Scuba Tech Tip: How Is Nitrox Made? - S08E21

[Music] hi guys Alec Pierce kuba tek-tips I'm gonna talk quickly today because this is a fairly technical topic and there's about a bit of information I'm gonna try to simplify it how do they make night trucks when you go into a assuming your nitrox diagram you want to use night trucks just another whole topic entirely but assuming you are and you're going to your dive store and you want to you say I want some night rocks give me a mix 32% where's it come from you know they don't they don't buy it it doesn't get shipped in them boxes and you know doesn't work that way they have to make the networks there's some method they have to have to get that 32% nitrox and then get it into your tank how do they do that well first of all I'm explained is a variety of ways and no particular way is the best it depends on many many circumcision how much nitrox they sell how how easy it is for them to get the net trucks it's different suppliers of the different gases required mainly oxygen how much money they're prepared to invest in their night trucks supply how technically inclined are the people at the dive store and so on there's many many factors to consider when a dive store owner decides he wants to start supplying nitrox for his divers but let's deal with a couple of them okay first of all they're by far the easiest method is to for the dive store to buy pre bottled night rocks so you see you can buy any gas you can buy carbon dioxide or nitrogen or or acetylene or oxygen any gas you want from a gas manufacturer this is a big plant and that's what they do they get gas in or they make gas they put in the big tanks and then they sell it so if I was a dive tour owner and I did not want to make a big investment I had just a couple of nitrox customers I wanted a quick easy inexpensive way to supply my customers with nitrox I would call up the gas supplier and I would say send me over two bottles of 32 percent that's what he would do so I would have two bottles two big bottles like this 450 some my cubic feet whatever whatever it happens to be and of nitrox and if you come into the store and said hey Bill my name is Alec but it's pretend here hey Bill I wanted a 32% nitrox you let me take your tank I've connected to this tank open the two valves fill it 32 percent out you go and and charge it for it in the way you go everybody's happy so pre-mixed bottles that's one way to get your nytruck downside first of all it's not going to be inexpensive this is probably the most expensive way to to buy nitrox so the dice toner won't make as much money but a game remember the factors he doesn't sell very much only has a few customers doesn't want a big investment so he has saved on that side he loses on this side also there are some other practical limitations he is limited in the fields that he can give by the pressure of the supply bottles he may have to get a booster what's called a booster usually by a company called Haskell that's the biggest name on scuba and a booster is simply a device that takes air from this tank puts it into that tank but it's tricky because you can take air from this tank and this tank is that 2,000 psi and it can put air that air into this tank at 3,000 psi how does it do that well that's why it's called a booster a booster can take the pressure out of here boost the pressure put it into there boosters are not inexpensive five thousand dollars roughly for a small booster a large high capacity booster to be a lot more than that so they may have to make an investment anyway but quickest cheapest easiest way to get on that trucks mix is to buy a big tank of it a big bottle of it and then figure scuba tanks from it the next probably the second most common method if not the most common method for for making nitrox is what's called partial pressure method the partial pressure method and that's very simply a method by which that after our owner calculates what the pressure of each gas in the mixture is needed to be equal 32% and this goes back to dalton's law of partial pressures now you may or may not have learned this in your scuba quest when I took my scuba course back in 1960 we had to know dalton's law of partial pressures we had to be able to repeat the law we had be able to spell his name and know his date of birth and date of death no it's great of course but anyway you don't even need to learn that information anymore all you need to know for the purpose of this is that if you have a mixture of two gases oxygen and nitrogen shall we say and the oxygen forms 30% and the nitrogen obviously 70% have that then the pressure the total pressure that's a 3,000 psi the total pressure of 3000 psi is split between the two gases and it's the same proportion so the oxygen which is 30 percent by volume also is 30 percent of the pressure the nitrogen which is 70% the remaining volume also gives 70 percent of the pressure you see so the partial pressures of each of the gases in the mixture always totals the total pressure don't worry about if you didn't completely understand that but what it means is a dive toner can take your tank and you can say to him I want to nitrox mix of 32% the dr. owner will go to a little calculator and he will be able to quickly determine how much oxygen to put into your tank and he'll do that so his computer will tell him to put in 462 psi of oxygen say he'll take his oxygen cylinder and connected to your scuba tank and you put 462 psi of pure oxygen into your cylinder then he will fill the rest of the cylinder was regular air and his little computer the little computer program tells him if you put in 462 psi of pure oxygen and then the rest up to 3,000 is with normal atmospheric air you will end up with a mixture which is 32% oxygen that's what you wanted 32% nitrox mix and he can do that very simply it really is quite simple again at some time some of the practical issues might be that he may have an oxygen supply bottle that is only at 500 psi and he has to put in a hundred psi is not able to do that might be difficult again with other booster or some other special equipment so using partial pressure is not perfect although it is relatively inexpensive doesn't require a big investment in materials or machinery it does have one downside since when using the partial pressure method the dye store owner is using pure oxygen so pure oxygen is going into your cylinder then your cylinder and the valve and everything else that might be in contact with that pure oxygen has to be cleaned it has to be what's called oxygen clean not on oxygen ready not nitrox ready oxygen clean to put pure oxygen into a valve in a cylinder that does not oxygen clean can lead to a serious problem potentially a fire potentially an explosion so there are some downsides to that system as well it's quite common however because of its inexpensive alright let's talk about another very common system and this method is commonly called to stick now when I say the stick I'm actually using a brand name the stick is a special device that was developed by by the scuba industry by scuba divers to produce night rocks let me explain what it is very simply what this system there's a fairly large investment in initial cost but the beauty of the stick using the stick for producing night rocks is that you can produce night rocks indefinitely you can just keep making it as much as you want it's quick and easy and very safe in fact you don't even really need to have oxygen clean cylinders and equipment because the matrix that you're using is now an oxygen it's enriched air there's no 100% oxygen anytime anytime the oxygen content in air gets above about 40% then the likelihood of problems because the oxygen content is high gets higher we're using the stick if you want a 28 or 30 32 or 36 percent not and nitrox mix that's what comes out of the fill whip and goes into your tank so there's some benefit there you're not using pure oxygen in the divers tank so how does it work well really is very simple you use a stick Oh Kevin I want you look up here that's a stick a black thing it doesn't look all that impressive does it it looks like a piece of ABS with a couple of plumbing fittings on it that's exactly what it is that's exactly what it is now not quite that simple most dive stores well some do try to make it themselves some most eye stores now would purchase a stick a commercially made stick you'll notice at the very top Kevin there's a what looks to be an air filter and that actually is an air inlet air gets sucked in there at the very top and partway now you'll see a plastic line going in to the stick into that black stick let me see that and then right here Kevin you see this device right here that's a sensor that's specifically an oxygen sensor so you have air coming in the top you have that line which I'll tell you right now is an oxygen line yes that puts in pure oxygen so air comes in pure oxygen goes in and they mix inside the stick that's right and then it has the mixture which now is oxygen and air gets down to here you can measure it make sure it's exactly what you want then it comes down into this corrugated tube and into your compressor so you simply take the compressor hook it up to the divers tank start the compressor turn on the oxygen tank and set it based on the reading of the oxygen coming out of the stick which is right here and when this reading hits 32 you open the divers tank and fill it with 32 percent now I have simplified the process it's not quite that simple but it's pretty close you all you have to do now is monitor and make sure that the mixture being produced by the air and oxygen coming in through the stick is actually 32 percent at this point from there on it simply goes into the compressor 32 percent nitrox gets compressed and goes into the divers tank that make it sound very simple what's the downside to the stick I've told you the upside quick easy high volume low maintenance what's the downside well you got to buy a fair bit of equipment first of all the stick they're not inexpensive but they're not cheap either not normally we're a diver buy a stick on his own you also have to have a steady supply of pure oxygen you have to have a method to control that oxygen here we're measuring the oxygen level but we have to control it suppose this says 26 and we want 30 have to change it don't we take a look over there Kevin and you can see in the corner the oxygen bottle with the green knob gauges one gauge shows how much oxygen is in that tank the other gauge shows the pressure of the oxygen coming out of the tank that's controlled with a grip big green knob it's actually a regulator just like your tank regulator and there's another little knob over there it's a needle valve and with that needle valve you can very precisely control the amount of oxygen going into the stick and getting mixed with the air how you know where you have the right amount all right here watch right here when this hits 32 you're mixing the right amount of oxygen time to start filling the divers tank I make it sound simple it actually is pretty simple once the system is set up other expenses though it's a compressor yeah you're putting in enriched air you're putting in a higher level of oxygen so for safety's sake this compressor has to be oxygen ready as well ready to pump nitrix if you have a normal compressor which is what it's a big pump then you have to have a specialty cleaned you have to be using synthetic oil normal oil which is commonly used in dinosaur compressors based on fossil fuels are much more likely to be a problem if you're using nitrox enriched air you have to have synthetic oil if you're using normal all you have to change it to synthetic oil which involves a bit of bitter work - cleaning new oil running changed again new on the machine yourself has to be specially cleaned so that every bit and pcenter there's no carbon anything else to cause any problems and then again normally you would have to have a booster a booster pump one of those haskell pumps that i mentioned earlier so in total mm-hmm you're probably looking at an investment of about five to ten thousand dollars at least in order to put in the system like this with the stick compressor booster and oxygen not a whole lot of money if you're selling a lot of nitrox but it does require that bit of an investment again not something a diver himself would normally do although it has been done anyway folks there's a little bit of information you've been asking how do they make nitrix and i thought i would take a few minutes i tell you about three methods that are very common in dive stars the next time you go into a dive store whether you're in nitrox diver or not take a look at the fill station itself i see if you don't recognize the type of machinery I've described today and you may be able to say something in television to the Dicer owner oh you're using the stick that's pretty unique I know how that works something like that anyway I hope that was beneficial keep the comments coming we're gonna do some more on nitrox and in in a couple of series coming up how to clean your equipment for now truck shows that need cleaning those does not need cleaning and some more questions like that that I think you might like some of the information okay Sally Pierce I'm off now tech tips talk to you again soon

Channel: Alec Peirce Scuba

Views: 14,511

Rating: 4.968504 out of 5

Keywords: alec, peirce, scuba, tech, tips, tip, underwater, diving, vintage, sea, hunt, remembered, skin, dive, salt, water, fresh, local, shop, At, The, Ranch, service, professional, fun, shark, nitrox, EAN, EANx, enriched, air, daltons, law, partial, pressure, 32%, 36%, oxygen, nitrogen, stick, mix, analyzer, pure, O2, clean, safe, 40%, sensor, compressor, maintenance, AquaSub Scuba Diving Centre, aquasub, aqua, sub, centre, center, pierce, knive

Id: 7TYlcLmlvno

Length: 14min 59sec (899 seconds)

Published: Thu Feb 28 2019