Converting tanks to Nitrox

[oxyhacker]

Thanks for the plug!

I got to say, I am increasingly feeling the PP mixing just isn't the way to go for shops, and it's time to send O2 cleaning the way of buddy breathing and J-valves. Any shop that is serious about selling nitrox really ought to bite the bullet and do it right, and spare their customers all the hassle and expense of having tanks cleaned, and then worrying about recontaminating them when they can't find a clean fill.

Don't get me wrong - PP mixing is great for the homebrewer, and anyone not turning out volume. But just about every shop I know that got cautiously into nitrox ends up selling a lot more than they thought they would, and the easier it is to get into the customers tanks, the more they sell - expecting the customer to leave the tanks so they can be PP filled is micky mouse.

It can be argued that PP mixing is a good way for a shop to test the waters, and get into nitrox without too big an investment, but the thing is, if they set up for premix from the start, it doesn't have to cost all that much more than setting up for PP mixing, and as they expand, none of the expense will be wasted (the way it is going from PP to premix). A hyper filter and commercial grade whip cost about $1500-2000, for not much more a diveshop could buy a can of EZ-1000 compressor oil and a four-tank cascade, build an OXY HACKER continuous mixer, and start banking 40%.

So I regard having tanks commercially O2 cleaned as a last resort these days, for when no shop can be found nearby that will pump premix. I'd I'd grumble long and hard while having it done about how the shop really ought to get with the times.

Originally posted by roakey
I mentioned The Oxygen Hackers Companion. This is an excellent book, and that’s putting it mildly. It’ll teach you everything that a mixing course will teach you and much, much more. If you’re the least bit interested in the nuts and bolts of Nitrox, I HIGHLY recommend you buy it, it’s worth far more than the $35 you’ll pay for it.

To order, see: http://www.airspeedpress.com/

 

[ssscuba]

I have to agree with oxygen cleaning and dive shops. I have to think that one the tank leaves my shop there is no way for me to know its staying clean and dry inside. I get plenty of tanks in the shop that have water in them from being empty. I do have home brewers that do their own O2 cleaning and I try to help them do it, but I will never assume a tank o2 clean regardless of the sticker and siply do not do partial pressure to protect myself.

David

 

[MikeFerrara]

I would agree with oxyhacker except in our case. As an inland dive shop (not near a dive site) and since all the dive sites (deeper than 25 ft) pump nitrox the only gas we sell is to our students and a few local tech divers. Almost everything I mix is over 50%. PP blening is just the ticket for us. If I had bunches of divers walking in for nitrox I would continuouse blend for certain.

 

[tinman]

Ontario Diver once bubbled: "If you are diving Nitrox, a popular method is partial pressure blending. Using this method - pure O2 is pumped into your tank first and then air is added. If your shop uses this method (and all of those I've seen in Ontario do!!!) your tank and yoke must be O2 Cleaned and serviced."

Tam Peterborough uses partial pressure and Adventure Divers uses continuous blending for those that prefer one vs. another method.

 

[Spectre]

The shops around here that bank 40% charge so damn much that it's worth it to get tanks O2 cleaned so you can get fills from the partial pressure blending shops [a difference of $10 a tank].

So now I have my old AL80s for when I need fills down where I can't be sure the air is hyper-filtered....