View Full Version : O2 service vs 2.5yr service
Nick Kay
11-04-2003, 17:38
Just put some of my cylinders in for service/O2 service or just O2 service.
If you have an O2 clean (Nitrox) cylinder serviced, does that nullify the O2 service?
It used to be simple - O2 service every year and (for simplicity's sake) get the biennial service done at the same time on alternate years...
andy botten
11-04-2003, 20:16
If you have an O2 clean (Nitrox) cylinder serviced, does that nullify the O2 service?
That depends if they clean it at the same time, at a cost ;-)
It used to be simple - O2 service every year and (for simplicity's sake) get the biennial service done at the same time on alternate years...
Chances are to keep (y)our cylinders O2 clean (y)our cylinders will end up going through the vis/hydro cycle every other year.
Whilst it is officially a harmonisation with Europe; the reality is nothing has changed. Who wants a cylinder tested between April & October.
We are all going to get our cylinders tested early.
Nigel Hewitt
11-04-2003, 21:59
Whilst it is officially a harmonisation with Europe; the reality is nothing has changed. Who wants a cylinder tested between April & October.
We are all going to get our cylinders tested early.
I fear you are right. I just got some visualed 18 months from their new stamp date as I don't want a few weeks lay-off in August. I think they'll get hydroed early in 2005 for the same reason so I get no benefit from the 6 month extension.
However I've given up on annual oxygen clean. I tend to blend myself so all I ask for is clean air. They will get cleaned every two years on the test.
nigelH
Whilst it is officially a harmonisation with Europe; the reality is nothing has changed. Who wants a cylinder tested between April & October.
Err we do. Maybe time for some maths.
You have extended the testing by 0.5 years, but with no extra
cost to you. Based on say a ?20 charge, your actual saving
is ?4. Even if we say an O2 test is ?8 per annum your 02 test
for that extra 6 months has cost you ?4 (the other ?4 is for
the next 6 months). Result nil cost / break even.
But if you play it right its'a big bonus. Our club has a mix of
Air & Nitrox with common renewal dates (O2 & Test at the same
time). Bit of cylinder management as it gets towards winter
and you can easily save some dosh. Still better is to negotiate
with your friendly testing station, who may even wave 6 months
testing. Reason that's a may is beacuse we are gioing to have
to wait another 2-2.5 years to find out.
Rgds
TerryH
michael smith
14-04-2003, 09:24
Hello, by giving up on the annual oxygen service because you fill the oxygen yourself you are running a risk. The shop that you get your air from will likely be using a double filtered compressor. Even with the double filter some contamination enters the cylinder over time. Accepted practice is to get the cylinder cleaned each year, to ensure the contamination level does not become too high. By extending this time to two years, you are taking a risk with yourself and where you get your cylinders filled. I would trust that you have informed the filling station what you are doing. Which begs the question of how would they give you a Nitrox mix, which requires you to analyse it and sign for it, without the correct stickers on it. If anyone was to take a cylinder in pretending it is an air cylinder to get it topped up. They would be putting the filling station personnel in danger.
I would ask you to think of the risks you are taking, for saving ?20 - 30 each year per cylinder.
Regards Mike
john kendall
14-04-2003, 10:24
Hello, by giving up on the annual oxygen service because you fill the oxygen yourself you are running a risk. The shop that you get your air from will likely be using a double filtered compressor. Even with the double filter some contamination enters the cylinder over time. Accepted practice is to get the cylinder cleaned each year, to ensure the contamination level does not become too high.
Go on Nigel, show him the maths :-)
John
Dominic Humphries
14-04-2003, 11:18
Go on Nigel, show him the maths :-)
Or just gloat about the way you don't add air to an Oxygen cylinder..
iainmsmith
14-04-2003, 16:13
:=Go on Nigel, show him the maths :-)
:=
Or just gloat about the way you don't add air to an Oxygen cylinder..
Do dedicated oxygen cylinders not need annual O2 cleaning? Logically, there is no reason that they should, but logically (and legally), we don't need annual O2 cleaning for any nitrox tank anyway...
Iain
Do dedicated oxygen cylinders not need annual O2 cleaning? Logically, there is no reason that they should, but logically (and legally), we don't need annual O2 cleaning for any nitrox tank anyway...
This was discussed on ukrs recently with reference to first aid O2
Nigel Hewitt
14-04-2003, 19:56
Go on Nigel, show him the maths :-)
I can't be bothered to write it all out but in another forum we calculated how much petrol it needed to detonate in pure oxygen to take a tank from its working pressure to its test pressure and it was about 20ccs. 20ccs of petrol exceeds the lethal dose if inhaled. A tank contaminated to the extent that it would kill the diver would not burst.
And matching another post I assume my Air Products oxygen Js are uncontaminated so my pure oxygen tanks are safe. Nobody else puts oxygen in my tanks and these days all I get from the shop is the twin 10/300s filled with clean air which I can decant from and also use to power the booster.
I do know what I'm doing. I have blender tickets from IANTD and TDI so I know what they recommend and when I am being the shop blender I enforce those rules apologetically but firmly. Personally I think O2 cleaning was essential when Nitrox was young, so to speak, but annual cleaning is getting to be past its sell by date.
nigelH
I can't be bothered to write it all out but in another forum we calculated how much petrol it needed to detonate in pure oxygen to take a tank from its working pressure to its test pressure and it was about 20ccs.
See link below to your original post.
The whole thread is worth reading as it covers similar ground to this one but in a lot more detail.
Annual O2 cleaing is a hang over from the c****y old compressors we had to use - with a modern compressor having it done every 2.5 years would be just as safe as every year, after all who is to say the contaminated fill is not going to be the one straight after it is cleaned.
Pete
iainmsmith
15-04-2003, 18:35
:=Do dedicated oxygen cylinders not need annual O2 cleaning? Logically, there is no reason that they should, but logically (and legally), we don't need annual O2 cleaning for any nitrox tank anyway...
:=
This was discussed on ukrs recently with reference to first aid O2
I should have been more specific - I was thinking of scuba cylinders, used for decompression, which are permanently labelled for "OXYGEN" and never have anything other than decanted/boosted O2 put in them.
As they never get a chance to get hydrocarbon put into them, there is no reason to clean them annually, right?
Iain
:=:=Do dedicated oxygen cylinders not need annual O2 cleaning? Logically, there is no reason that they should, but logically (and legally), we don't need annual O2 cleaning for any nitrox tank anyway...
:=:=
:=
:=This was discussed on ukrs recently with reference to first aid O2
I should have been more specific - I was thinking of scuba cylinders, used for decompression, which are permanently labelled for "OXYGEN" and never have anything other than decanted/boosted O2 put in them.
As they never get a chance to get hydrocarbon put into them, there is no reason to clean them annually, right?
Do they _need_ it? No
Do you have to get it done? probably due to the dive industry cartel
If it's a worry, do it yourself. It's not exactly complicated. I've never been trained in the black art that is O2 cleaning, yet I was able within half an hour to clean a tank on my won? Am I some diving prodigy?
No. It's because it pays for dive centres to make out like it's really hard to do, and that the chemicals required are sourced from mountain springs, high in the himalayas. In reality, I'm told you can boil down oranges to make a very effective chemical for O2 cleaning the inside of tanks. Of course, I can't see your LDS volnteering to fill it with O2, but then you haven't paid them for the pleasure!!!
If it's a worry, do it yourself. It's not exactly complicated. I've never been trained in the black art that is O2 cleaning, yet I was able within half an hour to clean a tank on my won? Am I some diving prodigy?
Nope, but how do you suggest the filling station is going to
know you did it right? Unless you have your own compressor,
bank, pump, O2 etc.etc. it's all pretty academic once you have
to actually have to get it filled again.
I can just see the proliferation of personal O2 clean stickers.
Yours can even have a picture of a Orange on it! The man from
Del Monte, he says O2 clean!
Besides everyone knows that they come from the French Alps.
Just the right level of acidity. The molecules do a Gallic
shoulder shrug and the dirt falls off.
TerryH
Best thing about France? Gives you somewhere to sleep while
your travellling to Spain.
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