"Nitrox" tanks?

[Trixxie]

have not taken my Nitrox class yet, but looking into tank prices and wondering what is the difference in these: *besides the obvious that the first is steel and the 2nd is AL*
For some reason I thought that Nitrox tanks *had* to look a certain way. Can steel tanks be used for EAN? THANKS!

* Brand New for 2006
* Welcome to the next generation in cylinder technology -
High Pressure tanks that are compatible with any regulator.
* Includes Pro Valve-Standard Yoke and DIN Compatible
* FREE Visual Inspection Program (VIP) Included!
* Nitrox Ready up to 40% (the recreational limits of nitrox)
* 3442 PSI
* Includes Self-Draining Tank Boot
* Chromemoly Steel – the same rugged alloy used in aircraft frames for maximum strength-to-weight resilience is required
* Inches in Diameter: 7.25
* Inches in Length: 19.7
* Weight Empty = 27.7lbs
* Buoyancy Full = -9.0lbs
* Buoyancy Empty = -3.0lbs
* Superior buoyancy characteristics vs aluminum – allowing you to shed a few pounds of lead from your weight system
* COLOR: Hot dipped galvanized
* FULL MANUFACTURER´S WARRANTY
________

* FREE Visual Inspection Program (VIP) Included!
* Nitrox Ready up to 40% (the recreational limits of nitrox)
* Includes "Nitrox Only" Sticker
* Includes Pro Valve-Standard Yoke and DIN Compatible
* 3000 PSI
* Proprietary 6061-T6 alloy, a balanced aluminum-magnesium-silicon blend exclusive to Luxfer. This alloy never requires an eddy-current inspection with devices such as Visual Plus, Visual Eddy, or equivalent machines.
* 7.3 Inches in Diameter
* 26.1 Inches in Length
* Weight Empty = 31.7lbs
* Buoyancy Full = -1.9lbs
* Buoyancy Empty = 4lbs
* ´´Real Weight´´ = 35.7lbs
* COLOR: Yellow
* FULL MANUFACTURER´S WARRANTY

 

[pir8]

Same tanks, different cleanliness requirements

 

[Trixxie]

Same tanks, different cleanliness requirements

would it be worth getting a tank I currently own O2 cleaned instead of buying a new tank?

 

[SparticleBrane]

Unless you're going to use it for >40% O2, then you're fine without O2 cleaning it.

 

[Diver Dennis]

That depends on what type of fill the dive shop can give you. Partial pressure fills require O2 clean tanks, no matter what the mix.

 

[countryboy]

Having the nitrox sticker does not get you anything more than a regular tank. If the shop you go to does partial pressure blending, then the tank needs to be O2 clean, not just have nitrox stickers..

If your shop "banks" nitrox, or has a membrane type filter, then the tanks do not need to be O2 cleaned.. Once O2 cleaned you cannot fill from a non "hyperfiltered" system and maintain the O2 Cleanliness.

The big Nitrox stickers don't really mean anything, but some shops require them.. The only "required" sticker is an O2 clean sticker (if you are running PPB Nitrox), Vis Sticker, and a contents sticker (Nitrox / Mix) If just filtered air, many have used tape.

 

[catalina_mike]

You can take off 7 lbs.of weight with the steel one. You can always have the other O2 cleaned for nitrox for a minimal fee normaly. Consult your local dive shop for rates.

 

[countryboy]

would it be worth getting a tank I currently own O2 cleaned instead of buying a new tank?

How does the shop (where you get your gas) do their Nitrox fills? If partial pressure blending, get your tank O2 cleaned.. and keep it clean.

If you have some shops that cannot give you hyperfiltered air, it may be worth having tanks for "regular" air and another set for Nitrox only..

Really depends on the shops you go to.. I have 4 tanks, 2 are O2 cleaned (used mainly for OW stuff, steel) 2 are not (aluminum), use these mainly for pool use, and to loan, etc.

 

[RV]

......... I have 4 tanks, 2 are O2 cleaned (used mainly for OW stuff, steel) 2 are not (aluminum), use these mainly for pool use, and to loan, etc.

So do you prefer steel for O2 clean or did it just work out that way?

 

[Mark Vlahos]

OK, you have some pretty good questions here. I will try to answer simply.

First, these questions and many others will be answered in your Nitrox class.

Steel Vs. Aluminum? Both types of cylinders are commonly used for Nitrox, so if you are considering the purchase of a cylinder don't worry about Steel or Aluminum. Make the choice based on size, weight, durability, or any other factor you like but Nitrox is safe in either.

If you already own a cylinder you can pay to have it cleaned for "Oxygen Service," this will probably cost around $50 and needs to be done every year, usually along with the visual inspection. When a cylinder is cleaned in this manner the cylinder interior is cleaned, and the valve is cleaned and rebuilt using special materials that are designed for use in a high oxygen content and high pressure environment. Things like lubricants and O-rings are replaced. Now, having just told you about cleaning for oxygen service this may only be a factor if the place you will be getting the Nitrox uses a method called Partial Pressure Blending.

With Partial Pressure Blending you start with an empty cylinder and first add pure oxygen to a given pressure, then hyper clean air is added up to the desired end pressure. Since the pure oxygen is added first the interior of your cylinder is exposed to this pure oxygen and needs to be cleand to prevent fires. There are some other ways to put Nitrox in to your dive cylinder. Most of the other methods do not actually put pure oxygen in to your cylinder in concentrations higher than the desired mixture you want. With these filling procedures many shops do not require that your cylinder be cleaned to the stringent "Oxygen Service" standard.

The problem is that some of these methods for putting Nitrox in to your cylinder are more expensive and less flexible than Partial Pressure Blending so not all shops use them.

The best thing for you to do is to take the class, then figure out what method the shop you will be getting fills from uses, and make sure your cylinders are ready for whatever system that shop uses.

If you need to have your cylinders cleaned for Partial Pressure Blending, you need to make sure that every fill you get uses hyper clean air, normal air can have trace amounts of hydrocarbons, these trace amounts can be dangerous. It is your responsibility to keep the cylinder clean for the entire time you get Partial Pressure Blend fills.

Some shops require the large NITROX bands to be placed on your cylinders, while others do not seem to care.

Good luck,

Mark Vlahos