Poseidon Regulators and 100% O2
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It is less of an issue with current poseidons and the integrated OPV on the first stage. The older style with the OPV on the hose, it happened constantly. You didn't have to bump the purge button, just the reg itself. Think of the size of a Poseidon second stage and picture it strapped on a tank, they got bumped a lot.
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Dealing with these before I answer @rsingler
You essentially have 2 options with this, especially if you're diving the salty stuff. Leave the valve open the entire time, or use a different regulator.... Since I cave dive way more than I ocean dive, I don't use Jetstreams for O2 deco because I'm often leaving them alone for hours and valve-on is way too high of a risk. Cyklons work just fine and I actually really like them for deco regs because they tuck into the space around the valve neck and lay really flat.
Your LDS is parroting bad information. The Jetstream and Xstreams IF they are tuned to factory spec breathe just fine at 3ft. If the IP is at "standard" IP range of ~145psi vs 125psi of spec then they are prone to chattering at shallow depths but that not "because of their design" it's because someone didn't rebuild it properly.
Now, to Rob's point. Obviously on the low pressure side we don't have to worry about oxygen compatibility so the question is whether or not the 2960/3960's are suitable for pure O2 use. Unfortunately this may be where there has been marketing decisions regarding the decompression regulator versions of the Xstreams using the MK2/3 first stages where the older units were not necessarily marketed for decompression use once the Xstreams came out. While they certainly have viton kits and people have been using the 2960/3960/etc first stages with 100% decompression and from a design standpoint there is no issue about whether or not the regulators can deal with it, I suspect there is a different underlying issue to why Poseidon hasn't made mention about use with pure oxygen. Machining lubricants used during that period of time were likely not oxygen compatible and it is nearly impossible to truly remove those from the regulator bodies themselves. Similar to how most service technicians no longer keep a set of O2 only tools and just practice standard cleaning procedures on everything, most of the regulator machining is done using all O2 compatible lubricants these days which certainly helps.
Anyone doing service as a business would be off their rocker to certify a regulator for use with oxygen that isn't specifically authorized by the manufacturer, you have no problems saying "this was cleaned following industry standard guidelines for oxygen compatibility and was assembled using oxygen compatible lubricants and where possible, oxygen compatible parts but per the manufacturer is only authorized for use with up to xx% oxygen" because we live in a litigious society, especially the state where Rob lives.
So how can a diver do it? They either have to trust the history of use and their service technician and accept that it's not officially allowed, or they buy a regulator that is specifically authorized to use pure O2.
Let's clarify this to the Jetstream and Xstream models, the Cyklon is standard unbalanced downstream and is no more prone to flooding than anything else.
You essentially have 2 options with this, especially if you're diving the salty stuff. Leave the valve open the entire time, or use a different regulator.... Since I cave dive way more than I ocean dive, I don't use Jetstreams for O2 deco because I'm often leaving them alone for hours and valve-on is way too high of a risk. Cyklons work just fine and I actually really like them for deco regs because they tuck into the space around the valve neck and lay really flat.
The Jetstream and Xstream being upstream require intermediate pressure to seal. If the valve is off then they can flood but they flood back from the second stage which is different than atomic.
Your LDS is parroting bad information. The Jetstream and Xstreams IF they are tuned to factory spec breathe just fine at 3ft. If the IP is at "standard" IP range of ~145psi vs 125psi of spec then they are prone to chattering at shallow depths but that not "because of their design" it's because someone didn't rebuild it properly.
Now, to Rob's point. Obviously on the low pressure side we don't have to worry about oxygen compatibility so the question is whether or not the 2960/3960's are suitable for pure O2 use. Unfortunately this may be where there has been marketing decisions regarding the decompression regulator versions of the Xstreams using the MK2/3 first stages where the older units were not necessarily marketed for decompression use once the Xstreams came out. While they certainly have viton kits and people have been using the 2960/3960/etc first stages with 100% decompression and from a design standpoint there is no issue about whether or not the regulators can deal with it, I suspect there is a different underlying issue to why Poseidon hasn't made mention about use with pure oxygen. Machining lubricants used during that period of time were likely not oxygen compatible and it is nearly impossible to truly remove those from the regulator bodies themselves. Similar to how most service technicians no longer keep a set of O2 only tools and just practice standard cleaning procedures on everything, most of the regulator machining is done using all O2 compatible lubricants these days which certainly helps.
Anyone doing service as a business would be off their rocker to certify a regulator for use with oxygen that isn't specifically authorized by the manufacturer, you have no problems saying "this was cleaned following industry standard guidelines for oxygen compatibility and was assembled using oxygen compatible lubricants and where possible, oxygen compatible parts but per the manufacturer is only authorized for use with up to xx% oxygen" because we live in a litigious society, especially the state where Rob lives.
So how can a diver do it? They either have to trust the history of use and their service technician and accept that it's not officially allowed, or they buy a regulator that is specifically authorized to use pure O2.
OP
So let's parse this out a bit for those reading along...
If, properly oxygen cleaned (despite not being oxygen certified), we have a regulator with a risk/reward equation that many have chosen to use for technical diving. They have judged that they are not likely to have an ignition fire since, 1) it did not ignite on initial pressurization and more importantly, 2) their technique convinces them that they are not going to introduce hydrocarbons into the gas flow pathway over the repeated tank refills and disconnections/reconnections over the service interval.
The next question is one that @Tracy and @tbone1004 have focused on - the risk of depressurization and first stage flooding. For an open ocean technical diver like me, being able to see my deco gas bottle (and any bubbles coming from it) makes leaving the valve pressurized less of a risk. That the old style Jetstream OPV in the hose connection to the second stage is more susceptible to leaking when bumped is also true, as pointed out by @Tracy . Some of my hoses will vent with a little as 0.5mm pull when pressurized. For me, that's not a deal breaker with a sidemounted bottle under my arm. But like @tbone1004 , I won't leave a "charged but off" bottle in a wreck corridor for later retrieval if it has a Jetstream on it. Nor will I leave an Atomic in the same situation.
The Jetstream, as is continuously pointed out, is sort of an upstream valve. Actually, only the servo is upstream, while the bell-shaped main valve is a bit of a hybrid. The point is, when pressurized, any valve will remain closed.
If a "charged but off" downstream valve like an R295 or C350 or Cyklon is bumped, the valve seat still wants to stay stuck to the orifice knife edge, because like a toilet bowl flapper valve, it is now pushed closed by the fact that ambient seawater pressure may be greater than the pressure inside the LP hose. Plus, there's that heavy spring keeping the valve seat flat against the orifice.
If a standard barrel style balanced second like a G250 or Apeks TX50 depressurizes, the same thing happens. The valve wants to stay closed because slightly higher seawater pressure is pushing the valve closed. Now however, the spring assisting the closure is much lighter, marginally increasing the risk that sea water can seep up the hose and reach the first stage. Actually this whole thing is probably not true unless you carry the unpressurized rig deeper in the water column. At the depth it was depressurized, hose pressure will be at ambient, with no net gradient toward the first stage unless the second is higher.
With an Atomic however, there is a small wave spring behind the orifice, which is free-floating. Under pressure, the IP pushes the larger diameter of the orifice against the seat, sealing the valve.
When depressurized, the wave spring lifts the orifice from the seat, preventing indentation while in storage. However, this opens the valve, allowing the ambient sea water access to the hose.
There's still an increasing pressure gradient as seawater rises in the hose, because the tank connection should create a cap acting as a dam against rising sea water, unless the second stage is above the first, in which case water just runs downhill.
For the Jetstream, the anatomy is a little different. There is a bell-shaped seat which is pressed against the valve outflow holes by the pressure inside the servo mechanism. But if bumped, depressurization allows the bell to collapse, allowing seawater into the hose.
(Fantastic drawing courtesy of @Fibonacci)
Again, flooding won't occur unless the second is higher than the first, or the tank connection loosens when depressurized.
In summary, I think the choice revolves more around second stage than first, if you accept that divers have been successfully oxygen cleaning and diving "uncertified" regs for a long, long time.
My 2 cents. Like Tom said,
If, properly oxygen cleaned (despite not being oxygen certified), we have a regulator with a risk/reward equation that many have chosen to use for technical diving. They have judged that they are not likely to have an ignition fire since, 1) it did not ignite on initial pressurization and more importantly, 2) their technique convinces them that they are not going to introduce hydrocarbons into the gas flow pathway over the repeated tank refills and disconnections/reconnections over the service interval.
The next question is one that @Tracy and @tbone1004 have focused on - the risk of depressurization and first stage flooding. For an open ocean technical diver like me, being able to see my deco gas bottle (and any bubbles coming from it) makes leaving the valve pressurized less of a risk. That the old style Jetstream OPV in the hose connection to the second stage is more susceptible to leaking when bumped is also true, as pointed out by @Tracy . Some of my hoses will vent with a little as 0.5mm pull when pressurized. For me, that's not a deal breaker with a sidemounted bottle under my arm. But like @tbone1004 , I won't leave a "charged but off" bottle in a wreck corridor for later retrieval if it has a Jetstream on it. Nor will I leave an Atomic in the same situation.
The Jetstream, as is continuously pointed out, is sort of an upstream valve. Actually, only the servo is upstream, while the bell-shaped main valve is a bit of a hybrid. The point is, when pressurized, any valve will remain closed.
If a "charged but off" downstream valve like an R295 or C350 or Cyklon is bumped, the valve seat still wants to stay stuck to the orifice knife edge, because like a toilet bowl flapper valve, it is now pushed closed by the fact that ambient seawater pressure may be greater than the pressure inside the LP hose. Plus, there's that heavy spring keeping the valve seat flat against the orifice.
If a standard barrel style balanced second like a G250 or Apeks TX50 depressurizes, the same thing happens. The valve wants to stay closed because slightly higher seawater pressure is pushing the valve closed. Now however, the spring assisting the closure is much lighter, marginally increasing the risk that sea water can seep up the hose and reach the first stage. Actually this whole thing is probably not true unless you carry the unpressurized rig deeper in the water column. At the depth it was depressurized, hose pressure will be at ambient, with no net gradient toward the first stage unless the second is higher.
With an Atomic however, there is a small wave spring behind the orifice, which is free-floating. Under pressure, the IP pushes the larger diameter of the orifice against the seat, sealing the valve.
When depressurized, the wave spring lifts the orifice from the seat, preventing indentation while in storage. However, this opens the valve, allowing the ambient sea water access to the hose.
There's still an increasing pressure gradient as seawater rises in the hose, because the tank connection should create a cap acting as a dam against rising sea water, unless the second stage is above the first, in which case water just runs downhill.
For the Jetstream, the anatomy is a little different. There is a bell-shaped seat which is pressed against the valve outflow holes by the pressure inside the servo mechanism. But if bumped, depressurization allows the bell to collapse, allowing seawater into the hose.
(Fantastic drawing courtesy of @Fibonacci)
Again, flooding won't occur unless the second is higher than the first, or the tank connection loosens when depressurized.
In summary, I think the choice revolves more around second stage than first, if you accept that divers have been successfully oxygen cleaning and diving "uncertified" regs for a long, long time.
My 2 cents. Like Tom said,
I also suspect that O2-cleaning instructions were simply fraught with unwanted and, more importantly, unnecessary liability for manufacturers; and there already existed plenty of hedging language and disclaimers, most everywhere, when it came to "O2-safe" products,"[F]rom the point of view of stringent U.S. aerospace guidelines and Compressed Gas Association handling standards for oxygen, nothing in general use in recreational diving is suitable for oxygen service . . . Using oxygen for diving requires you to make an informed decision to accept for yourself the risks of handing . . ."
Years ago, in Baja, we used Cyklon 300s (2980s) on deco bottles and even for oxygenating fish and various invertebrates for shipment to labs, for a number of reasons -- chiefly their low price at the time (the late eighties - early nineties equivalent of about fifty to seventy-five bucks per first stage) if you were lucky enough, when there had been a run toward balanced regulators and there were plenty of eh, "fire sales" in San Diego of old stock; that and the Cyklon's dirt-simple construction, with only about three nitrile o-rings in the first stage (which was the bigger concern of the two) to swap out; and about the same number in the second stage. The few ports, on the 2980, were sealed by semipermanent nylon washers and they never posed an issue.
We cleaned the regulators as thoroughly as we could, in the absence of an ultrasonic cleaner, with SImple Green, which had been around, in one form or another, since the 1970s, along with a Mexican all-purpose cleaner, a bit like Formula-409, called Fabuloso. The O2 tanks (maybe 52s?) that we had had arrived "pre-cleaned" from a local welder's shop and were eventually filled to only about 2200 psi, since the only "safe" booster at that time, in Cabo San Lucas, was a couple of hours away. The grease was a Christolube product, if I recall, and shipped at considerable expense, from a Canadian distributor, when the US guy refused to post to Mexico (can't blame him in retrospect; lots of stuff frequently disappeared).
There were a number of poorly-reproduced, mimeographed pamphlets and manuals, back then, which dealt with "technical" diving and O2 cleaning of regulators across brands, well before Harlow's Oxygen Hackers Companion, a few of which must have written by the author himself and circulated, long before his book. Some of that "voodoo gas" language had been almost identical -- and, in particular, his all-too memorable quote, "Don't expect me to tell you that it's OK. It's one of those things that you may get away with ten or a hundred times, but if on the thousandth time it blows up in your face you're going to feel pretty stupid in those last micro-seconds . . ."
All Hail Vance Harlow!
From the original Cyklon 300 Service Manual -- so simple -- and no combustion after, heh, heh, "ten or a hundred times," on O2:
Years ago, in Baja, we used Cyklon 300s (2980s) on deco bottles and even for oxygenating fish and various invertebrates for shipment to labs, for a number of reasons -- chiefly their low price at the time (the late eighties - early nineties equivalent of about fifty to seventy-five bucks per first stage) if you were lucky enough, when there had been a run toward balanced regulators and there were plenty of eh, "fire sales" in San Diego of old stock; that and the Cyklon's dirt-simple construction, with only about three nitrile o-rings in the first stage (which was the bigger concern of the two) to swap out; and about the same number in the second stage. The few ports, on the 2980, were sealed by semipermanent nylon washers and they never posed an issue.
We cleaned the regulators as thoroughly as we could, in the absence of an ultrasonic cleaner, with SImple Green, which had been around, in one form or another, since the 1970s, along with a Mexican all-purpose cleaner, a bit like Formula-409, called Fabuloso. The O2 tanks (maybe 52s?) that we had had arrived "pre-cleaned" from a local welder's shop and were eventually filled to only about 2200 psi, since the only "safe" booster at that time, in Cabo San Lucas, was a couple of hours away. The grease was a Christolube product, if I recall, and shipped at considerable expense, from a Canadian distributor, when the US guy refused to post to Mexico (can't blame him in retrospect; lots of stuff frequently disappeared).
There were a number of poorly-reproduced, mimeographed pamphlets and manuals, back then, which dealt with "technical" diving and O2 cleaning of regulators across brands, well before Harlow's Oxygen Hackers Companion, a few of which must have written by the author himself and circulated, long before his book. Some of that "voodoo gas" language had been almost identical -- and, in particular, his all-too memorable quote, "Don't expect me to tell you that it's OK. It's one of those things that you may get away with ten or a hundred times, but if on the thousandth time it blows up in your face you're going to feel pretty stupid in those last micro-seconds . . ."
All Hail Vance Harlow!
From the original Cyklon 300 Service Manual -- so simple -- and no combustion after, heh, heh, "ten or a hundred times," on O2:
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mictrik
Contributor
I think the second to last paragraph addresses Poseidon's position 10 years ago. I cleaned my 3790 as much as humanly possible in lieu of sending to NASA.Hi Marco!
Lets see if I can answer your questions:
- The only difference between a 3950 1st stage (it's actually a 3720 1st stage) and a 3960 1st stage (it's actually a 3790 1st stage), when it comes to parts, is the o-ring you mention. The 3960 1st stage must have the o-ring if a Jetstream 2nd stage is attached to it while the 3950 1st stage doesn't need it if there's a Cyklon 2nd stage attached to it.
- The additional o-ring used on a 3960 1st stage is there to maximize the air flow through the LP ports, as the Jetstream 2nd stage design require as much air flow as possible to seal. The Cyklon 2nd stage design do not require the same high air flow rate.
- Jetstream and Cyklon 2nd stages work at a very different intermediate pressure, so mixing these two 2nd stages on the same 1st stage, with an IP of 9,5 bar is NOT recommended. This could lead to one of the 2nd stage models failing. The Cyklon 2nd stage needs an intermediate pressure of 11,5 bar (167 psi) while the Jetstream 2nd stage needs an intermediate pressure of 8,5 bar (123 psi).
- When adding any non-Poseidon equipment to your Poseidon 1st stages, you need to make sure that the intermediate pressure these non-Poseidon components require, match the intermediate pressure that the Poseidon equipment uses. Using any breathing equipment, regardless of brand, at an intermediate pressure that is outside the manufacturer's specification, can lead to life threatening malfunctions.
- The old 2960 Jetstream 1st stage did not have a built in OPV. So to prevent the Jetstream 2nd stage from being damaged if the intermediate pressure would suddenly increase, the LP hose had a built in OPV. So the answer to your question is that if you are using a 1st stage from an 2960 Jetstream and you don't have an external OPV in one of the 1st stage LP ports, you MUST use a hose with a built in OPV.
- The reason why one of your 1st stages has two adjustment springs instead of just one, is simply because that is an old 1st stage. When that 1st stage was designed, we could not find a spring manufacturer that could make one spring strong enough, so we had to use two. In 1995, we did some upgrades to these 1st stages, among them the introduction of a single adjustment spring strong enough. If you have a 1st stage with two springs and you can get the desired intermediate pressure, you can continue using the two springs. If you can't get the desired intermediate pressure, the two springs are replaced with one spring.
I would also like to comment on your statement that you use your these regulators with both regular compressed air and 100% O2. This is NOT recommended, using these 1st stages with very high levels of O2. The reason for this is the lubricant used when these 1st stages were manufactured. For all non-Nitrox/non-O2 1st stages, we use a silicone based lubricant and this is pretty much impossible to wash away, to get a 1st stage O2 clean. Doing this can lead to a 1st stage oxygen burn, something we have seen evidence of in the past.
As far as we know, there's only one organization that can clean a 1st stage where a silicone based lubricant has been used, to make it O2 clean, and that is NASA.
Diver's safety is our prime concern thus it is very important that you let a trained service technician work on your equipment to ensure that they are set up/adjusted the way they are supposed to, to ensure functionality. I fully understand and respect that you have difficulties finding a Poseidon Service technician in your area, but I recommend that you check out our dealer location on our website (Poseidon) or get in touch with our representative in Canada (jack@poseidoncanada.ca) to track down a service center in your area that can assist you with your Poseidon equipment.
Med Vänliga Hälsningar
Jörgen Nilsson
TravelGas
Contributor
After reading this, am I correct that the use of Poseidon Odin 3960 on a Deco or O2 bottle with Vito’s O rings is not recommended for Deep Tech Ocean diving ?
Would the purchase of the $299 Dive Rite Deco / O2 Regulator be the best way to go for the O2 40 cu ft bottle?
Would the purchase of the $299 Dive Rite Deco / O2 Regulator be the best way to go for the O2 40 cu ft bottle?
Good read you guys...Thanks...I used Poseidon's for years and years in the cold with the condom cap. We never had an issue. I do understand you guys are talking about leaving on a deco bottle not for primary reg. Here is a pic from the late 80's to early 1990's when Zeagle was a concept and DUI owner would fly out and custom measure you for their suits
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I have a friend that had an jetstream blow up and shoot flames on his o2 bottle. He was fond of the wooosh-pop that they make when turning them on and turned his deco bottle on a little too fast. Started shooting flames out of the side of the reg and he had to turn the bottle off before the flames migrated in.
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