View Full Version : 15ltr cylinder White or Yellow
Rusty Nuts
22-11-06, 17:14
Hi can anybody tell me the diference between a white or yellow cylinder apart from the colour.
Also what is the best size some say 12ltr others say 15ltr, Im a big lad dose it depend on what you can carry?
Russell.
Hi can anybody tell me the diference between a white or yellow cylinder apart from the colour.
Also what is the best size some say 12ltr others say 15ltr, Im a big lad dose it depend on what you can carry?
Russell.
No It depends on how much you use.. what size do you use just now? If the size you have just now is ok there is no point getting a bigger one. As for the colour it should be black and white triangles on top. this Indicates breathing air.
Hi can anybody tell me the diference between a white or yellow cylinder apart from the colour.
Also what is the best size some say 12ltr others say 15ltr, Im a big lad dose it depend on what you can carry?
Russell.
work out your average surface air consumption rate (SAC) to decide what size cylinder you require.
your SAC rate will drop when you become more comfortable in the water.
as ding suggests, the HSE legislation requires the top of the cylinder should have black & white quadrants.
the rest of the cylinder can be any colour, but a bright colour is obviously better.
for example, mine are black! :rolleyes:
Further reading...HSE website, page 2.
http://66.102.9.104/u/HSEC?q=cache:7SMJzkC9Bl8J:www.hse.gov.uk/pubns/dvis3.pdf+diving+cylinder+identification&hl=en&ct=clnk&cd=1&ie=UTF-8
Gas Guzzler
22-11-06, 22:59
I currently have 2 x 12 liter, but I'm going to get a 15 liter as I sometimes get short of gas if diving to > 40 metres.
If you can get 60 minutes from a 12 with 50 bar in reserve, what's the point in the extra weight of a 15?
Also a 15 has a greater change in buoyancy as air is used up
GG
Also a 15 has a greater change in bouancy as air is used up
GG
And you had the cheek to comment on Ding's spelling......
As for making a 12l last 60 minutes, I distinctly remember motioning to you in the Maldives to 'get up the reef' (gesticulating upwards wildly while glaring at buddy) when you were down to 100 bar after 30 minutes....there was no way I was being deprived of a full 60 minutes!
dive granny
22-11-06, 23:18
[QUOTE=Claire;4241]And you had the cheek to comment on Ding's spelling.....
Thought that was my job! Te He:D
Gas Guzzler
22-11-06, 23:22
Enjoy it while you can. I've got the spell checker working.
I'm sure I should be making smutty comments about lasting 60 mins.......
GG
If you can get 60 minutes from a 12 with 50 bar in reserve, what's the point in the extra weight of a 15?
more redundancy.
all to do with dive planning.
most people jump in & come back with 50 bar...all fair & well if everything goes right.
rule of thirds... 1/3 in, 1/3 out, 1/3 in reserve = 77 bar from a 232 fill.
call it 75 for easy counting.
this 75 bar will help get not just yourself, but also your buddy out of trouble should the situation arise.
you could loose as much as 20 bar in an instant with a free flowing reg.
if your venturing into the realms of 30m-40m, dive planning is a whole new ball game.
dive safe,
stewart
Rusty Nuts
23-11-06, 15:40
How do you work out your average surface air consumption ?
Thank folks for all the advice i think the best way to find out what's best for me is to try a dive with 15ltr.
Russell.
iwmcarthur
23-11-06, 15:51
SAC (Surface Air Consumption) aka RMV (Respiratory Minute Volume) can be worked out as follows:-
Go to, for example, to 20m (ie 3bar). Take note of your cylinder pressure then gently swim about at 20m for 10mins and take a note of your cylinder pressure again. Then do the following calculations (underwater if the dive is really boring !!)-
End pressure - start pressure = bar of gas used, say 50
Multiply by cylinder size, say 12litres gives amount of gas used = 600litres
Divide by depth you were at (in bar) = 3 giving 200 litres
Divide by time you were at that depth (in mins) = 10 giving 20
Your RMV or SAC would then be 20litres a minute.
Hope this helps:)
the HSE legislation requires the top of the cylinder should have black & white quadrants.
Thats only for commercial use
as a sports diver doesn't have to be quaterted
the HSE legislation requires the top of the cylinder should have black & white quadrants.
Thats only for commercial use
as a sports diver doesn't have to be quaterted
your absoutly right.
however we will more than likely soon be inline with the european standard & its more practical to have them than not.
Hi can anybody tell me the diference between a white or yellow cylinder apart from the colour.
Also what is the best size some say 12ltr others say 15ltr, Im a big lad dose it depend on what you can carry?
Russell.
No, it depends on what you use, and if you want to stay under longer (also govened by your ndl's)
I use 15 as I have the air consumption of a 40 year old diesel engine (although I'm working on that by running 5 times a week)
Colour dont matter, but if your using Nitrox you need proper marking. PADI have set rules for this and I'm not too sure about the other diving outfits.
I would say go for the 15l.
I currently have 2 x 12 liter, but I'm going to get a 15 liter as I sometimes get short of gas if diving to > 40 metres.
If you can get 60 minutes from a 12 with 50 bar in reserve, what's the point in the extra weight of a 15?
Also a 15 has a greater change in buoyancy as air is used up
GG
Lynsey is selling one
ask her on friday
Lizardland
07-12-06, 13:24
your absoutly right.
however we will more than likely soon be in line with the European standard & its more practical to have them than not.
Yeah with those stupid dedicated nitrox valves they want us to put on them as well:mad:
Like Stewart said its better to get it now than change later...
Of course it also depends what sort of diving you are doing... I have a friend who I swear sometimes comes up with more air than he went down with... yet he got a 15litre cylinder for when he was instructing at a Padi school.
Why? because he couldn't be bothered changing cylinders and for the sort of training bimbles he was taking them on he could get three or four dives out of a cylinder ;)
Mind you I also dived with a Brit abroad who would regularly have a consumption rate below 10 lit/min average :eek: ("Sinky" Sinclair in case anyone knows him), almost as wierd as the superfit instructor at the same centre who wore twin 12's because he was nearer to 40 lit/min relaxed and happy :confused:
Just goes to show why we should never calculate on an "average" figure ;)