Regulators Depth Limitations

[tbone1004]

Halocline, BS there is a perfectly practical reason for using unbalanced piston first stages, they cost basically nothing.... The one listed above is similar to the MK2+ being balanced and straight though, I prefer the straight through's for O2 use because there isn't a 90* bend and other than the brief history of the Poseidon MK3 for O2 I don't know of any diaphragms that were made like that in recent history. I didn't get a MK2 because of service kits for them, so the one I linked, or any other simple piston is certainly going to work perfectly well for any O2 use.

Agreed on buying used since they are going to have to be O2 cleaned.

Used Genesis Regulator - Just Rebuilt/Oxygen Clean - Northeast Scuba Supply Store
$100, already O2 clean, only downside is it is yoke, but for an O2 reg, it doesn't particularly matter.
NESS Stage Bottle Regulator - Yoke - Northeast Scuba Supply Store
$160, again yoke, but O2 clean with a green hose and cap, how do you argue with prices like that?

 

[halocline]

Halocline, BS there is a perfectly practical reason for using unbalanced piston first stages, they cost basically nothing....

To clarify, I meant that there is no specific reason that unbalanced 1st stages work better for O2 than balanced 1st stages, that was what the OP had asked several posts back. If the OP owns a balanced 1st stage, (titan) there is no reason it will not work fine for O2 as long as it's O2 cleaned.

A balanced regulator that one already owns is less expensive than buying an unbalanced regulator.

 

[Remy B.]

Thanks for all your posts guys, really appreciated.

 

[RJP]

You should be fine with the Titan. For me the most important thing is the confidence that I have in any particular brand. When you are deep, confidence is more important than someone's technical specifications. Be safe and enjoy.

Wait... did you just say what I think you said?

 

[Peter69_56]

You don't have the triangle of fire, I'm talking about a regulator that has been prep, with the right Seals and Lubricants for high O2 application, and there is no heat source, a pinch point where compressed gas passes thru a lower pressure chamber/area actually have a cooling effect called the JT or John Thompson effect, the oxygen will not Chemically react with the rubber of the hose to my knowledge, and your break pressure on your regulator at surface I will guess is 1.5 to 2 Atmospheres or 21.5 to 29.2 Psi Absolute, so pressure does not come in factor here, you have two things missing in the triangle of fire in this case.

Remy

I just checked my gas blenders handbook and thought you might appreciate the information in it;

Sources of ignition with high levels of oxygen

Isentropic (adiabatic) compression, where rapid temperature rise causes ignition of contaminants or components (this can happen when an empty regulator set is turned on quickly, and has contamination from standard air fills [not nitrox clean air] and is then used for high levels of oxygen without being re-cleaned)

High velocity particle impingement, where metal or other particles spark as they collide with bends, fittings.

Buildup of condensed hydrocarbons until there is sufficient to ignite

Localised frictional heating caused by flow impediment of restrictions, reducers and tight bends, particularly those of more than 90 degrees.

For you (as others have posted), the risk is using a nice clean O2 serviced regulator on a "Normal" tank of air (or worse a contaminated tank from a dodgy LDS), and then without being cleaned, then used on high O2 gas. If you want to use O2 regs with normal air, then they must be cleaned prior to use with high O2. If you wish to use your regs for all gas from 21% to 100% oxygen then you should only use air that is to the standard for Nitrox use. In this way all your gas is "clean" thus the regulator set is not contaminated (in theory).

Hence that's why I only use my own gas in my tanks. I never have them filled at any LDS unless they can provide Nitrox quality air, as all my tanks and regulators are O2 cleaned (as I do it myself).

So I guess the simple answer you were seeking is, if you have the chance of having fills which you cannot guarantee are Nitrox quality air, then you should have a reg set for air diving and Nitrox to 40%, and a oxygen clean set for 41% to 100% (usually for deco). In this way you have done all you can to follow the standard and minimise your risk. I have a recreational set for air/Nitrox to 40%, tech set for back gas (but clean), 2 deco sets I use to about 60%, and special set for 100%. Its all probably overboard but as I need most of the reg sets anyway, I prefer to ensure that the higher the O2 level, the more specific they are for the purpose. I do have 2 sets I only use on air, they are not specifically cleaned or serviced for Nitrox and so can be use on anyones air cylinder.

Hope this helps your understanding.

 

[oldschoolto]

In a world of compromise... Some men DON'T..

Jim....

Ad for H&K firearms... Picture of navy seal with a MP-5

 

[tbone1004]

To clarify, I meant that there is no specific reason that unbalanced 1st stages work better for O2 than balanced 1st stages, that was what the OP had asked several posts back. If the OP owns a balanced 1st stage, (titan) there is no reason it will not work fine for O2 as long as it's O2 cleaned.

A balanced regulator that one already owns is less expensive than buying an unbalanced regulator.

I know what you meant, was just pulling your leg :-D

 

[Remy B.]

Remy

I just checked my gas blenders handbook and thought you might appreciate the information in it;

Sources of ignition with high levels of oxygen

Isentropic (adiabatic) compression, where rapid temperature rise causes ignition of contaminants or components (this can happen when an empty regulator set is turned on quickly, and has contamination from standard air fills [not nitrox clean air] and is then used for high levels of oxygen without being re-cleaned)

High velocity particle impingement, where metal or other particles spark as they collide with bends, fittings.

Buildup of condensed hydrocarbons until there is sufficient to ignite

Localised frictional heating caused by flow impediment of restrictions, reducers and tight bends, particularly those of more than 90 degrees.

For you (as others have posted), the risk is using a nice clean O2 serviced regulator on a "Normal" tank of air (or worse a contaminated tank from a dodgy LDS), and then without being cleaned, then used on high O2 gas. If you want to use O2 regs with normal air, then they must be cleaned prior to use with high O2. If you wish to use your regs for all gas from 21% to 100% oxygen then you should only use air that is to the standard for Nitrox use. In this way all your gas is "clean" thus the regulator set is not contaminated (in theory).

Hence that's why I only use my own gas in my tanks. I never have them filled at any LDS unless they can provide Nitrox quality air, as all my tanks and regulators are O2 cleaned (as I do it myself).

So I guess the simple answer you were seeking is, if you have the chance of having fills which you cannot guarantee are Nitrox quality air, then you should have a reg set for air diving and Nitrox to 40%, and a oxygen clean set for 41% to 100% (usually for deco). In this way you have done all you can to follow the standard and minimise your risk. I have a recreational set for air/Nitrox to 40%, tech set for back gas (but clean), 2 deco sets I use to about 60%, and special set for 100%. Its all probably overboard but as I need most of the reg sets anyway, I prefer to ensure that the higher the O2 level, the more specific they are for the purpose. I do have 2 sets I only use on air, they are not specifically cleaned or serviced for Nitrox and so can be use on anyones air cylinder.

Hope this helps your understanding.

yes I have some of that information, the biggest point is the amount of pressure and the time for the chemical reaction or the heat source to complete the triangle of fire.

Pressure and time played in as at higher pressure more risk, that is why it is so dangerus in the cylnder more than in the regulator.

the distance from the nosle of the valve to the 1st stage is very small, then it is made of brass, that is very unlikely to be determinant of friction, that is why brass tools are used in hazard enviroments because it takes away the heat/friction in a very big %, in the case of diving if you follow your procedures right, and you press your 2nd stage before you slowly open your tank valve, the velocity is very small and the risk very low, then comes in the suspended hydrocarbons solvents or chemical reactives like oils, amount plays big here, how much is to much, that is the threshold we don't know and is not worth to find out either, but I believe it have to be very nasty regulator so there is enough time to chemically react with the high O2, then in the case that your 1st stage is contaminated the shear amount of pressure going thru the small passages will probably wash away what is in it, then comes the expantion portion that is where your gas is regulated to a lower pressure thru a controller orifice gate/port, then you lose that big pressure from 3000psi to probably 20+ Psi Absolute at surface, if your hose between your 1st stage and 2nd stage is very nasty with sticky oil on the walls, if you leave that 100% O2 long enough "Time" to chemically react then you will have a blue flame melting your scuba system.

You are 100% right by following the standards you minimize the risk, in the case of one upset of the triangle of fire, and in the standards is all about minimise the risk from making a good day turn in to a very bad one.

My comment of the regulator set O2 clean been overrated, is do to the fact that it plays so much factors in order to something go bad, once you use a O2 clean regulator with a air bottle that maybe is contaminated, but I believe it have to be a good quantity of contamination, how much is too much, don't know and will not try to find out either, so I will keep a O2 clean reg for that purposee only, and hope for the coming future that if I use 50% O2 or higher for Deco gas that the other % of air is clean.

I don't know what the certified O2 cleanTechnician inspect precisly, I wonder if they pay attention of what is in the hose or how clean it is.

Some standards say that any thing higher than 23%O2 was considered dangerus and have to be treated as 100%.

---------- Post added April 20th, 2015 at 06:03 PM ----------

If you have a video from that test of the high % O2 bottle making a torch out of it, let me know so I can PM you my e-mail address.

---------- Post added April 20th, 2015 at 06:12 PM ----------

I wish I had the money to have my own compressor and membrane station, so I know how the state of clean the system is.

 

[Basking Ridge Diver]

BTW - Fire Triangle has been updated for several years now as a Tetrahedron... As a volunteer fireman I had to point that out.
Catawba Valley Community College

 

[Remy B.]

BTW - Fire Triangle has been updated for several years now as a Tetrahedron... As a volunteer fireman I had to point that out.
Catawba Valley Community College

Yes you are correct, is time and reactivity not in that Tetrahedron ?, we still use the old triangle method to keep it simple, I remember seeing it in class room but that has been a long time ago

---------- Post added April 20th, 2015 at 06:27 PM ----------

Now that I see your link, actually there is a more complicated shape than that, there is, that depends on the reactive substance, amount of time, amount of pressure per each combination of substances in that fire equation.