God Bless you ALEC, your videos are the best. My wife and I are currently taking the SDI Nitrox certification course and were so confused by the eLearning explanation of chapter 4 (Equipment for Nitrox diving) specifically talking about OCA and SCUBA air and how your equipment's must be cleaned to maintain it's 02 rating. Your explanation of the differences of OCA and Scuba air were spot on. We had an AHA moment (the light bulb appeared over our heads). Your explanation was so amazing and clear to us. My wife said to subscribed to his channel now and I did. Thank you so much for that video because the course material left us scratching our heads in confusion.
Glad to have helped out and hope you both passed the course with perfect marks. Many divers mix up plain scuba air, OCA and EAN mixes. Helping divers widen their understand of our sport is my goal and to have a laugh doing it. A
Alex, thank you for interesting video. Some clarifications, I think, may be worth to add. Nowadays nitril rubber O-rings are taken as oxygen compatible and widely used in decompression stage tanks and regulators instead of Viton ones. Also most modern regulators are nitrox compatible up to 40% mix when delivered from factory and stay such if serviced according to manufacturer's instructions. The tank and valve requiresoxygen cleaning for nitrox service only if a) mixes richer than 40% are used or b) tank is filled using partial pressure method. Nowadays more and more either CFM (continuous flow mixing) or membran method are used so for recreational nitrox diver the cleaning is not necessarily an issue. Then a tiny word of warning. During my 25+ years of diving I have met a few explosed compressors used for CFM (operator errors) and explosed tank valve (rebreather ox tank during fill). Whenever high partial pressure oxygen is handled one have to be careful with cleaniness and procedures. When O2 is in intermediate pressure it stands already much more than in tank pressure. Therefore pay extra attention to the cleaniness of the O-ring between your tank and reg when you use nitrox mixes.
Totally agree on the real dangers of PP mixing as I used to do it a looong time ago before the stick method was available. I plan to do a future video on nitrox compatible gear when buying new and rated to 40%. This was to answer several emails about OCA from viewers to answer a few question at a time. Next video is on lubricants to answer basic questions on what are the types of lubs and which is O2 compatible. I used to try and answer a lot more questions per video but they got to be long so breaking it down into smaller easier to absorb videos. Hope you understand. A
Thanks Alec, this was really informative. I know a lot of diving accidents occur when people feel overconfident, but lack the correct training, and I think that as an OW diver with 100+ dives under my belt, trying out enriched are "for the heck of it" is exactly the kind of stupid mistake I might have made, without realising it could damage my equipment. So, thanks to for reminding my I'm not as expert as I sometimes think I am!
Here in UK the main difference in the OCA standard is that the amount of oil droplets/mist must be less than 0.1mg/m3, a fifth of that for regular scuba air. I'm sure it's similar in North America. It's this oil that's the primary risk for spontaneous combustion so it's not something you want accumulating in your gear. That's why OCA/Nitrox/Trimix compressors, the source of the oil, are expensive to engineer, buy and maintain, and therefore why you pay extra for the privilege! Neoprene, silicone and Viton O-rings are O2 compatible but silicone grease generally isn't because it contains other reactive hydrocarbons. Just to illustrate the issue, I know a guy who was flying an F-4 fighter, he and his back-seater both breathing 100% O2, as is normal at altitude. The navigator dropped his mask, took a bite of a greasy cheese sandwich and ended up with severe facial burns and a melted mask. At high O2 concentration you don't need high temperature or pressure for spontaneous combustion!
Ouch, that's something pilots should not be doing! Agree with your points Tim about OCA standards. Don't have my service binders but our store's compressors were checked several times a year for air quality and I think it was particulates that cause the spark of ignition. Thanks for sharing these cool stories. A
As a tech divers I do all of my deep dives in decompression mode. A 100 ft dive for extended duration I concider decompression on standard 21%. But if I'm breathing 21% at 180 ft let's say, now that is a big deal. So concider using 36% nitrox, or less percentage as an accent gas making the switch (at the required depth) to off gas those pesky nitrogen molecules. Like Alex said nitrox can have multiple applications. I've been doing decompression diving for 35 year's my style has never done me wrong (never say never DCI can hit at any time or place) And when nitrox became a thing, that was fantastic an added level of protection against DCI Best of luck to you all and happy diving
Thanks for sharing your experiences Mark. I remember when "VooDoo" gas first arrived and warned never to use it. Even though as a commercial diver I used it for many years with increased safety like you say. Diving has come a long way in safety from my early stone age diving days. A
You should not have to get it O2 cleaned as the intermediate pressure in a 2nd stage is around 140-150psi, much lower than the 3,000 psi from a full tank. Read the reg's manual, paper or online, and should see that it is O2 compatible to 40% from brand new. A
Now explain to us if the LDS can create their own “O2 comparable air” from their compressor such as a Bauer with a triplex filter cartridge? Or are you suggesting the LDS be purchasing medical grade clean air from their gas supplier?
Oxygen Compatible Air is easy to make if the LDS is already making nitrox using the stick method, not partial pressure blending. As long as they test their OCA air regularly, should not be a problem going between nitrox and OCA. A
Hej Alec. I'm remembering the video of pillar mixing air in to the compressor. with the O2 sensor that you showed. does the compressor need to have changed every single o-ring that touches the oxygen? //Jony in Sweden.
If you mean a store compressor, it depends on the nitrox blending method. Many stores compressor feed into a nitrox 'stick' to create a 32% O2 mix. Some do partial pressure blending that mud have all O2 compatible rings. If you have specific questions about compressors & blending, ask the scuba community on www.scubaboard.com for assistance. A
Hi Alec .That was quite an interesting topic. One question that it raises is about reg hoses and diaphragms and flat disk seals many are rubber do they all need changing too or just cleaned well as the rest of the components. take care Owen m
I have exactly the same question about all resilient materials other than Orings that are used in a regulator, I understand that oxygen compatible lube is mandatory, ( anyway, I use cristo-lube oxygen compatible lube when servicing my regulators ) but all the intermediate and high pressure hoses that are exposed to EAN are not specifically designed for use with other media than standard air ( 21% O2 ) so I can question the technical validity of such a conversion when main components as hoses and diaphragms are not originally designed for that use and O2 safe versions of these components are not available.
Hi Owen. First off hose o-rings today are all sold as nitrox compatible otherwise you would have to replace each hose's o-ring which may damage them during replacement. Any plastic part is fine only neoprene o-rings are subject to O2 deterioration. There are lots of parts in a 1st and 2nd stage but only proper o-rings and lub are needed to be nitrox compatible. Hope this helps and dive safe. A
An interesting (and important) point that I hadn't heard before about requesting O2 clean fills for an EAN clean tank. I don't recall this being discussed in my course (20 years ago...maybe it is now). With O2 clean regs, is it the same, i.e., should they be cleaned if used with an O2 tank before being used again with EAN?
I think your question is can clean regs & 1st stage be used with nitrox (up to 40%) and regular air tank fills without re-cleaning? Yes, if the fill uses OCA compatible air. If your talking a 100% oxygen fill, like partial pressure filling or a O2 tank only, if your setup was properly O2 cleaned, switching between 100% O2 and EAN would not be a problem. A
I’m heading to Bonaire next month as I do every year with my local dive shop and decided to start using Nitrox. I just had my regulator serviced by my dive shop but I never mentioned I would be using Nitrox nor did he ask. My regulator is only about 6 years old. Do I need to be concerned with what type of O rings that are in my personal regulator??? Gosh, I don’t want to have any problems.
The vast majority of recreational dive shops make Nitrox using a 'stick' to fill tanks so no worries as only 32% O2 is used in the fill. No need to get your gear O2 cleaned until 40% O2 or filling using the partial pressure fill method that adds 100% O2 to create the final mix. Have a great time in Bonaire and dive the salt pier if you can. A
As for BCD O2 cleaning after using silicone spray, if under 40% not needed, if greater it needs to be checked for compatibility with o-rings and lub. Don't risk a problem over a few bucks my friend. A
I've been doing some research for dive computers, and I'm noticing a few brands have "02 clean transmitters". Is this a sales tactic, or something I actually have to consider?
The key word is O2 "compatible", clean is not a definitive answer to me. If it does not say compatible, you should not mix regular air and enriched air. A
is there a way to find out if you got OCA instead of "regular" air? i've seen some sketchy dive shops in remote locations rent out tanks with broken o-rings and ancient hydro dates, i wouldn't put it past them to use a regular air but claim it's OCA just to get your money.
Ask to see their certificate of air quality. Check the date and all measurements pass. Anyone not willing to show it is suspect as its like asking for a mechanics license before working on your car. Any shop selling OCA but not delivering it is in violation of the law and putting divers are risk. A
@@AlecPeirceScuba_SeaHunter my regulator is EAN40-compatible from the manufacturer, if i dive on regular air, do i need to get this regulator cleaned before using EAN32 or EAN40?
Awesome video, Alec. Thanks for the info. I have an unrelated question. I notice that when I am diving my mask puts pressure on the bottom of my nose, like the mask wants to pop off my head and catches itself in my nose on the way off. It does this despite how lose or tight the mask straps are. Is this an example of mask squeeze, or a problem unique to the pumpkin I call a head? (The mask is a Cressi Big Eye in case it matters, but I've experienced it with other mask brands and models as well).
From your comment, it may be your breathing a bit out of your nose which makes it buoyant and any ascent would make the mask 'lift up' due to the increased air pressure inside. Suggestions are to tighten the strap a bit, just a bit more, keep the band low over your ears so it pulls straight back, not upwards. Hope this helps. A
@@AlecPeirceScuba_SeaHunter thanks Alec, I will try all of those suggestions. I think you may be correct about me breathing out of my nose a little as well.
I feel like a side by side comparrison of the test results and standards would have been helpful. OCA is no real mystery and does not need to be complicated or scary. I test the air from my compressor annually ( I replace the filter well before it is due and only use very small volume) I have also fixed up and sold a couple of other small compressors and have had them all tested to OCA standards. They have all passed the OCA test without any special modifications. I think that any properly maintained compressor with clean inlet air should not have a problem passing for OCA, any extra filters are just insurance. A Reputable dive shop should test multiple times a year and change filters before the end of their useful life. It is probably more important to just keep tabs on weather or not your shop is following compressor best practices. If you tend to switch back and forth you probably should have dedicated nitrox tanks just to avoid conflict when you have them filled.
Unfortunately this video rises more questions than answers: What happened if regular regulator will be used with O2 (I guess some grease can ignite, but what else)? Why silicon grease isn't good, but silicon O-ring is suitable? Would steel tank corrode quickly if filled with O2 or nitrox? What makes air not O2 compatible? And so on...
Well first things first, unless you are a tech diver you are never going to be using a reg with pure oxygen, just up to 40% oxygen content. Most regs and service kits are available, and typically come from the factory, to use with nitrox up to 40%. The grease, the orings, and even the diaphragm can combust. Tech divers do have pure oxygen regs, but most of those are cheap regs because oxygen is used only super shallow (20ft or less) thus you can get away with a cheap reg. Quite a few people though use normal regs that are oxygen cleaned. Steel tanks won't corrode faster as water content is what determines rusting. And the primary difference between oxygen clean air, and normal air is the oil and dust content as those are possible fuel for fires.
@@toriless The 40% max is the recreational max, and was picked as you are more likely to hit NDL before hitting the CNS limits. I personally have a 50% and pure oxygen bottle for technical diving.
God Bless you ALEC, your videos are the best. My wife and I are currently taking the SDI Nitrox certification course and were so confused by the eLearning explanation of chapter 4 (Equipment for Nitrox diving) specifically talking about OCA and SCUBA air and how your equipment's must be cleaned to maintain it's 02 rating. Your explanation of the differences of OCA and Scuba air were spot on. We had an AHA moment (the light bulb appeared over our heads). Your explanation was so amazing and clear to us. My wife said to subscribed to his channel now and I did. Thank you so much for that video because the course material left us scratching our heads in confusion.
Glad to have helped out and hope you both passed the course with perfect marks. Many divers mix up plain scuba air, OCA and EAN mixes. Helping divers widen their understand of our sport is my goal and to have a laugh doing it.
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Alex, thank you for interesting video. Some clarifications, I think, may be worth to add. Nowadays nitril rubber O-rings are taken as oxygen compatible and widely used in decompression stage tanks and regulators instead of Viton ones. Also most modern regulators are nitrox compatible up to 40% mix when delivered from factory and stay such if serviced according to manufacturer's instructions.
The tank and valve requiresoxygen cleaning for nitrox service only if a) mixes richer than 40% are used or b) tank is filled using partial pressure method. Nowadays more and more either CFM (continuous flow mixing) or membran method are used so for recreational nitrox diver the cleaning is not necessarily an issue.
Then a tiny word of warning. During my 25+ years of diving I have met a few explosed compressors used for CFM (operator errors) and explosed tank valve (rebreather ox tank during fill). Whenever high partial pressure oxygen is handled one have to be careful with cleaniness and procedures. When O2 is in intermediate pressure it stands already much more than in tank pressure. Therefore pay extra attention to the cleaniness of the O-ring between your tank and reg when you use nitrox mixes.
Totally agree on the real dangers of PP mixing as I used to do it a looong time ago before the stick method was available. I plan to do a future video on nitrox compatible gear when buying new and rated to 40%. This was to answer several emails about OCA from viewers to answer a few question at a time. Next video is on lubricants to answer basic questions on what are the types of lubs and which is O2 compatible. I used to try and answer a lot more questions per video but they got to be long so breaking it down into smaller easier to absorb videos. Hope you understand.
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Thanks Alec! Good info as usual!
Keep em coming!
Thanks! Will do!
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Thanks Alec, this was really informative. I know a lot of diving accidents occur when people feel overconfident, but lack the correct training, and I think that as an OW diver with 100+ dives under my belt, trying out enriched are "for the heck of it" is exactly the kind of stupid mistake I might have made, without realising it could damage my equipment. So, thanks to for reminding my I'm not as expert as I sometimes think I am!
You're welcome and glad to give you confidence in to do the right thing when considering EAN fills.
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Here in UK the main difference in the OCA standard is that the amount of oil droplets/mist must be less than 0.1mg/m3, a fifth of that for regular scuba air. I'm sure it's similar in North America. It's this oil that's the primary risk for spontaneous combustion so it's not something you want accumulating in your gear. That's why OCA/Nitrox/Trimix compressors, the source of the oil, are expensive to engineer, buy and maintain, and therefore why you pay extra for the privilege! Neoprene, silicone and Viton O-rings are O2 compatible but silicone grease generally isn't because it contains other reactive hydrocarbons. Just to illustrate the issue, I know a guy who was flying an F-4 fighter, he and his back-seater both breathing 100% O2, as is normal at altitude. The navigator dropped his mask, took a bite of a greasy cheese sandwich and ended up with severe facial burns and a melted mask. At high O2 concentration you don't need high temperature or pressure for spontaneous combustion!
Ouch, that's something pilots should not be doing! Agree with your points Tim about OCA standards. Don't have my service binders but our store's compressors were checked several times a year for air quality and I think it was particulates that cause the spark of ignition. Thanks for sharing these cool stories.
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Missed your videos!
Me too!! More coming weekly until winter. Then Kevin gets lazy and we release one every two weeks.
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As a tech divers I do all of my deep dives in decompression mode. A 100 ft dive for extended duration I concider decompression on standard 21%. But if I'm breathing 21% at 180 ft let's say, now that is a big deal. So concider using 36% nitrox, or less percentage as an accent gas making the switch (at the required depth) to off gas those pesky nitrogen molecules.
Like Alex said nitrox can have multiple applications.
I've been doing decompression diving for 35 year's my style has never done me wrong (never say never DCI can hit at any time or place) And when nitrox became a thing, that was fantastic an added level of protection against DCI
Best of luck to you all and happy diving
Thanks for sharing your experiences Mark. I remember when "VooDoo" gas first arrived and warned never to use it. Even though as a commercial diver I used it for many years with increased safety like you say. Diving has come a long way in safety from my early stone age diving days.
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thank you Alec! now i understand why the price for technical diving is soo high!
A lot of backup gear and redundancy in tec, and $$$.
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Do I need to have my regulator cleaned if I just bought it and only Made 8 dives on a brand new regulator if I intend on going nitrox next thank you
You should not have to get it O2 cleaned as the intermediate pressure in a 2nd stage is around 140-150psi, much lower than the 3,000 psi from a full tank. Read the reg's manual, paper or online, and should see that it is O2 compatible to 40% from brand new.
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Now explain to us if the LDS can create their own “O2 comparable air” from their compressor such as a Bauer with a triplex filter cartridge? Or are you suggesting the LDS be purchasing medical grade clean air from their gas supplier?
Oxygen Compatible Air is easy to make if the LDS is already making nitrox using the stick method, not partial pressure blending. As long as they test their OCA air regularly, should not be a problem going between nitrox and OCA.
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My local shop tells us to ask for EAN21 or Nitrox 21, for OCA
Similar terms for OCA quality air but you get the point.
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Hej Alec. I'm remembering the video of pillar mixing air in to the compressor. with the O2 sensor that you showed. does the compressor need to have changed every single o-ring that touches the oxygen?
//Jony in Sweden.
If you mean a store compressor, it depends on the nitrox blending method. Many stores compressor feed into a nitrox 'stick' to create a 32% O2 mix. Some do partial pressure blending that mud have all O2 compatible rings. If you have specific questions about compressors & blending, ask the scuba community on www.scubaboard.com for assistance.
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Thanx! Does the same rules apply with our first stage and regulator?
yes
Yes it does! Everything your air fill touches have to be OCA compatible, 1st stage , 2nd stage , tank, safe 2nd reg.
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Hi Alec .That was quite an interesting topic. One question that it raises is about reg hoses and diaphragms and flat disk seals many are rubber do they all need changing too or just cleaned well as the rest of the components.
take care Owen m
I have exactly the same question about all resilient materials other than Orings that are used in a regulator, I understand that oxygen compatible lube is mandatory, ( anyway, I use cristo-lube oxygen compatible lube when servicing my regulators ) but all the intermediate and high pressure hoses that are exposed to EAN are not specifically designed for use with other media than standard air ( 21% O2 ) so I can question the technical validity of such a conversion when main components as hoses and diaphragms are not originally designed for that use and O2 safe versions of these components are not available.
@@jacquespoirier9071 Most regs are Nitrox compatible these days.
Hi Owen. First off hose o-rings today are all sold as nitrox compatible otherwise you would have to replace each hose's o-ring which may damage them during replacement. Any plastic part is fine only neoprene o-rings are subject to O2 deterioration. There are lots of parts in a 1st and 2nd stage but only proper o-rings and lub are needed to be nitrox compatible. Hope this helps and dive safe.
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An interesting (and important) point that I hadn't heard before about requesting O2 clean fills for an EAN clean tank. I don't recall this being discussed in my course (20 years ago...maybe it is now). With O2 clean regs, is it the same, i.e., should they be cleaned if used with an O2 tank before being used again with EAN?
I think your question is can clean regs & 1st stage be used with nitrox (up to 40%) and regular air tank fills without re-cleaning? Yes, if the fill uses OCA compatible air. If your talking a 100% oxygen fill, like partial pressure filling or a O2 tank only, if your setup was properly O2 cleaned, switching between 100% O2 and EAN would not be a problem.
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I’m heading to Bonaire next month as I do every year with my local dive shop and decided to start using Nitrox. I just had my regulator serviced by my dive shop but I never mentioned I would be using Nitrox nor did he ask. My regulator is only about 6 years old. Do I need to be concerned with what type of O rings that are in my personal regulator??? Gosh, I don’t want to have any problems.
Generally it’s all fine until you got to over 40% oxygen.
Absolutely not, they’re good up to 40%….after that you’d want an O2 clean reg.
The vast majority of recreational dive shops make Nitrox using a 'stick' to fill tanks so no worries as only 32% O2 is used in the fill. No need to get your gear O2 cleaned until 40% O2 or filling using the partial pressure fill method that adds 100% O2 to create the final mix.
Have a great time in Bonaire and dive the salt pier if you can.
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@@AlecPeirceScuba_SeaHunter thanks Alec. We do the salt pier every year as long as the current isn’t too strong. Salt pier is one of my favorites.
Hi Alec, I lubricate my BC inflator with that silicon spray you show in the video. Does it mean that I can’t dive
As for BCD O2 cleaning after using silicone spray, if under 40% not needed, if greater it needs to be checked for compatibility with o-rings and lub. Don't risk a problem over a few bucks my friend.
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I've been doing some research for dive computers, and I'm noticing a few brands have "02 clean transmitters". Is this a sales tactic, or something I actually have to consider?
The key word is O2 "compatible", clean is not a definitive answer to me. If it does not say compatible, you should not mix regular air and enriched air.
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is there a way to find out if you got OCA instead of "regular" air? i've seen some sketchy dive shops in remote locations rent out tanks with broken o-rings and ancient hydro dates, i wouldn't put it past them to use a regular air but claim it's OCA just to get your money.
Ask to see their certificate of air quality. Check the date and all measurements pass. Anyone not willing to show it is suspect as its like asking for a mechanics license before working on your car. Any shop selling OCA but not delivering it is in violation of the law and putting divers are risk.
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@@AlecPeirceScuba_SeaHunter my regulator is EAN40-compatible from the manufacturer, if i dive on regular air, do i need to get this regulator cleaned before using EAN32 or EAN40?
Viton costs the same but you still need to use the right kind. Viton is also backward compatible with air only.
You are right my friend.
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Is it just removing hydrogen that makes it compatible or what else do the need to treat the air so it is oxygen compatible air.
It is air quality that determines OCA standards. Removing particles (ie. oil), is key to prevent oxygen interacting and causing an explosion.
Awesome video, Alec. Thanks for the info. I have an unrelated question. I notice that when I am diving my mask puts pressure on the bottom of my nose, like the mask wants to pop off my head and catches itself in my nose on the way off. It does this despite how lose or tight the mask straps are. Is this an example of mask squeeze, or a problem unique to the pumpkin I call a head? (The mask is a Cressi Big Eye in case it matters, but I've experienced it with other mask brands and models as well).
From your comment, it may be your breathing a bit out of your nose which makes it buoyant and any ascent would make the mask 'lift up' due to the increased air pressure inside. Suggestions are to tighten the strap a bit, just a bit more, keep the band low over your ears so it pulls straight back, not upwards. Hope this helps.
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@@AlecPeirceScuba_SeaHunter thanks Alec, I will try all of those suggestions. I think you may be correct about me breathing out of my nose a little as well.
I feel like a side by side comparrison of the test results and standards would have been helpful. OCA is no real mystery and does not need to be complicated or scary. I test the air from my compressor annually ( I replace the filter well before it is due and only use very small volume) I have also fixed up and sold a couple of other small compressors and have had them all tested to OCA standards. They have all passed the OCA test without any special modifications. I think that any properly maintained compressor with clean inlet air should not have a problem passing for OCA, any extra filters are just insurance. A Reputable dive shop should test multiple times a year and change filters before the end of their useful life. It is probably more important to just keep tabs on weather or not your shop is following compressor best practices. If you tend to switch back and forth you probably should have dedicated nitrox tanks just to avoid conflict when you have them filled.
Good points Kevin, thanks for sharing with everyone.
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Unfortunately this video rises more questions than answers: What happened if regular regulator will be used with O2 (I guess some grease can ignite, but what else)? Why silicon grease isn't good, but silicon O-ring is suitable? Would steel tank corrode quickly if filled with O2 or nitrox? What makes air not O2 compatible? And so on...
Well first things first, unless you are a tech diver you are never going to be using a reg with pure oxygen, just up to 40% oxygen content. Most regs and service kits are available, and typically come from the factory, to use with nitrox up to 40%. The grease, the orings, and even the diaphragm can combust.
Tech divers do have pure oxygen regs, but most of those are cheap regs because oxygen is used only super shallow (20ft or less) thus you can get away with a cheap reg. Quite a few people though use normal regs that are oxygen cleaned.
Steel tanks won't corrode faster as water content is what determines rusting. And the primary difference between oxygen clean air, and normal air is the oil and dust content as those are possible fuel for fires.
@@Teampegleg Thank you!
@@Teampegleg I have seen 42% but 38% is the most common.
@@toriless The 40% max is the recreational max, and was picked as you are more likely to hit NDL before hitting the CNS limits.
I personally have a 50% and pure oxygen bottle for technical diving.
My next video explains the two major types of lubricants to answer your questions Yury. The community answers below cover your other questions.
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Then you can add helium for a Trimix.
I'm not a tec expert on tri-fills. A very long time ago I was but todays gear and training is much safer than back in the stone age of diving.
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