HP tanks and Nitrox

[Ari]

A question to all of you guys who are brewing mixtures.

Is there a problem with using HP, 300 bar, tanks for Nitrox or, for that matter, other mixtures?

Ari

 

[SDAnderson]

No problem.

Steven

 

[Ari]

Thanks for the reply. Can you please elaborate on your answer?

What mixing method do you use and is there a difference in safety procedures when compressing mixtures to HP (300 bar) tanks in comparison to compressing to LP (200-230 bar) tanks?

Ari

 

[TheAce]

Hi Ari..

According to what I have seen around, what is called LP is usually reffered to 2400psi +/- (approx 160bar), at times those tanks carry the + sign that means they can be filled 10% more. HP is reffered if I am not wrong to 3000psi and over (200bar+). But again, I might be wrong.

BTW, I have seen a few of those LP tanks in quite a few diving centeres in Israel filled to 200-210bar which is EXTREMLY dangereous. You can find them in Meduza rentals for example....

Ari.

 

[pescador775]

Ari, Ari, so many questions, so little time. You want an elaboration on 'NO'? There just has to be a problem out there to jump on, right?

Well, there are technical issues with jacking oxygen and air to VHP. For one thing, the PP mixer might not find it convenient or practical to prepump 600-900 psi of O2 unless he has a booster or scavenger pump. The blender might wonder whether his oil pumped compressor is safe while pumping NITROX at such high pressures. I'm hearing that it's OK with special oil like EZ 1000. If he feels otherwise, he might opt to use a dry lubed or water lubed compressor, or limit blends to 32%. Also, a hopcalite catalyst filter would be high on the list. My understanding is that folks (Omar?) bank Nitrox to VHP (very high pressure) without any special problem other than careful management of the normal NITROX control issues which apply at lower pressures.

If there was a single word or phrase that you didn't instantly recognize and understand, suggest you buy V. Harlow's book, Oxygen Hacker's Companion.

 

[No Vis No Prob]

Gimme a break Ace. When I'm in NFL, if I get less than 3600 on my lp's, I complain. I ususally get 3900 wherever I go. These tanks have a burst pressure of 6000 #'s, and a cycle rating of 10000 turns @ 4000 #'s. I can't understand why there is so much voodoo and superstition surrounding DOT ratings.

 

[Compressor]

Burst Pressure of 6000!!!!?????

 

[wazza]

Its doesn’t matter if the tank is low pressure or high pressure
Low pressure tank are filed for 200 to 220 bars
and high ones are filed for 250 bars to 300 max
And it doesn’t matter what mix is inside the tank .
what ever tank u r using, if u want to fill Nitrox make
sure the tank Should be O2 clean that is all.
or it will :boom:

 

[pescador775]

Guess what, a nitrox tank does not necessarily have to be O2 clean. Depends on what method is use to mix the gas and/or fill the tank. Looks like you bombed instead.

:bonk:

 

[SimonN]

Is there a problem with using HP, 300 bar, tanks for Nitrox or, for that matter, other mixtures?

Sort of:

1) The ideal gas laws stop working around 250 bar, so if using partial pressure blending, it can be harder to get the right mix.

2) Obviously, you need higher pressure in the banks to fill 300 bar cylinders to their working pressure. May or may not be a problem, but the higher the WP the more likely it is to be a problem.

According to what I have seen around, what is called LP is usually reffered to 2400psi +/- (approx 160bar), at times those tanks carry the + sign that means they can be filled 10% more. HP is reffered if I am not wrong to 3000psi and over (200bar+).

Depends where you are in the world.

In Europe and Australia/NZ (and probably some other locations) LP is 232 bar (~3400 PSI) and HP is 300 bar (~4400 PSI).

AFAIK in the US, LP is 2400 PSI (~160 bar), HP is 3000-3300 PSI (~200-220 bar).