What is a safe pressure?

[scubatexastony]

Just courious if anyone had the exact data or else my findings are wrong. I weighed one of my AL80s with 2000psi remaining, 40 lbs. The weight of the other with 3000psi, 44 lbs. Are the tanks different, yes, one a cat and the one a lux, but me figures I get the skinny from someone in the know.

 

[roakey]

Air & Nitrox weighs about 1 pound for every 13cf. Trimix weighs less.

So an AL80 with air/Nitrox will swing about six pounds from full to empty, or 2 pounds for every 1000 psi.

Roak

 

[Mario S Caner]

Originally posted by scubatexastony
Just courious if anyone had the exact data or else my findings are wrong. I weighed one of my AL80s with 2000psi remaining, 40 lbs. The weight of the other with 3000psi, 44 lbs. Are the tanks different, yes, one a cat and the one a lux, but me figures I get the skinny from someone in the know.

Each cuft of air weighs about .081lbs so an 80 filled with 3000psi weighing 44lbs (37.5lbs empty) being your full cylinder, the 40lbs cylinder at 2000psi only had about 53cuft of air in it. The 27cuft difference should only make a 2.2lb difference... so there is some kind of a discrepency here, but who's to say all of the math and weights are correct to begin with eh!

There are plenty of guys around here with calculators in their pockets that probably have an idea or two... hehe, let's see what they have to say.

 

[scubatexastony]

maybe my scales were off a bit, and too, like i said, one was a cat and the other a lux. the full one was the cat, also the cat has a clear coat on it so too many varibles to be exact. Thanks so much for the info though.

 

[turnerjd]

Originally posted by 100days-a-year
turnerjd...sorry to hear al. is so expensive there.In the states al. is roughly 1/2 the cost of steel,with HP being a little more costly than LP.I assume the cost is due to sheer volume.A recent foray to local shops turned up these prices out the door .Al80 $150,Lp80$300,Hp80 $350.Sorry to hear about the rules there.Must be drag to travel.Our biggest worry is getting fills done before we return from shopping.

http://www.divebag.co.uk/tanks.htm

I think that our steel tanks are the same price / cheeper than your aluminium tanks!!

Steel are the rule, simply because most of the diving here is done in a minimum of a 5mm two piece suit or a drysuit. There is no advantage in having a lighter aluminium tank.

As for travel - europeans don't tend to do the long distance journeys that are (i believe) common in the US. I would say that if you are going anywhere by car it would be within your own country, and if you are flying, you get a tank at the other end, so travelling is a non issue, However, with the current big bussiness trend for 'european integration' - ie moving you wherever *they* want within europe, it is a big issue when you have to replace 5 tanks!

Jon T

 

[100days-a-year]

Jon T,killer prices,do they include VIP,Valves etc out the door taxes etc.I realise most of the diving there is cooler than here.I lived and travelled Europe and Middle East as a child and sailor in the US Navy.Given the latest exchange rate of $1.47 to 1 Pound it would be nearly worth the shipping on some of them.

 

[turnerjd]

Originally posted by 100days-a-year
Jon T,killer prices,do they include VIP,Valves etc out the door taxes etc.I realise most of the diving there is cooler than here.I lived and travelled Europe and Middle East as a child and sailor in the US Navy.Given the latest exchange rate of $1.47 to 1 Pound it would be nearly worth the shipping on some of them.

Yes, that will include

Tank,
Valve
Boot (as they are steel)
Hydro test (as they are new they come with a full hydro)
17.5% Value Added Tax (VAT - a bit like the US sales taxes)

However, You CAN'T ship them to the US. Well, You can, but they won't be any use to you. All the tanks there are to BS5045, OR EN144. None of them will have the necessary DoT stamps on them for you to i) get them filled, and ii) get them inspected in future.

Jon T