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carbon monoxide in tanks - cozumel
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I've dove with Dressel 6 times (the last time Dec 2009) and I know for a fact they have there own compressor. My only note of caution is last time they were really busy and most my fills were hot. I would loose about 500 PSI within the first 15 feet of my descent as the tank cooled. I've never had this problem before but the dive shop was very very very busy and they were always short tanks and the boats were at full capacity. During the week we had to come into dock almost every time to get the tanks for the 2nd dive. I like the dive shop a lot and when I take my kids 11 and 10 years old they always take extra care and we get are own dive instructor which makes for a nice family dive. (note: It is my understanding that all dive shop dive masters are actually instructors at Dressel)
R
redacted
Guest
I believe that much pressure lose would put those tanks up in the 180 degrees F range which seems unrealistically high. A lose of 200 to 300 psi due to temp change would be more reasonable. Perhaps the other 100 to 200 psi were consumed waiting on the surface and in the initial descent.
Awap, your post got me thinking... and I think you are exactly correct about the 200-300 drop in psi from temp change. The tanks were also a little light around 2750-2800 starting PSI so then you loose another 200-300 psi and your down 500 psi. I personally don't care if my tank is a little light because my air consumption is typically one of the least... but I've dove with plenty of divers who want to see there tank start around 3200 starting psi so they can have a nice dive.
Heath Sapp
Contributor
I dove this weekend had a tank that was filled to 3600psi. Then my next tank was 2650 psi. Then got a tank at 3200 psi. all tanks were cool I had hoped that my burst disk would not go, Other guys told me not to worry about it but I was was removed the regulator vented it done to 3000 psi. Was this ok or was I be stupid?
Because the tank was going into the water shortly, I would have kept the extra air. The only time I've ever seen a disc blow was during filling. Basically, the disc is there to prevent overfilling and to blow in case of over heating. Once the tank is over pressurized, I do not think you are solving any issues by removing any air, unless you expected the tank to sit in a hot environment before use.
But you erred on the safe side, so no, definitely not stupid.
Couv
But you erred on the safe side, so no, definitely not stupid.
Couv
beachnik
Contributor
I've just heard back from a friend in the industry on the island.
In the wake of the Feb 12 incident involving Dive Palancar, my friend decided it would be a good time for a routine visit to Meridiano (if you haven't read all the posts above, Meridiano - the main filler on the island - did not fill the tanks in this incident).
The comments I've received in return about Meridiano have been positive - similar to the quote from Memo Mendoza in one of the above posts. My friend also commented that Meridiano has, in the past, been cooperative and receptive to suggestions to improve safety. (I've called Analox - they said they would contact Meridiano and pitch them on the CO Clear)
This post is simply a general comment - nothing more. I thought it was something worth sharing - and no one asked me to post this here.
I've been diving a long time, but really hadn't paid any attention to the issue of CO. This incident and all these posts have been a wake up call. I'm inclined to think that no matter where you're diving and no matter who is filling your tanks, it's probably a good idea to have a personal CO tester.
In the wake of the Feb 12 incident involving Dive Palancar, my friend decided it would be a good time for a routine visit to Meridiano (if you haven't read all the posts above, Meridiano - the main filler on the island - did not fill the tanks in this incident).
The comments I've received in return about Meridiano have been positive - similar to the quote from Memo Mendoza in one of the above posts. My friend also commented that Meridiano has, in the past, been cooperative and receptive to suggestions to improve safety. (I've called Analox - they said they would contact Meridiano and pitch them on the CO Clear)
This post is simply a general comment - nothing more. I thought it was something worth sharing - and no one asked me to post this here.
I've been diving a long time, but really hadn't paid any attention to the issue of CO. This incident and all these posts have been a wake up call. I'm inclined to think that no matter where you're diving and no matter who is filling your tanks, it's probably a good idea to have a personal CO tester.
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Meridiano has a very good reputation and much of the island Ops depend on them. I guess that they have several compressors and will need that many monitors but then I am a firm believer that every commercial compressor should have one operating and calibrated quarterly, and the per tank cost is neglible.
Yeah, I'm looking forward to what Analox presents this summer and will probly get one if it looks as good as their other instruments. Failing that, I'll probly break down and get the set-up suggested by Swamp Diver - but since I have a Pocket CO analyzer that works, I'll wait.
If I had a trip planned in the next few months, I'd get one now - either the cheaper Pocket CO to be replaced later or just go with SD's current suggestions. Even when I replace the Pocket CO, I'll still keep it calibrated and use it for other instances. Now that I have the two page instructions that came with their little calibration gas can, I may just buy a 17 liter of 100 ppm to keep it updated whenever I order 10 ppm gas - combine the shipping.
I suppose it would be wrong to duplicate their instructions, but $50 including shipping for a small can to calibrate 3 times is a bit much.
swamp diver
Contributor
After seeing this link earlier in the thread I decided to contact PADI head office and see what was behind the recent change in their air testing guidelines?
http://www.epa.gov/region10/pdf/dive_team/dt_divers_how_clean_is_your_air_dec09.pdf
Previously all PADI shops in Canada and the US were required to test quarterly to the Compressed Gas Standard (CGA) Grade E standard. While this was PADI policy it was rarely enforced, however the fact there was an agency guideline meant that in the event of an incident involving questionable air quality the judge could look to this policy for guidance. A shop that had not tested quarterly could be found as failing to meet the recommended PADI guideline and be held liable in the event of an injury or fatality related to contaminated air.
The PADI representative said that the reason they changed the frequency of testing from quarterly to an interval the "shop owner" felt was appropriate was that the interval should depend on the volume of air pumped. A shop which shut down for part of the year would not necessarily need to test quarterly whereas a shop which fills a few hundred tanks a day should be testing more frequently than quarterly. He stated that in the later case with a high volume shop the PADI quarterly requirement was often taken as fixed in stone and now that the quarterly requirement has been removed these high volume fill station owners will apparently begin to test even more frequently. Somehow I don't think so.
Instead PADI will now defer to the local authority having jurisdiction with regard to the frequency of sampling and to what compressed air standard must be met. Most jurisdictions in Canada and the USA do not have a standard which covers recreational dive air specifically so the sport diver has been left with little to no protection whatsoever. Florida still requires its recreational dive shops to test quarterly which I believe is the only state to do so. The better shops in both countries who are truly interested in diver safety will continue to test quarterly, however many will drop their testing frequency or not test at all which has now happened at two PADI shops in our area which used to test quarterly.
The real problems will be in those jurisdictions such as Mexico and other tropical areas where there is no local authority whatsoever with regard compressed air quality. PADI still states their facilities in these regions must test to the CGA Grade E standard if no local standard exists but conveniently the CGA standard does not define a testing frequency. If the shop owner feels an annual test is enough that will suffice. In the past one could be fairly confident to find most 5 star PADI resorts in the tropics were testing quarterly, but this may no longer be the case. Diver beware.
Personally I think there is more to this policy change than meets the eye. The stated reasons of simply allowing the fill station owner to determine the frequency of testing which reflects the volume of air pumped may sound reasonable, but in the mom and pop dive industry we all know that testing frequency will decrease or end altogether. It does appear though that by no longer stating a minimum quarterly testing frequency for its affiliated shops and resorts PADI has reduced its liability in the event of an injury or death traced to contaminated air. In the past the shop owner, PADI, and the local regulator may have had to testify, but by deferring to the local authority which in many jurisdictions does not exist PADI has effectively removed itself from the potential liability net cast by the lawyers.
Probably a smart business move on the part of PADI as they have transferred the onus of responsibility entirely to the shop, but a very regressive step for diver safety around the globe, particularly since PADI has somewhere about 80 percent of the sport diving market. Rather than showing leadership by setting the air quality assurance bar at an appropriate level PADI has abdicated their responsibility.
Divers will now have to vote with their credit card and should only frequent those PADI shops which do continue to partake in quarterly testing. Unless we divers continue to make air purity an important safety issue with the shops we patronize testing will go by the wayside in many diver tourist areas.
I do see that NAUI still requires quarterly testing for its facilities, but there is no enforcement of the policy. At least with the minimum quarterly testing policy a diver can cite this at a NAUI shop which does not meet the stated quarterly testing frequency.
NAUI Worldwide Dive Center Code Of Ethics
http://www.epa.gov/region10/pdf/dive_team/dt_divers_how_clean_is_your_air_dec09.pdf
Previously all PADI shops in Canada and the US were required to test quarterly to the Compressed Gas Standard (CGA) Grade E standard. While this was PADI policy it was rarely enforced, however the fact there was an agency guideline meant that in the event of an incident involving questionable air quality the judge could look to this policy for guidance. A shop that had not tested quarterly could be found as failing to meet the recommended PADI guideline and be held liable in the event of an injury or fatality related to contaminated air.
The PADI representative said that the reason they changed the frequency of testing from quarterly to an interval the "shop owner" felt was appropriate was that the interval should depend on the volume of air pumped. A shop which shut down for part of the year would not necessarily need to test quarterly whereas a shop which fills a few hundred tanks a day should be testing more frequently than quarterly. He stated that in the later case with a high volume shop the PADI quarterly requirement was often taken as fixed in stone and now that the quarterly requirement has been removed these high volume fill station owners will apparently begin to test even more frequently. Somehow I don't think so.
Instead PADI will now defer to the local authority having jurisdiction with regard to the frequency of sampling and to what compressed air standard must be met. Most jurisdictions in Canada and the USA do not have a standard which covers recreational dive air specifically so the sport diver has been left with little to no protection whatsoever. Florida still requires its recreational dive shops to test quarterly which I believe is the only state to do so. The better shops in both countries who are truly interested in diver safety will continue to test quarterly, however many will drop their testing frequency or not test at all which has now happened at two PADI shops in our area which used to test quarterly.
The real problems will be in those jurisdictions such as Mexico and other tropical areas where there is no local authority whatsoever with regard compressed air quality. PADI still states their facilities in these regions must test to the CGA Grade E standard if no local standard exists but conveniently the CGA standard does not define a testing frequency. If the shop owner feels an annual test is enough that will suffice. In the past one could be fairly confident to find most 5 star PADI resorts in the tropics were testing quarterly, but this may no longer be the case. Diver beware.
Personally I think there is more to this policy change than meets the eye. The stated reasons of simply allowing the fill station owner to determine the frequency of testing which reflects the volume of air pumped may sound reasonable, but in the mom and pop dive industry we all know that testing frequency will decrease or end altogether. It does appear though that by no longer stating a minimum quarterly testing frequency for its affiliated shops and resorts PADI has reduced its liability in the event of an injury or death traced to contaminated air. In the past the shop owner, PADI, and the local regulator may have had to testify, but by deferring to the local authority which in many jurisdictions does not exist PADI has effectively removed itself from the potential liability net cast by the lawyers.
Probably a smart business move on the part of PADI as they have transferred the onus of responsibility entirely to the shop, but a very regressive step for diver safety around the globe, particularly since PADI has somewhere about 80 percent of the sport diving market. Rather than showing leadership by setting the air quality assurance bar at an appropriate level PADI has abdicated their responsibility.
Divers will now have to vote with their credit card and should only frequent those PADI shops which do continue to partake in quarterly testing. Unless we divers continue to make air purity an important safety issue with the shops we patronize testing will go by the wayside in many diver tourist areas.
I do see that NAUI still requires quarterly testing for its facilities, but there is no enforcement of the policy. At least with the minimum quarterly testing policy a diver can cite this at a NAUI shop which does not meet the stated quarterly testing frequency.
NAUI Worldwide Dive Center Code Of Ethics
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It would be great if divers were educated about the potential for bad air but the fact of the matter is that the PADI course, at least when I took it, glossed over it like the risk was negligible and gave the advice that the best way to avoid contaminated air was to frequent a PADI affiliated shop. We now know that "advice" is nothing but marketing; that is, PADI gets their affiliation fee and the shops that pay that fee get business "steered" directly to them as a "PADI Approved Operation".
I know many people who have been certified and 'bad air' never enters their minds since they have not been trained to see it as a potential problem. Nobody in my circle even thinks to ask about where the compressor is located, whether it has been properly maintained or whether the air has been tested recently. I have always ensured that the compressor was electric and the air intake was located away from any exhaust sources but only recently learned about the potential for pyrolysis - thanks to some of you well educated people on this board. But what percentage of the diving population will ever take the time to learn such things so that they can be informed enough to vote with their credit card? I fear a very small proportion.
I think the compressor manufactures bear some responsibility for clean air. I note that some of them, e.g., Bauer, offer in-line carbon monoxide monitoring as an "option". In my view, it should be standard equipment. However, until legislation requires that such equipment come with in-line carbon monoxide monitors, I doubt we will see manufactures change their offerings. Of course, even if they did have CO monitors on each machine they sell, one would still have to worry about the operators actually maintaining the CO monitors by calibrating them and changing sensors on time. So, in the end, we are back to square one: the only way to protect oneself from CO poisoning is to personally check each tank. Therefore, I continue to spread the word on this issue and hope you all do as well.
I know many people who have been certified and 'bad air' never enters their minds since they have not been trained to see it as a potential problem. Nobody in my circle even thinks to ask about where the compressor is located, whether it has been properly maintained or whether the air has been tested recently. I have always ensured that the compressor was electric and the air intake was located away from any exhaust sources but only recently learned about the potential for pyrolysis - thanks to some of you well educated people on this board. But what percentage of the diving population will ever take the time to learn such things so that they can be informed enough to vote with their credit card? I fear a very small proportion.
I think the compressor manufactures bear some responsibility for clean air. I note that some of them, e.g., Bauer, offer in-line carbon monoxide monitoring as an "option". In my view, it should be standard equipment. However, until legislation requires that such equipment come with in-line carbon monoxide monitors, I doubt we will see manufactures change their offerings. Of course, even if they did have CO monitors on each machine they sell, one would still have to worry about the operators actually maintaining the CO monitors by calibrating them and changing sensors on time. So, in the end, we are back to square one: the only way to protect oneself from CO poisoning is to personally check each tank. Therefore, I continue to spread the word on this issue and hope you all do as well.
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