they are gone.QuoteSulphur and carbon are solids. Oxygen is a gas."More potent a gas" does not mean anything in this context.QuoteNot sure what you are trying to say here.QuoteThere is no softening. That is not a thing.

author: KaneTW
author_rank: Frequent Contributor
timestamp: March 10, 2022, 06:33:55 pm
content: Just... shut up. Stop. Don't do this, or anything related to chemistry, or elevated pressures, or electricity for that matter, until you have a firm grasp of the basics.

author: TimFox
author_rank: Super Contributor
timestamp: March 10, 2022, 06:38:26 pm
content: Generalizations about chemistry usually require looking at the Periodic Table.Oxygen and carbon are in different columns. Sulfur is under oxygen, but sulfur dioxide is different from molecular oxygen.Does dissolved oxygen affect pH? Once again, Google gives us this result:https://atlas-scientific.com/blog/does-dissolved-oxygen-affect-ph/I suggest that you do some simple research before asserting: "I don't know for sure, But I figure if you add oxygen it lowers ph. they are both gasses, so I guess all gasses do it. I may be wrong"When I was young, I read a bad translation of Verne's "20,000 Leagues Under the Sea" that kept referring to "carbonic acid" when it meant gaseous CO2in the local atmosphere, which confused me since I had just read a children's book about medical disinfectant and thought it meant "carbolic acid", a quite different chemical.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 06:41:12 pm
content: Quote from: IanB on March 10, 2022, 06:32:11 pmThey come back just like salt does, at the bottom of the pot when the acids all fumed off. (Into co2) If they just "disappear and not come back" Where did they go to?Its how to make a salt, with a metal and an acid. And chalk is another kind of salt.Seems funny, but I dont trust wikipedia for anything much at all, I find other sources way better.But like I said, I could be wrong about this whole thing, I dont mind if I am. I'm just prooving things myself cause I trust bugger all around me!!You might be able to inject hydrogen into water as well, and it goes acidic. (but I think oxygen stops it turning into a hydroxide. but I could be wrong easily.)

author: TimFox
author_rank: Super Contributor
timestamp: March 10, 2022, 06:51:37 pm
content: I use Google and Wikipedia to find quickly a treatment that others can look at.I have lots of textbooks from my student days, but they are hard to cite.Not looking anywhere at all, even in "quaint and curious volumes of forgotten lore" when dealing with chemistry and other obscure topics, is not useful.

author: IanB
author_rank: Super Contributor
timestamp: March 10, 2022, 07:23:08 pm
content: Quote from: Capernicus on March 10, 2022, 06:41:12 pmThis is correct. The dissolved solids come back if you evaporate the water (but as the bicarbonate, not the carbonate). The CO2 will not fume off unless you make it very hot.QuoteThis is correct.QuoteWikipedia has its faults, but is is mostly correct about most things.QuoteThis is not correct. Hydrogen gas, like oxygen gas, is neutral. If you dissolve it in water it does not change the pH.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 07:29:56 pm
content: Quote from: IanB on March 10, 2022, 07:23:08 pmI'm yet to see the litmus test on it!!!

author: PaulAm
author_rank: Frequent Contributor
timestamp: March 10, 2022, 07:30:13 pm
content: QuoteGawd, this is so far off any basic understanding of chemistry as to be beyond the pale.Well, as suggested earlier, livestream the procedures, eventually you will get to a teaching moment.

author: LaserSteve
author_rank: Super Contributor
timestamp: March 10, 2022, 07:31:21 pm
content: OK< Link is incredibly disturbing and gross.This is what happens when things go wrong with oxidizers and pressure vessels:https://youtu.be/rUKcHe0-m_I?t=302His parents permitted the use of the pictures in the safety film. May he rest in Peace.I still wonder if OP is trolling us.If you have no clue what your doing, it is time to leave this experiment alone.Steve

author: TimFox
author_rank: Super Contributor
timestamp: March 10, 2022, 07:54:56 pm
content: A typical way to make an acidic liquid is to take a gas such as HCl and dissolve it in water.The HCl molecules dissociate into two ions: H+and Cl-. The H+ions are what make the result acidic.Now, neither H2nor O2molecules can dissociate into two ions: H+is always a positive ion, and O-is always a negative ion.H2O, of course, can dissociate into H+and OH-, which gives pure water its finite pH value (a logarithmic measure of the hydrogen ion concentration in the liquid).

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 09:12:10 pm
content: Yes, I think that Hydrogen and oxygen dont have much of an effect on water now.I looked up "Gas solubility in water" and got a bit of a shock, oxygen and hydrogen were the lowest, maybe somethng is going on tho, because they are a slightly soluable. they arent totally neutral or they wouldnt mix at all... but very little effect for psi...But sulphur dioxide has a huge effect! the water just keeps sucking it up! makes u wonder how much sulphur dioxideis in all water. So it means I'm best sticking with gypsum if I do this, put 100 psis worth in a pepsi bottle and ill probably havea 175% concentration! so that might make anhydrite!With carbon dioxide at the same psi level its only 2% concentrated and its more affected by dibasity... (i still have a theory going for the that one thats not dead yet.) Id have to pump that up to 2000 psi, then get affected by the dibasity to even get half diluted...So the crystalization potential for sulphates is alot higher than carbonates.With carbonates your better off with just proper acid, not just dissolved gas. I got this interesting idea of getting the mud (be it mag carb or copper carb - in the art mould) and then zapping it in from a soluable rock solution through a membrane. (Making the acid how I was shown on the net.)But if its oxide or hydroxide, Ive got no idea, but maybe it just takes a shit load of psi with oxygen, but its more than I could ever produce without blowing myself up... if u look at the solubility, its very low. - but... that means its not doing nothing entirely.

author: jpanhalt
author_rank: Super Contributor
timestamp: March 10, 2022, 09:15:33 pm
content: Yes, he's a troll.

author: jpanhalt
author_rank: Super Contributor
timestamp: March 10, 2022, 09:50:39 pm
content: Quote from: pardo-bsso on March 10, 2022, 01:58:17 pmNot quite, but a good point anyway. Use the periodic table. Chlorine (3rd row) is slightly more electronegative than oxygen (second row).* That leads to some interesting combinations. But, fluorine is more electronegative than both. Thus, water "burns" in fluorine.However, fluorine is such a "rare bird" and reactive that ordinary organic chemists didn't learn much about it when I was in school, omitting UF6, of course. We were such nerds that when someone in the the mass spec room dropped and broke a vial of UF6, we were taking a final exam and refused to evacuate, until were forced to under promises that we could finish.*Electronegativity (ability to oxidize other substances) increases left to right and decreases top to bottom.

author: jpanhalt
author_rank: Super Contributor
timestamp: March 10, 2022, 09:51:57 pm
content: Quote from: Capernicus on March 10, 2022, 09:47:48 pmTroll.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 10, 2022, 10:19:55 pm
content: Hey u trapped my joke like gas in a liquid, i dont think stuffing acid down peoples oesophagus's is the right thing to do, no matter who they are.Thats actually one way to make it too!!

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 11, 2022, 01:09:05 am
content: proof of concept->

author: MK14
author_rank: Super Contributor
timestamp: March 11, 2022, 07:30:34 am
content: Quote from: jpanhalt on March 10, 2022, 09:15:33 pmThat would seem to contradict, the various, somewhat related to this thread topic, videos, they have spent time and effort making. Because if they were trolling, why would they make all those somewhat or fully crazy videos.Channel link is from here:EDIT: Changed quote, is NOT the original quote anymore, see below for details.Quote from: Capernicus on March 10, 2022, 05:19:45 pmDeleted link...............I don't want to be needlessly rude about the OP. But, they don't seem to be performing 'experiments', with the safest, professional lab equipment or have any real proper scientific knowledge/understanding.Or if they are a very high end, highly experienced and talented Chemistry Professor, who has written hundreds of well received papers. They are an absolute genius at making videos which almost 100% hide those talents, experience, and abilities from the viewers.Also, what is it with all the highly obnoxious hate videos, bordering on terrorist tendencies ?On their video channel. I hope they are NOT trying to use this thread, to learn how to make some kind of bomb or something ?At least one of their videos seems to delight on showing someone being killed in real life, I thought such videos and channels are banned on youtube ?I get the impression (but could be wrong), that some kind of substance abuse, is causing the OP (and hence their video channel), issues. There seem to be signs of it, in some of their videos. They also seem to sound rather rambling and 'out of it', making it rather difficult to follow or understand their videos.tl;drIs this guy safe ?(I'm NOT Australian. So it makes it harder for me to judge the person from experience. Also, I'm not sure how legal or not, the substance(s) they seem to be using and how legal their apparent bordering on terrorist like youtube channel's political views and/or potentially disgusting videos, are illegal or legal in Australia).

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 11, 2022, 08:02:27 am
content: Quote from: MK14 on March 11, 2022, 07:30:34 amIll be ok, I keep everything legit, thats why I dont mind ppl seeing my videos.Its all above the board, and I've got excuses for it all.Thats all my lazy uploads, I dont really monitor it I just put any old crap up, its all interesting to me.As you can see im quite a productive musician, programmer, artist. Whats criminal about that? Its the opposite.Just look up stinky **** and ull see videos by other guys similar to me.at least im not jocking off to "inter-racial" porn everyday, those guys are the real criminals in my view.

author: MK14
author_rank: Super Contributor
timestamp: March 11, 2022, 08:42:14 am
content: Quote from: Capernicus on March 11, 2022, 08:02:27 amExample:EDIT: Deleted Channel link, as apparently requested here:https://www.eevblog.com/forum/chat/heres-a-gas-pressure-vessel-can-i-get-some-advice/msg4056190/#msg4056190Warning, viewer discretion advised. Apparently rambles on about very extreme political views, seeming to mention about killing/exterminating, some type(s) of people, at around the 1 minute mark. I find it difficult to understand, precisely what you are on about, but the gist of it, seems bad/extreme.

author: Capernicus
author_rank: Frequent Contributor
timestamp: March 11, 2022, 09:16:25 am
content: Now this is just another naive observation, pay little thought to it necessarily.I wonder about you guys, that once u start swaying from honesty with posts you make, it becomes an invarience that one cant even really notice anymore, and then it becomes equally as true, for whatever reason.Thats why im always relatively careful here. (Even tho it may not seem it to you guys, I realize.) Because its all a big hidden mask, and everyone I'm feeling now is hiding possibly 90% of things they actually know.So Its all a little disturbing to me, as I realize all these things outside of just maths and making things, that I never payed much attention to before. About how life... doesnt work... only works if u try to make it work, or see it in some way it works, theres much conflict.And its all sorts of crud u wish wasnt there cause it would make things simpler, but then maybe things are too simple? I just need to switch off, and just get to back to what I'm good at, and just make things, NOT sell them, NOT try to get people to like them, NOT to teach anything, And to get Nothing but the thing I make for it! Forget politics, forget all the pollution, forget all the pain and misery, forget all the shitty wars, theres just nothing you can do about it, and unless its just outside your door who gives a shit about it.I do respect ppl here, and if you know better than me about a great many things, I wouldn't be suprised!

author: MK14
author_rank: Super Contributor
timestamp: March 11, 2022, 01:47:29 pm
content: Quote from: Capernicus on March 11, 2022, 09:16:25 amOK.What EXACTLY are you trying to make, at a high level. I.e. what problem are you trying to solve ?As far as I can tell, your details seem rather sketchy. Rather than describe what you think is the solution(s) to some goal you have in mind. What exactly is the GOAL here ?

author: LaserSteve
author_rank: Super Contributor
timestamp: March 11, 2022, 02:40:18 pm
content: After doing the US standard vessel spreadsheet, at 4 Bar his pressure vessel in the original post has 1.25 KJ of potential energy, from presurization alone.Steve

author: Monkeh
author_rank: Super Contributor
timestamp: March 11, 2022, 05:00:43 pm
content: Quote from: MK14 on March 11, 2022, 07:30:34 amCan we not keep sharing the link to the racist bigotry channel?

author: MK14
author_rank: Super Contributor
timestamp: March 11, 2022, 08:19:18 pm
content: Quote from: Monkeh on March 11, 2022, 05:00:43 pmOk.I think I've deleted them all, now.

author: Gyro
author_rank: Super Contributor
timestamp: March 11, 2022, 09:57:33 pm
content: Quote from: Monkeh on March 11, 2022, 05:00:43 pmAgreed, I've deleted my link in reply #46.@Monkeh: You quoted my post, you might want to do the same.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: March 12, 2022, 02:44:54 am
content: While I agree with all of the previous warnings against high pressure oxygen (which have possibly been understated), I want to add that any really high pressure gas or fluid has serious dangers quite aside from any chemistry involved. Gases usually more so because leaks don't cause the pressure to drop rapidly as it does with relatively uncompressible fluids.Small leaks can inject gas through the skin centimeters or more from the leak. A careless assembly or disassembly can launch parts like a cannon. And broken gas lines become high speed cutting snakes whipping around at unbelievable velocities.Any time you concentrate energy it opens up many chances for it to get away in unplanned ways, and those almost always turn out to be dangerous. And while you can say they aren't that dangerous because you or someone you are aware of has survived one of these situations, that is akin to saying Russian roulette isn't very dangerous. It is true that you have to play Russian roulette multiple times before your odds of dying are truly high, but most sane folk consider even one trial too risky.

author: 0culus
author_rank: Super Contributor
timestamp: March 12, 2022, 03:10:54 am
content: I read through this thread, and all I can say is WTAF.

author: Cerebus
author_rank: Super Contributor
timestamp: March 12, 2022, 04:18:49 am
content: Quote from: CatalinaWOW on March 12, 2022, 02:44:54 amAnyone who doesn't "get" how serious this can be should google "degloving injury" and look at the pictures. Don't do it within two hours of a meal, either before or after, unless you're the kind of person who can happily sit through lunch with a bunch of nurses discussing a particularly messy "day at the office". Degloving injuries are at the 'nice' end of what can go wrong when high pressure gas or fluid encounters soft, yielding flesh.