Posted by roakey on August 15, 2001 at 11:37:04:
In Reply to: Hey :) Just the answer I was counting for :). posted by Maciek on August 15, 2001 at 10:21:52:
>>Do I understand correctly that not all tanks are suitable for O2 clean?
I don’t understand the question. If you’re asking AL vs. Steel, either can be made ready for oxygen service.
Any cylinder that can pass a visual should be able to be made ready for oxygen service.
>>One thing, I don't quite get is depresurizing cylinder and letting regular air in.
>>That will sure bring many hydrocarbons inside (as they are in regular air).
>>Is it simply not enough to bother?
Not enough to bother, especially if you’re talking about simply running the pressure down to zero and not taking the valve off. Heck, right after cleaning the valve is off and the cylinder’s full of “unclean” air -- nothing you can do about that! I just wouldn’t leave the valve off for any period of time.
Now you might worry if you were to take the valve off, put the cylinder in your garage, start you car and leave it running for an hour or two. Or worse, take the valve off anywhere near the LA area. :-)
After taking a few shots at dive shops in my last post, let me come to their defense for a minute. There are a lot of idiots that work in dive shops, but they’re even more idiots that are just divers. I really don’t blame a shop that is *honstly* a bit jumpy about someone they don’t know from Adam coming in to get a Nitrox fill in a personally owned cylinder. In most cases casual conversation sprinkled with a few good questions should give the shop a good feel if the diver knows how to maintain the cylinder. This is why it’s nice to get a good working relationship with a shop of your choice. If they know you and trust you, things become much, much easier.
Another option that I personally like is for the shop to explain the dangers of blowing O2 into an unclean cylinder and then make the customer stand beside it while they do it. :-)
Out here in Colorado Nitrox is really viewed with suspicion by many shops. I bet I own one-quarter of the personally owned Nitrox cylinders in the state, and my three friends own the other three-quarters (I exaggerate, but you get my drift :-)). Nitrox in Colorado is almost completely doled out in rented cylinders, and almost exclusively for Nitrox classes before the wimps head to Cozumel where the DM won’t allow them more than a 20 minute bottom time anyway. I have a good working relationship with a local shop and have no problems getting fills, even though I’m “lacking” the big Nitrox bumper stickers that most shops feel that they must emblazon their cylinders with. I merely have the MOD and my name stenciled on the side, a visual sticker/O2 service sticker on the bottom and my duct-tape mixing information on the shoulder.
By the way, I feel that the Colorado shops are completely missing the boat on Nitrox, because they should be marketing it as an altitude gas too. I’m going to 75 feet this weekend in a 10,000 foot-high lake. 75 feet translates to an EOD of 110 feet, and with the right back gas that 110 EOD translates right back to a 72 foot EAD!
Sorry, I got WAY off the topic :-)
Hope that answers your questions.
Roak