Besides the obvious hydro-test requirement, has anyone recently had to deal with push-back from either aviation O2 fillers, dive shops, or welding gas suppliers about filling green medical O2 bottles? I read a bunch of threads here on VAF about how lots of companies get squirrelly or simply refuse to fill, but most of those threads are pretty old. I'm planning on putting together a DIY system and am worried that nobody might be willing to fill it.
Even though those threads are old, most of it still applies:
- The medical bottles usually require a prescription to fill (maybe not hard to get from your friendly Dr)
- Most places don't actually fill them, they simply take yours and give you a filled one. This is important if you have an odd size bottle for whatever reason.
- Presumably you need O2 cause you are going high and far, consider the difficulty of getting a replacement/refill enroute and/or your destination (maybe no medical O2 supply place nearby/reasonable?)
All of those factors made me build my system using the smallest, commonest welder O2 bottles available, which is basically the O2 bottle that comes with the cheap HF torch kits you can buy, which I think is about 20cuft. I went to the local welding supply place, asked for their smallest bottle that they keep in filled stock, and bought a filled tank for ~$120, a pediatric regulator and oxymizer cannulas on eBay. When my bottle is empty, it's about $15 to trade it in again and get a full one, at any welding supply place, and no questions or hassles given. Also, since you are just trading it in each time, you don't have to worry about hydro test etc, the new one is always good to go. Biggest downside is that the 20cuft bottle is heavier than an equivalent volume medical bottle, mine is about 16lbs, but it's rare I am weight constrained anyway, plus I built a little cradle to effectively put in under my right seat passenger, instead of adding to cargo CG.
They also said they would fill my nice odd-ball size bottle if I brought it to them, but they don't do any actual filling there and it would be sent out on the daily runs, takes about 3-5 days to come back. One place I called I mentioned something about aviation and the conversation was pretty much over at that point. I think it all depends on what you available in your area, SCUBA shops aren't exactly abundant here, but maybe in Fl, that is a better alternative etc. I was more worried about flying through the midwest, and I figured welders supply shops are a dime a dozen, even in Nowhere Muni Airport KS. Turns out I have never really needed to refill on the road, so there's that.
PS: This is all presuming you don't care about "aviators breathing oxygen" and all that debate (not trying to start that here, it's been beat to death plenty of other places). But, just as a safety precaution, I take my latest refill each time and take a few puffs at the house, wait to keel over. In the airplane, I am monitoring with a spO2 monitor anyway, so if I was breathing something besides O2, my sats would go down.