oxygen cleaning for nitrox (partial pressure) fills

[barnacleben]

...Every aluminum cylinder we sell is oxygen cleaned at Luxfer's factory...for use of up to 100% oxygen.

luxfer's own specs state that an O2 cleaned tank is only suitable for use with high O2 concentrations if (quote):
# The cylinder must have been properly cleaned, tested for cleanliness and maintained in a proper state of cleanliness for oxygen service in strict accordance with the Code of Federal Regulations (CFR), specifically U.S. Department of Transportation (DOT) CFR49 173.302(b).
# The cylinder must be equipped with an oxygen-compatible valve and be filled only by oxygen-clean, properly maintained filling equipment dedicated to oxygen service.
(close quote).

the hitch here is that an oxygen-compatible VALVE must be installed in a "clean room" environment in order to preserve the oxygen-clean status of the tank... maybe people don't realize this or i was misinformed.

:11doh: in any case, most scuba outfitters seem to be selling "nitrox ready" tanks that aren't really oxygen cleaned.

 

[barnacleben]

Every Luxfer tank we sell is oxygen clean. All of our inventory is ordered O2 clean and costs no more than a standard cylinder. Look for the green warning label, it states the cylinder is cleaned for oxygen use (vs the red label for air use)

Lee
www.seapearls.com

same unresolved issue as above (and from the first post to this thread!) are "oxygen cleaned" tanks still oxygen clean after they are unsealed and fitted with a valve? one answer is "no," unless the valve was installed in a "clean room." perhaps divers are running around with partially oxygen cleaned tanks without realizing it.

 

[Mark Vlahos]

same unresolved issue as above (and from the first post to this thread!) are "oxygen cleaned" tanks still oxygen clean after they are unsealed and fitted with a valve? one answer is "no," unless the valve was installed in a "clean room." perhaps divers are running around with partially oxygen cleaned tanks without realizing it.

In the real world where you take your gear diving NO cylinder is completely "Oxygen clean."

Lets look at a purely hypothetical situation. You purchase a new diving cylinder and have that cylinder prepared for your use. Since you want to dive Nitrox and the shop you use does partial pressure fills you want the cylinder cleaned for "Oxygen Service". You have lots of time and money so you get the cylinder cleaned at a facility where they will do ALL of the work in a clean room. The cylinder is completly cleaned, the valve is rebuilt and cleaned, everything is perfect. You know that the shop you will be using takes similar care with all of their supply equipment so we can completely rule out any contaminants ever coming in from where you get your fills. So far all of the possible contaminants have been completely eliminated, right?

NO!

As soon as you take your cylinder out of the clean room to go diving you expose the valve face to contaminants, and during the filling process some of these contaminants can enter your cylinder. Later when you attach your regulator it makes contact with the valve face and could possibly introduce more contaminants into the system. If any traces of contaminants from your regulator are left on the valve face, when the cylinder is filled for your next dive, those contaminants can be carried into the cylinder.

No system used for SCUBA diving is 100% perfectly clean, it is a practical impossibility since you NEED to expose it to the diving environment to actually dive. All of the cleaning, and other precautions are in place to keep the contaminants down to a VERY low level, but they can not completely eliminate them. This is why blenders fill high oxygen content gasses very slowly in an attempt to eliminate heat from the fire triangle.

So, in answer to your original question. NO cylinder that is used for SCUBA diving regardless of how or where it was prepared or cleaned is completely free of contaminants.

Mark Vlahos

 

[DEEPLOU]

EveryLuxfer tank we sell is oxygen clean. All of our inventory is ordered O2 clean and costs no more than a standard cylinder. Look for the green warning label, it states the cylinder is cleaned for oxygen use (vs the red label for air use)

Lee
www.seapearls.com

I noticed that. And the valves you send are O2 compatable also.

BTW: you and XS only distribute the O2 clean Luxifers, who distributes the "red label"?
(actually don't really want to know)

jbliesath
All well and good....however, most shops are going to charge you a VIP before filling anyway. Buy them O2 cleaned or just buy tanks and have the shop O2 clean them....you are going to pay either way....

I say any shop that charges you for a VIP and fill when you just bought a new tank from them has a lot of nerve!

barnacleben

same unresolved issue as above (and from the first post to this thread!) are "oxygen cleaned" tanks still oxygen clean after they are unsealed and fitted with a valve? one answer is "no," unless the valve was installed in a "clean room." perhaps divers are running around with partially oxygen cleaned tanks without realizing it.
Today 03:23 AM

Getting a little Anal aren't we?
How about y'all let us know if your LDS has a "clean room" dedicated to O2 tanks and valves.
Bet the answer is ZERO.

 

[dflipp]

Perhaps XS Scuba can address this question:

I went to my LDS this week to buy a new XS Scuba Aluminum 100. I read on the XS website that all of their cylinders are shipped O2 clean. When I got to the shop, I was told that I would have to pay an extra ~$40 to have it "re-cleaned" if I wanted to have it filled with nitrox. They use partial pressure blending. They claimed that their distributor had recommended this to them. Since it is so clearly stated on the XS website that the cylinders are ready for O2 service from the factory I felt like the LDS was trying to charge me for a service I did not need and left without the cylinder. Why would the distributor contradict the information on the XS website?

This particular shop is very strict about following safety procedures when doing partial pressure fills. This is a good thing and I respect them for that. But in this case it seems they are being a bit anal.

 

[Mark Vlahos]

Perhaps XS Scuba can address this question:

I went to my LDS this week to buy a new XS Scuba Aluminum 100. I read on the XS website that all of their cylinders are shipped O2 clean. When I got to the shop, I was told that I would have to pay an extra ~$40 to have it "re-cleaned" if I wanted to have it filled with nitrox. They use partial pressure blending. They claimed that their distributor had recommended this to them. Since it is so clearly stated on the XS website that the cylinders are ready for O2 service from the factory I felt like the LDS was trying to charge me for a service I did not need and left without the cylinder. Why would the distributor contradict the information on the XS website?

This particular shop is very strict about following safety procedures when doing partial pressure fills. This is a good thing and I respect them for that. But in this case it seems they are being a bit anal.

Did the specific cylinder in question come "from the factory" with the valve installed? If the valve was installed did the specific cylinder in question come "from the factory" with pressurized air in it?

If the answer to both of these questions is yes, then the cleaning done at your local shop should be entirely unnecessary. If the vavle was off the cylinder when it arrived at your local shop, then they do have a point to argue, although if the cylinder was sealed in a box and a plug was threaded into the top of the cylinder, and the valve was sealed in a plastic bag then this point is not a strong one.

I have probably never been anywhere near your local shop but I would guess that either they are being over cautious, or they are trying to get a few extra dollars from you.

A while back I purchased two new pressed steel cylinders from a local shop here in Southern California. I told the owner that I wanted them filled with Nitrox, he said that he would need to clean the new cylinders. I told him that I thought the new cylinders from PST came from the factory cleaned already. He was under the impression that they were only cleaned for premixed Nitrox up to 40%, but that he would call and check. I told him that it would be a few days before I needed the cylinders and that he should do whatever was required to safely fill the cylinders.

He called and checked, and was told by PST that the cylinders and valve were indeed cleaned for up to 100% oxygen. He did not charge me for an extra cleaning, he apologized for his misunderstanding, and had the cylinders ready with the right mix in them when I came back a few days later.

In my case it was an honest error on the part of the shop owner. Your situation may be different, I don't know.

Mark Vlahos

 

[dflipp]

I have a pretty good relationship with the shop so I suspect that they are just being overly cautious. But it seems odd that the distributor would tell them to clean the cylinder since XS advertises them as "02 Clean".

From the XS website:

"New Luxfer scuba cylinders manufactured from January 1, 2000 , until December 31, 2004 , will have been cleaned for oxygen service at the factory and sealed with an oxygen-compatible cap before being shipped. However, starting on January 1, 2005, Luxfer now provides XS Scuba only with oxygen-clean scuba cylinders."

 

[Leadking]

think about this;

Do you believe every e-medical oxygen cylinder shipped from Luxfer is "re-cleaned" when it arrives for its first fill. Luxfer is a reputable company supplying oxygen cylinders to the medical industry in numbers that anyone in the dive industry would find hard to believe. I am confident when Luxfer says they're O2 clean I am confident they are.

Lee
www.seapearls.com

 

[barnacleben]

In the real world where you take your gear diving NO cylinder is completely "Oxygen clean."


Mark Vlahos

mark,

thank you for explaining this to me in layman's terms.

i now see your point about the unavoidable contamination which stems from fills and normal use.

in this new light i can also see how scuba retailers are careful to market "nitrox ready" instead of "oxygen cleaned 100%" since in practice the 100% oxygen compatibility cannot be achieved--nevermind maintained. it is aggravating, however, that attorneys appear to be behind the manufacturer specifications (such as luxfer's) which are so severe as to irrelevant, or worse, misleading... as opinions on this thread attest.

thanks again for the friendly advice.

maybe i'll just rent my nitrox tanks for a while eyebrow

ben

 

[XS Scuba]

Hi dflipp:
We do not recommend to any of our XS Scuba Dealers that additional oxygen cleaning is required to any new Luxfer cylinder purchased from us which is sealed from the factory. The sticker attached (green border) to each cylinder states, "This cylinder was cleaned for oxygen service and oxygen-enriched service at the Luxfer factory." It goes on to state that it is the responsibility on the user to maintain this level of cleanliness if the cylinder is used with any gas mixture in which oxygen exceeds 23.5%. All Luxfer scuba cylinders we sell are manufactured, cleaned and tested for oxygen cleanliness in the exact same procedure as Luxfer medical oxygen cylinders.

Perhaps XS Scuba can address this question:

I went to my LDS this week to buy a new XS Scuba Aluminum 100. I read on the XS website that all of their cylinders are shipped O2 clean. When I got to the shop, I was told that I would have to pay an extra ~$40 to have it "re-cleaned" if I wanted to have it filled with nitrox. They use partial pressure blending. They claimed that their distributor had recommended this to them. Since it is so clearly stated on the XS website that the cylinders are ready for O2 service from the factory I felt like the LDS was trying to charge me for a service I did not need and left without the cylinder. Why would the distributor contradict the information on the XS website?

This particular shop is very strict about following safety procedures when doing partial pressure fills. This is a good thing and I respect them for that. But in this case it seems they are being a bit anal.