Nitrox Fills

[cth6]

What do I have to look for when it comes to Nitrox fills?

I currently have two O2 cleaned tanks and valves.

*My current LDS uses partial pressure mixing.
*My West Palm LDS uses partial pressure mixing.
*A potential LDS (much closer to the house) uses oxygen compatable air mixed with O2 fed into the compressor.

My current LDS and Nitrox Instructor (Manager of the LDS) stated that if I don't use partial pressure mixing and Grade E+ air the fills could prevent partial pressure mixing.

Can I go back and forth between different fill techniques?

What is the difference in the grades of air; Grade B, Grade E, and Grade E+?

 

[TwoTanks]

If you put air which is not oxygen clean, into an oxygen clean tank, then the tank is no longer oxygen clean and should not be used for partial pressure blending. Then the tank must be oxygen cleaned before partial pressure blending.

Partial pressure blending is becoming less common for recreational blends (in my opinion), and in the future it will probably be even less common, but for now you should only use your tanks one way or the other.

TT

 

[Curt Bowen]

What do I have to look for when it comes to Nitrox fills?

I currently have two O2 cleaned tanks and valves.

*My current LDS uses partial pressure mixing.
*My West Palm LDS uses partial pressure mixing.
*A potential LDS (much closer to the house) uses oxygen compatable air mixed with O2 fed into the compressor.

My current LDS and Nitrox Instructor (Manager of the LDS) stated that if I don't use partial pressure mixing and Grade E+ air the fills could prevent partial pressure mixing.

Can I go back and forth between different fill techniques?

What is the difference in the grades of air; Grade B, Grade E, and Grade E+?

All are just fine to use.

A. Partial Pressure: Fill empty cylinder with pure oxygen to Xpsi and top off with filtered air from compressor or banked gas. Your scuba cylinder needs to be O2 clean because it is exposed to oxygen percentages above 40%.

B. Continuous Gas Blending: Oxygen and air are run through a compressor at percentages below 40% (Nitrox stick http://www.envirodive.com ) and through a filter system straight into your tank or bank cylinders.

Both are just as clean, but you do not need to oxygen clean your cylinder for B. Continuous Gas Blending because your cylinder is never exposed to Oxygen percentages above 40%.

Your cylinder does NOT become contaiminated by system B. if it has been oxygen cleaned for partial pressure filling.

 

[cth6]

Your cylinder does NOT become contaiminated by system B. if it has been oxygen cleaned for partial pressure filling.

With the above statement are you talking about the fill station being oxygen cleaned or my tanks?

 

[Curt Bowen]

With the above statement are you talking about the fill station being oxygen cleaned or my tanks?

If you have cleaned your cylinder for partial pressure filling, it will not be contaminated by also filling it with a continuos blending system afterwards.

You can use either system after your cylinder has been cleaned.

If your cylinder has NOT been cleaned you can only use the continuos blending system.

 

[padiscubapro]

If you have cleaned your cylinder for partial pressure filling, it will not be contaminated by also filling it with a continuos blending system afterwards.

You can use either system after your cylinder has been cleaned.

If your cylinder has NOT been cleaned you can only use the continuos blending system.

Curt,
Its not as simple as that.. Especially if "a" you are a dive shop and "b" if you loan anyone your cylinders.

If you use ANY mix above 23.5 % with Luxfer or Catallina cylinders , or use Thero Valves, you must main the systems as oxygen clean regarless of method of filling. The official policies of these 3 manufacturers state the components must be maintainded for oxygen service.

I have not been able to locate any Official policies from Sherwood Scuba, Faber or PST

The most recent policy of thermo also states 40% is the max and doesn't recommend PP blending with thier valves

http://www.catalinacylinders.com/oxycomp.html
http://www.thermovalves.com/oxygen_enriched_air.htm
http://www.luxfercylinders.com/support/bulletins/20040723.shtml

ANy store that fills these products or someone who rents/loans a component to others that this isn't followed is risking a potential liability issue.

 

[Curt Bowen]

Curt,
Its not as simple as that.. Especially if "a" you are a dive shop and "b" if you loan anyone your cylinders.

If you use ANY mix above 23.5 % with Luxfer or Catallina cylinders , or use Thero Valves, you must main the systems as oxygen clean regarless of method of filling. The official policies of these 3 manufacturers state the components must be maintainded for oxygen service.

I have not been able to locate any Official policies from Sherwood Scuba, Faber or PST

The most recent policy of thermo also states 40% is the max and doesn't recommend PP blending with thier valves

http://www.catalinacylinders.com/oxycomp.html
http://www.thermovalves.com/oxygen_enriched_air.htm
http://www.luxfercylinders.com/support/bulletins/20040723.shtml

ANy store that fills these products or someone who rents/loans a component to others that this isn't followed is risking a potential liability issue.

a. He is not a dive shop, we are not speaking about dive shop regulations and

b. I do not loan my tanks out

 

[cth6]

So my valves on my fabers have NITROX labels on them. Does this mean that the are OK for parital pressure mixing?

 

[murphdivers286]

What about CO2 filtered air to make nitrox?

 

[Uncle Pug]

What about CO2 filtered air to make nitrox?

No such critter in the barn or on the range.