Air in eanx marked tank?

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buckled plates

Contributor
Scuba Instructor
Divemaster
Messages
96
Reaction score
71
Location
Virgina
# of dives
500 - 999
The Captain Hook's dive shop in Big Pine Key, FL will not fill a tank with air if it has a nitrox sticker attached to it. I've never encountered this before. The shop claims it's a DOT regulation. If that's the case, then every other dive shop along the east coast I visit apparently is violating DOT regulations. Is this correct?
 
I cant say for sure but the sticker is to say nothing but nitrox in the tank. that prohibits trimix and other gasses. the air in it is to be nitrox air or hyper filtered E grade air and not say D or E as may be used in other applications with low O2 content. Originally (this may be incorrect also) the plaquard was used for deco gas when the tank was used for nitrox greater than 40% That level of O2 demanded clean air in the mix and that less than 40% was treated as air. I have never seen anyone refuse to fill the tank solong as they have hyp E air to put it. after all 20.9 air is nitrox. There is a rule that says the tank can not be used for other than it is marked for. You cant put CO2 in a tank that is marked for air. Yet no scuba tank is marked for air and yet shops see a difference between air and nitrox that is not covered by the vis sticker. Somewhere someone decided that nitrox is 23% and greater and there for nothing but 23.5% or greated can go into the nitrox banded tank. The humorous side of this is that they will top off a tank with say 40% in it with hyp E air to reduce the mix to something lower. GO FIGURE.

The question I would ask is .... are they filling regular air tanks with less than HYP E air. Some shops do that. The have banked air of Grade E to get a nitrox fill they take it from another whip that is sourced by additional filtering.

No matter what you cant argue with the owner. If he cant give you what you want in a reasonable manner then you and your money walk across the street.
 
I cant say for sure but the sticker is to say nothing but nitrox in the tank. that prohibits trimix and other gasses. the air in it is to be nitrox air or hyper filtered E grade air and not say D or E as may be used in other applications with low O2 content. Originally (this may be incorrect also) the plaquard was used for deco gas when the tank was used for nitrox greater than 40% That level of O2 demanded clean air in the mix and that less than 40% was treated as air. I have never seen anyone refuse to fill the tank solong as they have hyp E air to put it. after all 20.9 air is nitrox. There is a rule that says the tank can not be used for other than it is marked for. You cant put CO2 in a tank that is marked for air. Yet no scuba tank is marked for air and yet shops see a difference between air and nitrox that is not covered by the vis sticker. Somewhere someone decided that nitrox is 23% and greater and there for nothing but 23.5% or greated can go into the nitrox banded tank. The humorous side of this is that they will top off a tank with say 40% in it with hyp E air to reduce the mix to something lower. GO FIGURE.

The question I would ask is .... are they filling regular air tanks with less than HYP E air. Some shops do that. The have banked air of Grade E to get a nitrox fill they take it from another whip that is sourced by additional filtering.

No matter what you cant argue with the owner. If he cant give you what you want in a reasonable manner then you and your money walk across the street.
There isn't exactly a "down the street" for 15 miles.

The folks at Captain Hooks are very nice. They know what they were taught, and they were taught by the nice folks at Quiescience. They didn't all learn the lesson.

I would ask them for Nitrox 21. Tell them you are mixing it with the exact amount of nitrox 32 left in the tank to make nitrox 24 so you can make a dive to 155 feet.

If that doesn't work, see Bob and plead your case to him directly. I would be happy to intercede on your behalf.
 
Yep, but of course sometimes it's not as easy as going across the street. It's also hugely expensive and inconvenient for friends and customers whose tanks have had nitrox stickers removed if the same shop won't fill them with a nitrox mix unless the tank's been inspected and approved for nitrox. I work with a tech dive shop in Virginia Beach (at it for many years). They told me Captain Hook's is wrong. As Wookie suggests, I'm going to asked them for a 21% nitrox fill. They'll be happy with that, no doubt, charging me nitrox for air. Oh, boy....
 
Nitrox stickers are dumb and it's super annoying that dive shops still insist on them.

I tell mine to leave it off, the only indication that it has been O2 cleaned should be on the inspection sticker.
 
Then you have to pay the extra $5 or so.
Better than no fill :)

EDIT: And to get a little serious, if your tank is O2 clean, you might prefer that the gas you fill is nitrox quality. I have no idea what O2 cleaning costs on your side of the pond, but if you fill air which doesn't fulfil the demands for nitrox quality you have to O2 clean your tank again before PP blending nitrox.

IF nitrox_cost*number_of_fills > price_for_O2_cleaning
THEN ask_for_nitrox21_and_pay_the_price
 
Yep, but of course sometimes it's not as easy as going across the street. It's also hugely expensive and inconvenient for friends and customers whose tanks have had nitrox stickers removed if the same shop won't fill them with a nitrox mix unless the tank's been inspected and approved for nitrox. I work with a tech dive shop in Virginia Beach (at it for many years). They told me Captain Hook's is wrong. As Wookie suggests, I'm going to asked them for a 21% nitrox fill. They'll be happy with that, no doubt, charging me nitrox for air. Oh, boy....
Captain Hooks does allow an O2 clean VIP sticker instead of the massive nitrox band. I have both the O2 clean sticker as well as a nitrox chevron on the crown and they fill mine just fine. Of course, my wife works there.
 

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