Bad memory? O2 Clean required for less than 40% nitrox

[tursiops]

You can’t clean them just once. You need to have them cleaned at every VIP. It gets time consuming and expensive.

You can do a VIP that does not contaminate the O2 cleanliness....

 

[Divin'Papaw]

You can do a VIP that does not contaminate the O2 cleanliness....

Doing the VIP yourself … certainly. Most shops won’t resticker them O2 clean without cleaning them again as they have no knowledge of where they’ve been filled and with what. Which points to another issue with the whole O2 clean concept. The label technically means nothing to a fill operation because they have no clue what’s been put into the tanks. An O2 clean VIP sticker is really meaningless. It was true at one point in time and only at that point in time.

And then you have the whole valve topic. None of the valves we use in scuba can ever be technically compatible with O2 regardless of cleaning. The design doesn’t allow them to be used with O2 when you look at the requirements for oxygen valves. However we PPB Nitrox and also use high O2 deco gases all with valves that aren’t designed for O2.

The whole set of regs are unnecessarily rigid at points. Real world data can’t support the regs that are in place or there would be data regarding regular fill issues with 32-40%. Where does 23.5% come from? Where’s the data showing that 36% is of a significant enough increased risk of combustion to require cleaning?

 

[tursiops]

Doing the VIP yourself … certainly. Most shops won’t resticker them O2 clean without cleaning them again as they have no knowledge of where they’ve been filled and with what. Which points to another issue with the whole O2 clean concept. The label technically means nothing to a fill operation because they have no clue what’s been put into the tanks. An O2 clean VIP sticker is really meaningless. It was true at one point in time and only at that point in time.

And then you have the whole valve topic. None of the valves we use in scuba can ever be technically compatible with O2 regardless of cleaning. The design doesn’t allow them to be used with O2 when you look at the requirements for oxygen valves. However we PPB Nitrox and also use high O2 deco gases all with valves that aren’t designed for O2.

The whole set of regs are unnecessarily rigid at points. Real world data can’t support the regs that are in place or there would be data regarding regular fill issues with 32-40%. Where does 23.5% come from? Where’s the data showing that 36% is of a significant enough increased risk of combustion to require cleaning?

There you go, trying to be logical when you are talking about CYA industry regulation adopted as part of the CFR.
The issue isn't really whether it makes sense, it is whether if something happens whose butt is on the line.

 

[SomeGuy509]

There you go, trying to be logical when you are talking about CYA industry regulation adopted as part of the CFR.
The issue isn't really whether it makes sense, it is whether if something happens whose butt is on the line.

Haha, as someone who has worked in two very regulated industries a truer statement cannot be said.

 

[boulderjohn]

The issue isn't really whether it makes sense, it is whether if something happens whose butt is on the line.

Absolutely. Set up rules that people are not likely to follow, and it won't be your fault in the unlikely event something goes wrong.

 

[Jcp2]

Bumped into the 23.5 rule when getting cylinder VIPed yesterday at one shop, They wouldn’t fill banked nitrox with a VIP from their shop unless it was O2 clean. They looked at my LP72 and between the valve rebuild, the tank cleaning, and the inspection fee, it would have been the same as buying a used Al80 from their shop that was already O2 VIP by them. So I left it at air only. I’m going to bring my other tank to another shop across town to VIP next week and see how they handle the same scenario.

 

[Jcp2]

The other shop follows the 40% rule for their banked nitrox and also does technical custom blends, so requires O2 clean VIP for the latter. They also require an official yellow and green label to be affixed to any tank getting nitrox fills whether partial blended or baked. Otherwise air fills only.

 

[rob.mwpropane]

The other shop follows the 40% rule for their banked nitrox and also does technical custom blends, so requires O2 clean VIP for the latter. They also require an official yellow and green label to be affixed to any tank getting nitrox fills whether partial blended or baked. Otherwise air fills only.

Isn't it dumb to not fill any tank from banked eanx? Where is the danger? I can understand PP fills, but then in the same sense I've come across shops that will only fill nitrox if it has the "been cleaned for up to 40%" sticker....then they'll proceed to PP fill? With 100%. What? Some LDS confuse me. Can you O2 clean for mixes up to 40%? It's either O2 clean or it's not.....right?

Then you have those same shops that once they get to know you, hand out VIP stickers and PP fill with your tanks that haven't been O2 cleaned at all...

I know it all falls back to their compressor, their rules but come on..

 

[Ulfhedinn]

The "yellow and green label" is frustrating to say the least. Only found one shop near me that needed it. I don't get my feels there anymore since they started that rule.

 

[kelemvor]

O2 clean tanks NOT needed if the shops premix and fill your tanks from banked nitrox. If they have to do partial pressure blending in your tanks, then you DO need O2 clean tanks.

This is how it works at every shop I've ever used. If they bank nitrox you don't need oxygen clean up to 40%. If your tank will see anything more than that as with blending in your tank then you do. Simple, and universally done this way. Well perhaps except where scared silly works. First time I've ever heard of someone wanting oxygen clean for preblended nitrox fills.