Short fills on deco bottle

[JohnN]

I'm finishing up my TDI Decompression Procedures class, purchased an AL40 bottle from my LDS and asked for an 80% fill.

After bringing it home, I'm only seeing 2500 PSI (3000 PSI bottle). I asked the shop and was told this was 'normal', the reason being that their O2 bottles only come in at 2250 PSI when full.

Am I being fed a story (and should find another shop) or is this just the way it is?

 

[rongoodman]

That's the standard fill I see on the O2 bottles at work(EMS). Had they filled your bottle to 2250 psi with O2, though, it should have been at 3000 psi after being topped off with air. Look for a shop with a booster.

 

[wedivebc]

That is not uncommon when a dive shop does not have a booster. Basically they would have to tap a fresh O2 T-cylinder every time someone asks for a 80% fill. You need to either accept it or find a shop that owns a booster.

 

[GrimSleeper]

O2 is usually supplied at 2250psi, at least it is when I buy it from B.O.C., so assuming the shop doesn't have a booster pump and are cascading their supply bottles, they'd only be able to give you a 3000psi fill of 80% when their supply bottles are completely full.

As long as they're charging you per cubic foot of O2 used in blending, it's only an issue if you need more gas than they can give you in your 40. If you're diving in Oregon I'd guess your SAC rate is pretty high (mine certainly is in cold water), so if that's the case your options are to either find a shop that has a booster if the extra 7cf or so will get you where you want, or start using an 80 for deco. I use al80s for 50% and O2, because I'm a big fan of blending 50 once and getting two or three dives out of it (i.e. I'm lazy...), and I don't like leaving pure O2 in decos at very high pressures.

Of course, if you used 100% O2 for deco instead of 80% you wouldn't need as much gas... :cool2:

 

[Dive-aholic]

I get oxygen supply bottles at 2400 psi usually, sometimes 2600 psi if they filled them slowly and cold. The suppliers won't fill them any higher. Without a booster you can't get it any higher and boosters cost quite a bit. A brand new oxygen compatible booster runs $5000-8000 depending on the model. Most shops won't spend the money on that for a few fills a year. That being said, I know there are shops in Oregon that do have boosters and can fill your O2 bottle to 3000 psi even with 100% O2. You just may not be close to any of those.

 

[James R]

Anothe good reason to get lp45 steel tanks for deco bottles.